Coolant/Antifreeze

[flyu2there]

While changing out the three decayed hoses in my cooling system I lost some antifreeze, actually it went into a dirty bucket, some had rolled down the side of the engine....I needed 4 gallons of new. The Cummins Store was closed, I usually buy Fleetguard that meets DD Spec, but Joe Baggadonuts Heavy Truck Repair was open. I acquired the anti freeze from him and asked him some questions, his answers puzzled me so that I did some research and now I am even more confused.

There are basically two types, ethylene and propylene, the later being far less toxic to animals and humans. Ethylene glycol provides the best heat transfer and is the product used in heavy duty engines, and it never wears out. What does "wear out" are the additives in coolant. Extended life antifreeze only means that the additives last longer. Additionally, it is best to buy pre-mixed (50-50) antifreeze because it is mixed with de-ionized water. I have always mixed it and used distilled but evidently that is not a good answer; tap water with chlorine and high amounts of TDS (total dissolved solids, calcium and the like) is really a no no. Many of the lower priced antifreeze products are made from recycled or used antifreeze. Thats what my reading showed.

Back to Joe Baggadonuts. He said that all ethylene antifreeze is the same whether you buy it from Detroit Diesel or Wal-Mart. The additives are much the same in all of them; evidently there are several government agencies monitoring this and set the specification because it is considered toxic. Further the coolant filter (sounds like it contains a bunch of rocks in it when new) continually refurbishes the additives (SCA's) to prevent scaling and jelling. The biggest danger he stated is the running of too high concentration of ethylene.

So my question is, was Joe full of sierra hotel india tango or was he right...I dunno!

John

[Jon Wehrenberg]

Maybe.

It has to meet the DD spec, and if it does it will say it. If it does not say it you can have potential problems of a serious nature due to cratering on the rear of the cylinder liners. The chemistry in our antifreeze protects the nitriding on the liners. The wrong chemistry also causes silicon dropout which ultimately plugs the radiator core causing the severe loss of heat transfer.

Extended life antifreeze (like normal DD spec antifreeze) does have a life, expressed as something like 6 years (instead of 2) or 750,000 miles (or some such high mileage rating). That was developed by Caterpillar and carries the spec EC-1. Never ever mix the two types of aniti freeze and if switching from one to the other the system needs to be flushed.

Brian did reseach on the anti-freezes we use and had a presenter at Spearfish do a mini seminar on it. The EC-1 spec antifreeze is so good I am going to use it at my next change. When using EC-1 you must use a blank cartridge in place of the one that replenishes SCAs.

[Orren Zook]

John,

I wouldn't use an 'automotive' antifreeze, primarily for the silicon levels of those products. You'll get the dropout that Jon mentions in an earlier post if you use those products. While you're at a HD parts facility pick up a few test strips to check/test the Ph of your antifreeze. Be sure that your coolant is within the prescribed Detroit Diesel specs. You can buy pint containers of SCA to bring the levels up to snuff and then keep them at that level with the additive included in your replacement filter.

Remember that 50% of all engine failures are directly related to cooling system problems.

[flyu2there]

I dumped in 4 gallons of Delo which, according to the container, is compatable with everything, including Detroit Spec, Navstar, etc and EC-1. I mixed it with distilled water and then started doing the research. Mistake 1, mixing with distilled water, now I am wondering about the EC-1. I don't spect that 4 gallons will hurt anything, I'll get a test strip and check.

John

[truk4u]

Brian did a great job on the green machine and I have the EC1 stuff. I now need some antifreeze and cannot find the Texaco Extended Life Concentrate, Cat - EC1. Texaco has Extended Life, but it's for auto's and light trucks.

Any thoughts on a source for this stuff?

[flyu2there]

Looks to me like there are only two antifreeze/coolant makers on the planet, at least the ones that produce ethylene and propylene based glycols. The biggest turns out to be Honeywell but the biggest in terms of heavy duty applications is Old World Industries. They both color code the same, green, pink, purple and orange. As I read it the green stuff has few, if any additives, the pink and purple are the heavy duty's with all of the SCA's and the orange is the extended life organic acid antifreeze.

Jon was correct regarding the mixing of the red orange with any other, seems it causes some big issues. Joe Baggadonuts was also right, they are really all the same save concentration and additives and dye. Detroit uses Detroit Power Cool 3000 as an additive as it has nitrites, course that is also made by Old World and marketed under their brand, Penray Power Cool 3000--same stuff. Detroit also authorizes 95% water and 5% power cool as a usable coolant if the weather is warm enough that one does not need freeze protection. I suspect one could use the green stuff with the powercool additive, except it would probably be brown stuff.

I found this site very helpful, as it kind of clears the whole question up...
http://www.freightlinerchassisownersclub.org/coolant_info.htm

Suffice to say, three way test strips and a supply of power cool should keep everyone out of trouble.

John

[LarryB]

Thanks for the info John. When I bought my bus from Marathon a condition of the sale was a 100,000 service. the Company [MidLane]that does the contract servicing for Marathon put the Green stuff in after changing out the coolant.
If I read you correctly, I need to 'test' and maybe change out the coolant again?

[rahangman]

OR if you are really concerned (and aren't we all) about actual Coolant Contents, a small amount drawn per instructions from your system and sent to a testing facility for minute detail concentrations, etc. it can be done for about the same price $$$ as the test strips, giving a nice print out that of course needs interpretation, but, takes most of the guess work out of the whole process. Not quite as easy as test strips, but ...

[garyde]

My last Service before Oklahoma City, the Detroit Diesel /Allison Service center I go to recommended not using the extended life coolant because of potential electrolysis. He installed the two year coolant and recommended it be checked after one year.

[Jon Wehrenberg]

I would be very interested in finding out where the DD/Allison folks got that information and where we could find it.

I admit to being a cynic, and really hate it when technical folks say things based on their gut feel rather than facts. According to what we learned in Spearfish the EC-1 coolant was tested extensively and has all the good properties we require, but no bad characteristics. Could the comment made be because Caterpillar developed the extended life coolant and gets a few cents for every gallon sold?

I admit to not being a big fan of the current 2 year life coolant because that stuff has a propensity for plugging radiator cores.

[flyu2there]

Here is the DD list of approved coolants:

http://www.detroitdiesel.com/Support/On-Highway/Manuals/Lubricants_Fuels_Coolants/Power_Guard_Oils/index4print_93K217.asp

Now, after reading that, try this:

http://www.expertdiesel.com/cavitation.htm


Couple of potential trouble spots. Apparently OAT and HOAT antifreeze is much more common than conventional charged antifreeze. Not all sellers of the stuff are subscribing to the color codes (apparently)...Delo's OAT is green, easy to mix with conventional. Also it is apparent that mixing with tap water with high levels of total dissolved solids is also a trouble, probably wise to buy premixed. Sample for the test strips should be taken low in the system, not in the surge tank. The coolant filter should be changed annually. Long periods of sitting results in a very powerful mixtures of SCA's being dispensed from the filter on start up, once again, apparently just as bad as no sca's.

[truk4u]

After reviewing the list, it would appear that any of the ELC's could be used as long as they comply with EC-1.

EC-1 is Caterpillar's industry specification for an extended service, or long life, coolant. EC-1 defines the minimum requirements of a long life engine coolant and coolant extender intended for use in Caterpillar engines. EC-1 defines the physical and chemical properties, compatibility characteristics, bench and performance testing, and field testing requirements. A coolant meeting EC-1 also meets ASTM D4985. What makes EC-1 unique from other coolant specifications, is the field-testing. Field-testing establishes the practice for evaluating the ability of a long life coolant to provide acceptable corrosion control and cooling system performance with significantly reduced or no maintenance additions of inhibitor in field service.

[Denny]

The W. W. Williams Detroit Diesel and Allison facility that I use gave me the same info as Gary's. Use the two year antifreeze and check it periodically.

[Jon Wehrenberg]

I am curious as to why that advice is being given. If there is a good technical reason I can understand the advice, but if they just don't want to pay Caterpillar royalties that is not fair to their customers.

I would be willing to wager few people change their coolant every two years or change the conditioning filter as specified. If DD allowed or even recommended the extended life at least the engines would not lack coolant system maintenance. Coolant related failures on engines are a fairly high percentage of the reasons engines are trashed.

[Ray Davis]

A buddy of mine works for DD. I asked him the same question a year or so ago. Here's his reply. I'm also attaching the DD document he forwarded to me.


Different manufactures of coolant have different colors. The key is the
base make up of the coolant. There are 2 basic groups.

Ethylene-Glycol: This is the basic coolant. It is good for 1-2 years.
Organic Acid: Some manufactures say this is good for life or 500,000 miles
or...... That is great if you don't have a problem (leak, exhaust gases in
coolant, ect). This come in two types NOAT and OAT (with nitrites and
without), this depends on the engine and the amount of aluminum in the
engine components). If this coolant gets mixed with Ethylene Glycol (EG),
the entire system needs to be treated as if it is 100% EG. In other words,
it is NOT good for life.

You will here other terms like Propylene Glycol, this is sold as an
environmentally friendly coolant but it does not cool as good as EG.

I have attached our Coolant Selection document for addition reading or
forwarding to friends with questions.



And from a second email:


Power Cool - This is EG/water and a SCA(Suplmental Coolant Additive -
package that protects the metal). This is good for 2 years in your
application. The more mile you put on, the faster the SCAs burn off.

Power Cool Plus - This is EG/Water and OAT (Organic Acid Technology
additive package). This is good for 4 years in your application.

DDC does not sell a OAT coolant, only an OAT SCA.

Texaco and others sell OAT coolants, don't use any OAT coolant.

[Steve Bennett]

I have been leery of the extended life coolants, as I have seen extensive corrosion, and leaks in the welded recovery / surge tanks of various coaches that have come with factory initial fills with the Extended life coolants. We have seen a fair amount of leaks in the surge tanks on Foretravel coaches with the Texaco Extended life coolant. I have never seen a coolant leak on the same tanks in the older coaches with the standard coolant. We have also had coolant leak in other coaches (Country Coach) with the extended life coolant that appear to be caused by corrosion in in welded tanks. This is obviously not a scientific study, but has kept me using standard coolant with frequent servicing.

[Ray Davis]

I had also meant to say that with both of my last two coaches, when having them serviced at Marathon, they used regular coolant in them. I purchased some test strips, and meant to check that at OKC. Still need to!

Ray

[dale farley]

I was planning to change my coolant to the extended life Fleet Charge, but this is thread is making me wonder. When I bought my bus, it had been serviced by Prevost and Marathon in Dallas (somehweree around Dallas) and it had the regular green antifreeze in it.

When regular antifreeze is recommended, exactly what kind is it that is being used in our buses? What is Marathon installing?

[Ray Davis]

With my two buses Marathon installed the regular green coolant. This was at both the Florida and Texas facilities, so I assume it is company-wide policy.

ray

[GDeen]

Ok, so which one is the green one and which one is the red or other colors?

Mine has green in it, but all the low Si, HD diesel coolants I have found in parts houses and truck stops thus far are red (or purple)??:confused::confused:

[Ray Davis]

There's the rub. Generally the green is the regular life, eythelene-glycol coolant, good for 2 years.

Some of the red/purple can might also be the same.

The trick is to determine whether or not extended life coolant was put in your system.

FYI, while having my first bus serviced at Prevost, they put in regular life, EG coolant (green) as well. I've never had any shop put in or ask if I wanted to change to extended life.

Ray

[flyu2there]

Probably the best answer about antifreeze that I found came from a large PACAR dealer, they sell and service Peterbilt and Kenworth, they have Detroit, Caterpillar, Volvo, and Caterpillar engines....buyers choice. They have several 55 gallon drums of Green 4985 Coolant, they then dump in the SCA's that the engine manufacture recommends that will "charge" the anitfreeze, be it Powercool 3000 or Fleetguard DCA4. Its all green and they charge the antifreeze for the particular engine manufacturer recommendations. The service manager did tell me that one of the most neglected things they find was the coolant filter which, aside from removing chunks of debris and scale from the system, also revitalizes and recharges the chemicals each engine manufacturer recommends. Obviously that leads to the coolant filters and the "stuff" inside of them...it must correspond to the SCA's that were originally added to, or came with the antifreeze change ....I never knew that! Changing out the antifreeze every year or so may be a bit of an overkill for our types of operations, remember the truckers put on sevral hundred thousand miles each year, if they like to eat. The PACAR dude went on to say that what wears out the coolant additives, remember glycol lasts forever, is the starts and stops....his final recommendation was to monitor coolant levels and SCA's regularily, when they cannot be kep't withon tolerances, change it out. Sounds sage to me..........

John

[Jon Wehrenberg]

DD Power Cool is Magenta (kind of red and / or purple), but at the seminar in Spearfish the presenter pointed out that colors are not an indicator of the type of coolant. They may have been at one time, but not any longer.

[flyu2there]

It is apparent there are a few renegades in the bunch, color coding wise that is...Caterpillar is at the top of the heap! I read a post not too long ago where Lew had to remove his pressure cap on the surge tank with channel locks due to rust or gunk. I'll bet his site glass looked like the Missippi River as well; trouble is, you could be spot on and mix a couple of off color compatables and you too would have a brown site glass. Stay Green as Al gore says....:D:D:D:D

[truk4u]

Some are missing the point! Not every Extended Life Coolant has the EC-1 blessing. Just go to someplace like Auto Zone and read the Extended Coolant labels. You won't find any reference to the Cat EC-1.

Why on earth would you want to full around with 2 year coolant changes (that you probably won't do) and SCA charged filters when you can safely do the proper ELC.

Lets just be sure to compare apples to apples.... Was I the only one at Spearfish other than Jon?

[flyu2there]

Sheepster!

You could run cat pee, sheep pee, or Michelob Light in your radiator for as much use as these busses get ,probably never see (although you may smell) a difference in wear or problems.

I am sure that Cat EC-1 is a fine product, go for it! The "true" green stuff is just fine as well. Sometimes we have to agree to disagree! Two year changes, kinda think that's a myth, on condition is a better answer....seems that's what the big kids do.

:D

[BrianE]

Here is what we were able to gleen from our presentation at Spearfish (I took notes). This presentation was given by the regional Chevron jobber. Their knowledge of Chevron products seemed to be excellent. I agree with both Jon and Orren's comments in this thread, they attended Spearfish also.

1. Coolants that are a shade of red can either be extended life or not.
2. The only tested extended life coolants for heavy duty diesel engines have the Caterpillar EC-1 specification.
3. Green coolants never carry an EC-1 specification.
4. Detroit has elected not to produce an EC-1 coolant.
5. Mixing non EC-1 coolant with EC-1 is not harmful to an engine except that it no longer retains it's extended life properties.
6. Since Chevron now owns Texaco their EC-1 coolant is Delo Extended Life Coolant: http://www.chevrondelo.com/en/products/coolantantifreeze/default.asp
7. Caterpillar developed and markets EC-1. They also developed a test strip and lab analysis system which EC-1 users can avail themselves to: http://www.cat.com/cda/files/87058/7/elcfaq.pdf
8. The use of a premix coolant eliminates water quality concerns.

Here is a very good article by Caterpillar for RV applications. Intended of course for Cat engines, it seems to be in line with what we recognize as good practice with our DD's. http://ohe.cat.com/cda/files/517742/7/LEHT9288.pdf

Bottom line is extended life or not, keep it clean, test it, keep it full, and change it at recommended intervals.

[garyde]

Another issue in changing the coolant. With RV's we have a coolant loop for Webasto and the hot water. If they are not fully drained, you will be mixing new with old. I had my valves closed when I replaced my coolant. The Detroit people didn't seem to have a problem with clsoing that off.
If your replacing the coolant every two years or so, thats probably 20000miles or less. Probably not a big issue.

[dale farley]

Brian,

In reading the articles and talking with others on the forum, I thought the general consensus was that it was too big a hassle to drain/refill the heaters, so I did not do mine the last time I changed?

I used the green stuff again, so I didn't make any significant change to the antifreeze. Can someone who has drained the entire system tell us how much trouble it was it to refill?

[Jon Wehrenberg]

I replaced a lot of converter installed coolant hoses on my last coolant change. I still had coolant in the system, and I suspect places that have low spots such as the HW tank, the bus air heat exchanger and probably some Webasto heat exchangers still held old coolant.

Since I really do not know the actual system capacity beyond what the owner's manual says, and I can't verify but I am assuming quite a bit of old coolant still remains.

But if I drain, empty, drain empty, etc. making sure the bus is up to temperature each time before I drain I am confident the old coolant that remains has been significantly diluted, so much so that it will not adversely affect any extended life coolant. I am sure there are vent fittings and low spot drains that could be opened to maximize the amount drained.

Changing coolant, even if the same is re-installed is a pain so dedicating a day to filling and draining seems like a good investment in time to extend the interval between changes.

[flyu2there]

Jon,

This thread has about seen its day, however I think that it raised awareness of the importance of maintaining ones cooling system. I have my doubts whether or not the coolant needs be changed at regular intervals, say two years, or longer with the extended life coolant. I think it is common knowledge that Glycol does not wear out, what wears out are the additives to protect the engine, the organic compounds have a slower "burn" rate than the inorganic. I did a fair amount of research on this topic, and while I certainly claim to be no expert, it is apparent that if the proper ratio of SCA's are maintained, the coolant is still good. Looks to me like the additives in extended life coolant cannot be replaced by adding additional organic things...maybe they make it but it is certainly not marketed openly. I am positive that when adding additional SCA's cannot bring the fluid into tolerances, it is time for a change. The use of automotive antifreeze is probably not wise, however if it meets the 4985 spec, it looks to me like it is certainly ok in a pinch, provided that one adds the SCA's. My best guess is that there is a point where additional SCA's do not work, the coolant as we know it, is worn out and time for a change; that may well be two years or five years and in rare cases ten years!

John

[Jon Wehrenberg]

At the United Engine seminar I asked about the life recommendations for Transynd. They list 4 years and XXXX miles if the coach does not have a retarder, or 4 years and 1/2 XXXX miles if it does. The presumption is heat is the enemy because with the retarder we can bump up against the 300 degree limit. So my question was if we keep temps to a max of 230 instead of allowing them to hit 300, even if wehave a retarder, can we observe the greater limit?

The response was that when the engineers specify a limit for the life of fluids they pick in his words "a one size fits all" value. I suspect the coolant life limits are similar. As long as certain values are maintained it is likely for our average usage which is likely 10% or less than the commercial usage we can probably extend the intervals.

Having said that however, I suspect strongly (but have no proof) that the 2 cycle engines are hard on coolant and silcone dropout and the resultant plugged radiator cores was proof there was a reason for the suggested intervals. Despite adherance to the coolant maintenance schedule with my first coach the radiator had to be recored after 10 years. I don't think the series 60 is as sensitive. But the thing that keep me following the schedule is the chemistry that protects the nitriding of the cylinder liners, the failure of which will create erosion and cratering on the back of the cylinders due to the vibrations imposed on them by the combustion cycle.

What we need is a large truck fleet owner to become a POG member and to educate uson what is really important for owners to maintain.

[flyu2there]

A friend of mine owns Swift but he's kind of a weenie and doesn't play well with others...... BTW he doesn't like Detroit, they wear out too fast...he's a caterpillar guy ....no doubt because of EC-1.

John

[phorner]

So, in a nutshell, if you change out coolant and filter every 2 years (and use those pesky test strips in between), you're basically going to be OK?

I really don't want to become a chemist at this stage of retirement, it's hard enough to try to be an electrician/engineer/carpenter/pipefitter/mechanic/bus driver :)

[Ray Davis]

So, in a nutshell, if you change out coolant and filter every 2 years (and use those pesky test strips in between), you're basically going to be OK?


Yep. Although if you read the DD manual I posted, it did say 300,000 miles or 2 years, whichever comes first! So, for you large mileage guys ..... :eek:

[dale farley]

Well, I am getting ready to change my antifreeze. It has been about two years since the last change. I have read and reread the posts on this thread and I am a little more confused than when I started.

I had made the decision to use Fleet Guard Extended life, because it is on the list of approved DD coolants. It is an OAT coolant. Then I notice that Ray's friend at DD said don't use an OAT coolant. I called several truck shops this morning, and got everything from, "any antifreeze is okay, just use Prestone" to use "Fleet Guard" in DD engines.

The one thing I've noticed is that each shop has a strong tendency to push whatever they have on the shelf at the time. I got different recommendations from 4 different shops this morning. Unless someone can really explain to me me why I shouldn't, I plan to use 100% Fleet Guard and mix with distilled water. I am going to try to drain everything possible from the bus and intend to raise the front of the bus somewhat to hopefully drain more out the rear. Speak now or forever hold your peace!

[JIM CHALOUPKA]

Dale, from Brian's post #27 of this thread:

"7. Caterpillar developed and markets EC-1. They also developed a test strip and lab analysis system which EC-1 users can avail themselves to: http://www.cat.com/cda/files/87058/7/elcfaq.pdf
8. The use of a premix coolant eliminates water quality concerns."


This EC-1 is the only product I will use until something better comes along.

Go to Caterpillar to buy it, they will not try to sell you anything else.


JIM

[Denny]

Dale,
I was advised by W. W. Williams Detroit Diesel to NOT use the extended life anti-freeze. Their reason was that is is next to imposable to drain the system in its entirety so there will be a mixture of regular and extended life anti-freeze mixed together. The new mixture will be a compromised extended life mixture and could cause damage in the future. They said drain every two years and play it safe.

[Jon Wehrenberg]

Denny is correct, but Williams is hardly unbiased.

The correct answer is either stick with the DD coolant and maintain it as necessary, or opt to go with the EC-1. If the choice is EC-1 then it is not a simple drain and fill. The system either needs to be completely drained which is somewhat labor intensive and varies with each converter and how the coach has been set up, or the system needs to be emptied, refilled with fresh water and circulated, then drained, then refilled with fresh water, circulated, then drained, etc until the old coolant is less than 20%. The 20% number comes from the manufacturers of EC-1. I think if I were to do it (I will be doing it in August) I would flush the system sufficiently to get the remaining old coolant down to less than 5%.

Changing coolant is expensive and a real pain. I am opting to use EC-1 just so I don't have to deal with the coolant change every two years.

But, for anyone contemplating EC-1 there are some critical issues to understand. Denny has the most critical thing correct. Every effort should be made to get as much of the old coolant out as possible. The second thing is to replace the coolant conditioners with dummy cartridges. You do not want to add SCAs to EC-1 coolant. EVER! The final thing to recognize is that EC-1 has a life of 600,000 miles or 6 years. We likely will not hit the mileage limit, but we will hit the 6 year limit. EC-1 is not permanent.

Good catch Denny.

[flyu2there]

Jon,

On a Country Coach, in order to completely remove all coolant, one has to remove the plastic shield.......truth hertz...

[JIM CHALOUPKA]

I agree with that drain procedure etc, the end result will be worth it.

JIM

[truk4u]

Dale,

You don't have to go to Cat for the EC-1, there are other sources less expensive as long as it complies with EC-1. Brian put Texaco in mine.

[dale farley]

The coolant that I found locally that meets the EC-1 specs is the red Zerex HD Extended. NAPA has the full strength for $15.02 a gallon. If that is what I use I will mix with distilled water.

[dale farley]

While I am changing my coolant, I want to change all/most of my hoses. I figure 10 years is getting pretty close to the end of their life although I don't see any that are swollen, etc.

Has anyone changed all the coolant hoses around the Series 60 engine before, and will I need to get all of them from Prevost or can I just buy hose and make some/all of them?

According to the manual, the system (including dash heater lines) holds 24 gallons. Does anyone know if this is close to reality for our applications? I know when I changed the coolant a couple years ago, I was able to drain our about 16 /17 gallons. I didn't drain the heater lines.

[dale farley]

I've heard some say don't use distilled water to mix with EC-1 when filling the system. Why is distilled water a problem? Peak recommends using it when mixing with antifreeze. The definition for purified water is water such as distilled or deionized that has had the minerals removed.

[gmcbuffalo]

I changed my system coolant with power cool 3000 and new filters before OKC. I thought I had done a good job deairing the system, but had one morning where the engine would not stay running. Problem low coolant. Got home from OKC and low coolant, and no leaks. Needed heat in the bus for winter, two register would not put out warm air, need deairing again.

In the future I am going to only change the coolant and filters in the engine loop at the two year mark, let it mix with the heating system coolant and monitor with test strip when I check oil for long trips and then do the same at two years again. I am threw trying to burp these babies.

May not be AR (anal retentive) but I think it will out last me, and after that it's someone else problem. I know the last coolant change before the one this year was in 2000 and the coolant looked good and tested good. I really never put much thought into it until these coolant threads. So I think my future protocol will be 200% better that the last 9 years.

GregM

[Jon Wehrenberg]

My coolant changing technique to burp the system is to run the Webasto pump to circulate coolant. I also get the engine up to temperature by doing a quick run around the block (8 miles). I then refill and circulate the coolant again using the Webasto. So far that has worked. I think getting the engine hot and having the engine thremostat open is central to purging air.

My last coolant change involved changing Webasto system external hoses so if I was going to have air entrapment that would have been the time, but it still worked OK. This coming August I think I will change to EC-1, and I am considering changing the interior Webasto hoses so I know the system will have been fully drained. I assume the technique will still work. Then with EC-1I hope I can avoid having to go through the process for a long time. It's a PITA.

[JIM CHALOUPKA]

Jon, when you changed out your Webasto hoses did you find any old hose that you thought you caught in the nick of time?

Do you think any might have leaked at any moment or were the hoses you removed actually in good condition and just old?

Did you use new hose clamps across the board or reuse the old ones?


JIM

[Jon Wehrenberg]

It was about 18 months ago that I changed the Webasto hoses and a couple of the elbows were bulged out and beginning to show signs of impending failure. Externally they lookd OK, but were clearly bulging.

I used all new clamps and I doubled them. When my EC-1 has come to the end of its life, it will also be when I will replace the Webasto hoses plus some others in the cooling system. The job wasn't that bad, so I'd rather do it prematurely than experience a failure while on the road.

I allowed some hoses on the first bus to go about 13 years and when I changed them I realized how close I was to having them fail. It doesn't seem like they should fail, but when you consider they see 14 PSI plus some very hot temps its a wonder they last as well as they do.

[gmcbuffalo]

I would really be a pis*** to drain, flush, drain, flush and drain for EC-1 and then have a bad hose blow and loose all that EC-1.

Jon even deairing each register I still had an air lock in one register that I could only remove by turning off all the other register valves. I have not been impressed with that little pump in the Webasto for circulation.

GregM

[treedoc]

Greg Could it be that the pump is weak? Rick

[truk4u]

I had to drain about 2 gallon last month when I did my Webasto circulation pump change. I saved most of the coolant and only had to add a couple quarts. I then ran the Webasto full tilt for about 3 hours with heat, water heater and engine heater getting to 170 degree's and had no air lock issues. Drove 1200 miles after and didn't have to add anything.

[JIM CHALOUPKA]

Not having done mine yet, I don't know if it is possible in a practical way?

Couldn't one keep tract of how much antifreeze came out so if the same quantity did not go back, you know you have an air pocket.

JIM:confused:

[Jon Wehrenberg]

If you do not make the switch from the DD type coolant to EC-1, and you change coolant on schedule I doubt if it is a big deal to leave some of the old coolant in the system.

But if you switch to EC-1 it is important that the system have as much of the old coolant as possible removed. I believe in Spearfish the fellow leading the EC-1 seminar said 20% was OK, but I think with a little effort we can get almost all the old coolant out with a couple of water flushes.

When I do put the EC-1 in the coach it is going to be a major project making sure every hose in the system is new or nearly new, but I think it will be worth the effort since the hoses need to be in great shape anyway and EC-1 is a good way to force myself to go to the effort.

[flyu2there]

I received a copy of this message to/from Bill Jensen from Prevost. Probably worth the read!

"My question to Mr. Jensen
We need to add coolant, once or twice each season. The coolant gets
low enough that the "stop engine" light comes on. After adding about 1/2 to 3/4 gallon, the light goes out and stays out until it gets low again. The engine doesn't seem to run hot by the gauge and no evidence of leaks is shown. Could a malfunctioning surge tank pressure cap be allowing the coolant to escape. I looked in the manual and Drwg. 0510-00 shows a cap @ 7 psi. Drwg. 0510-01 shows a cap of "over 14 psi". There is a reference on each of the above sheets that says "Prior to J-622" and "Eff. J-622". I wasn't sure how to interpret the "J-622" so I decided to ask you. Our VIN is 2PM33405S1001470, can you advise which pressure caps we should be using?

Response from Bill Jensen, Prevost Service Manager, Shell Division
The designator J-622 is the shortened form we use to make it simple to find the unit break for parts and anything else on the coach. For your VIN 2PM33405S1001470 this shortened form would be S-470. The 8th digit in the VIN number is the year. It started with the letter B in 1981 and continued up each year, skipping letters that looked like numbers. E = 1984, F – 1985, etc. The "470 is the sequence number. Prior to 1996 (T) there was no separation of the VIN numbers for XL and H series coaches. Starting in 1996 we started using the last "four" digits of the VIN instead of the last three. Plus we designated that the H series vehicles would be from 0001 through 4999 and XL series vehicle would be from 5000-9999. Thus from 1996 on we could tell what type of vehicle we were talking about from the VIN number.
That all being said we use two caps on the surge tanks. The top one where you would add fluid is strictly a cap. The lower one on the overflow line is the pressure cap and it is a 14lb cap. This was done so that venting of the hot coolant would be done through a proper tube to prevent spraying you with hot coolant. This might happen if you tried to take the upper cap off.

I hope that this somewhat explains the system and the vin number designation. I have added a sheet that explains this also."

[gmcbuffalo]

Rick
you maybe right, I don't know how to check this. I have the little pump in the Webasto unit and another one (part of the bus heating system in the roof of bay 1. Both seem to work or can at least feel them turning.
GregM