Purging a Cooling System

On another thread Brian questioned the protocol for bleeding the cooling system when refilling, especially with the Webasto and all its heat exchangers.

In the past when changing my coolant I have run the engine, eventually burping the coach. That method works, but it seemed to ultimately involve 50 miles of driving before it was filled properly.

The next coolant change I used the circulating pump on the Webasto. That worked much better and even after taking the coach on the road I did not have to add any more coolant so evidently the Webasto circulating pump will purge air from the system.

But when I do my scheduled coolant change this August I am going to use this tool which I intend to buy:

http://buy1.snapon.com/catalog/item....group_ID=12500

When I change coolant this time I will likely not have any coolant in the entire system because I will also be changing hoses. I have spoken to someone who uses this tool and he swears by it. With a vacuum on the entire coolant system he states that coolant is literally sucked into every cavity and all air is purged.

Here is another tool....Doesn't have the Snap-On name but looks to do the exact same thing.

http://www.sjdiscounttools.com/uv550500.html

Quote:

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The next coolant change I used the circulating pump on the Webasto

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When you say you used the circulating pump, did you just fire up the Webasto? Or did you somehow engage the pump without firing up the heater?

I filled the system as much as possible through the big header tank. I fired up the Webasto and watched the tank level. I kept the tank filled, and was looking for the engine and the various heaters in the coach to get warm. That would indicate circulation.

Alternately I could have run the engine, but neither was was perfect because it involved a lot of playing around. I am going to use the vacuum refiller this summer.

Thanks Jon. That question deserved its' own thread. What is the relationship of the driver heat circ. pump to the webasto system? Does it circulate coolant through the same plumbing? And to add to Kevin's comment, my Liberty also has the individual bleeders and I was hoping Jon could confirm I didn't need to deal with them. The access is not great.

Yes in the case of a Webasto system. The coolant circulating through the bus air and heat the engine and the Webasto toe space heaters is one and the same. Not so with Aquahot. I don't know enough about Espar to answer.

I have to ask, what is the total gallons of water and antifreeze in the system, yes, I know they are all differant.

A good range is 22 to 24 gallons. Different factors affect the total system volume such as the house heating system (Aquahot will differ from Webasto), and how much coolant remains in the system even after all valves have been opened.

Brain I think you will have to bleed the toe kick heaters. I had one that was not working well and and its neighbor was working . I thought it was bad, but something told me to check the individual heater for air. I bleed a small amount of air out of the toekicker and presto it started putting out heat. This was with a fully filled system that hasn't been worked on for a long time. once an area is air locked I think it will need to be bleed somehow.
GregM

I watched a Prevost tech whose name and location will not be revealed change the antifreeze on a coach. This was on a model year that had the big gate valve behind the rubber flap behind the radiator door. He closed that valve.

When I questioned him about that his response was that it traps the coolant in the heating and house systems. I later found out that it virtually eliminates any need to purge air from the system. The downside is that you can only get about 18 gallons out of the bus so some old coolant still remains in the system. I am not recommending this but passing on an observation. I will stick to doing it the hard way, mainly because I am replacing all the hosing and need it completely drained.

Forgive my youthful ignorance, but,...
why cant I pump it in through a regulator.
When I add antifreeze to a forced hot water heating system " which I dont advise and rarely ever do", I dump water and antifreeze into a barrel to be sure it goes in mixed, throw a pump suction hose in the barrel, add a watts s1156f boiler feed to act as a regulator to the supply hose, and pump through into the barrel.
Inlet and outlet hoses are in the barrel, making the barrel the beginning and the end all in one.
With the barrel method it does two things, 1 it assures a mix, and 2 as you circulate it through the system into the barrel you can see air bubbles in the mix in the barrel, when you dont see any more bubbles you are good to go.
As far as air traps go, use an auto air vent, watts 0590719 with both auto and manual venting, just put them in the system at the highest points and if kick heaters are the problem put them there also.

Today I drained my antifreeze and added new. I recently had a hose blow in the bay where my OTR heater core is and the gate valves in front of the radiator were still closed. I decided to drain the engine with those shut to see how much the engine and radiator took alone. 18 gal of 50/50 mix.

I know that I have heard mention of antifreeze from DD that is precharged. This IS NOT THE NORM, in fact it is the only green antifreeze I have ever heard of that IS precharged and I myself have never seen it. I'm sure it is available but when purchasing it anywhere else MAKE SURE:

1-the product your buying does not contain silicone.
2-If ever adding more than a gallon or 2 to check afterward with test strips and add a charging agent accordingly because 99% of antifreeze does not contain the stuff. The one I have pictured below is what I use, it will treat 4 gal of 50/50 mix.

Attachment 2090

It is about 4 bucks so it adds about 1 dollar to the cost of a gallon and I paid 11 for the antifreeze so that puts it at 12 bucks a treated gallon. Jon what does DD charge for a gal. of theirs?

Also I have recently discovered to my astonishment that not all buses have a water filter. If you are one of these you need to get one. Not only do they filter but they also contain that same precharge that is in the DD product and the pint shown above. It lasts quite a while so when doing oil changes you DO NOT replace these every time but check the antifreeze with the test strips and if it is getting low on the scale only then do you put on new water filters and it adds charge.

Here is the filter I just removed to show the part# fot those who do not have them.

Attachment 2091

Most probably know this but for those who do not, not using a no silicone product and not testing the antifreeze and making sure the charge is correct IMO it is probably the biggest one cause for premature engine failure, because many are just unaware.

Here is what the test strips are.

Attachment 2092

A truck supply house is probably the best place to go for these items, or DD for sure if that is convienient.

Joe, I do not remember what I paid last time I changed antifreeze. I have been using the DD antifreeze (not the 50/50 premix) and the DD conditioning filters. I changed anti freeze and filters (every six months for them) and still had to recore a radiator on the last bus. I am now using the "pay me now or pay me later" philosophy relative to coolant and conditioning filters.

Baldwin and other filter manufacturers make their water filters with no chemical charge and/or with 2, 4 or 8 units of pre-charge so that you can maintain the pH of your antifreeze without liquid charge.

Be sure you don't mix the DCA and DCE products when you change filters or add additional conditioner and as mentioned by Joe, automotive type antifreeze with a high silicon level are not recommended for use in heavy duty vehicle applications

I would never buy antifreeze premixed but do it myself by adding distilled water to the strait antifreeze gallon.

It is amazing to me that they can get people to pay the same price for 50/50 premixed verses the original concentrated stuff. Seems like a lot of cash for 2 quarts of water???????????????

Orren what is DCE?

Joe: Be sure to check label for shelf life expiration on the test strips. they are limited. The bottles I have had last one to two years then expire. May be like some medicines, just want you to trash the old so you will buy more new ones.

While reviewing some of the previous posts, I re read this post concerning using a vacuum device to remove and add antifreeze. I am sure this works, but it does seem a little magic. I am assuming pulling a vacuum on the cooling cavity, then the water flashes into a vapor when under vacuum and liquifies when returned to normal ambient pressure. Whew, am I digging to deep??!!@@

Has anyone else used one of these?

My wife says, 'just use the d#$% thing and see if it works". Sometime simpler is better.


Jon, if you are going to use this, please offer us feedback as to how it worked. I would sure simplify coolant changes.

Hector

Hector,

Jon's still working his way home from Pt St Lucie, it takes a long time at 62.5. He left Pt St Lucie this morning at 2:27 AM and I passed him on I-75 at Wildwood about noon today and he was fast asleep. He should be home by Sunday.:p

We left PSL yesterday morning, and after taking a nap in Chattanooga to avoid the nutty Knoxville rush hour demolition derby on I 40 we were having dinner in the Cracker Barrel 3 miles from home at 7:00 PM after filling the bus and the Hummer with fuel. It was 770 miles each way and I took on 214 gallons of fuel which included running the Webasto and generator. My Pro Driver said 7.34 mpg for the last 6000 miles.

When runnning with the King we kept the speed down low so he could keep pace when I was in the front. When running solo on the return there were occasions when I saw speeds approaching 64.76 mph. I think that is the fastest I have ever driven.

Bull, I witnessed him going 64.8 mph downhill thru the middle of Atlanta.

I am shocked! The King has mis-spoken. He led the entire way though Atlanta and for about 1/2 of the entire journey and I have no choice but to attempt to keep his LED tail lights in sight.

I am surprised he hasn't posted a story about what happened when I was in the lead, or at least claimed he has a story (which I intend to deny).

In an early post on this thread Jon posted info on a coolant vacuum replacement tool. Has anyone used one yet?

When returning from our recent Sevierville trip we stopped at Prevost Nashville for an LOF. I made a point of informing the tech that our bus has Texaco Extended Life Coolant (EC-1) installed and that it is not compatible with the normal green coolant. The result was that my information was either ignored or not understood, the system apparently was topped with green coolant, and SCA timed release filters were installed which is a no-no for extended life coolants. Am currently completing a CAT Level 2 (mail in) chemical analysis and anticipate having to evacuate and refill the system. To their credit, the Prevost, Nashville service department is in the loop and has assured me they will help resolve the issue.

The Texaco coolant is manufactured in compliance with Cat ELC specs and complete info on its use is shown on their information sheet. http://www.cat.com/cda/files/87058/7/elcfaq.pdf. The extended life coolant is a good product and is a virtually life-long coolant with a life expectancy of 600,000 miles.

I consider this just another lesson that work done by others on our busses needs to be double-checked. Once again I made an assumption that I was leaving this routine service in the hands of the experts. :confused:
In retrospect I should have checked the filters before we left Nashville

Brian,

What is a LOF?

I thought you were getting a all axle alignment. If you did, could you tell me if your bus was out of specs and if so did you notice a difference?

Dale,

Trucker talk for Lube, Oil, Filter change. Also, while at Prevost Craig their alignment, guy checked the steering and suspension for tightness. He showed me how the king pins/bushings were worn out and that they must be fixed before an alignment could be expected to last. He also verified the alignment numbers I was given when the new tires were installed in Pensacola were probably correct. The Prevost estimate for king pins was over $2500.00 lewbucks :eek:. Consequently I presently have the front wheels off of the bus at home and am about to disassemble the front end to do the job myself. Depending on whether the king pins and another alignment corrects the steer wandering I've been experiencing, I may elect to install the optional longer radius rods which will increase the caster angle. I will post the results as they occur. I will also change to an appropriate thread or start a new one to keep the thread cops happy.

Brian,

I hear that if you bury the old king pins in the yard they are quite the mole deterrent.

JDUB

JDUB,

Seriously I think Brian and Beverly want that whole Mole episode to be behind them. I'm sure these constant reminders aren't necessary.

Attachment 2809

mm

Brian, you should bury those pins upside down, so goes the tale.:cool::D

"I consider this just another lesson that work done by others on our busses needs to be double-checked. Once again I made an assumption that I was leaving this routine service in the hands of the experts.
In retrospect I should have checked the filters before we left Nashville"

Spoken like a true pilot who preflights his aircraft. However when you engage the services of experts, and you pay them a kingly sum there is a level of trust that should negate the need to double check their work. In fact, it is the management of the facility that needs a quality program in which they double check their own work because most of their work is buttoned up and hidden from view. We should not have to possess the same level of expertise that they have. It is just not our job.

We should schedule a high level Prevost representative to attend one of our next rallies for the express purpose of hearing what we are talking about, such as high pricing, poor worksmanship, frequent returns to have work corrected, and insensitivity to the economics of the work performed.

Brian,

Just curious here, what kind of mileage is on your coach would have to allow the king pin bushings to wear like that. Was there an obvious tire wear condition too? How about the other components (tie rod ends and drag link)?