COOLANT CHANGE

[Jon Wehrenberg]

The coolant change project is well under way. It is a huge time consumer.

But I am encouraged at what the end result will be. I am changing from Power Cool which requires SCAs to an EC-1 spec extended life coolant. While I would prefer to use the Detroit Diesel extended life product they only offer it in a 50/50 mix here in Knoxville which will not work for me as explained below. Instead I will use the CAT coolant and as in all extended life coolants it is an OAT (organic acid technology) and it is the standard everyone else meets. As it turns out the pricing is not far off what I can get an ELC for at Truck Pro. Concentrate is $21.48 a gallon and pre-mix is $11.55.

I am assuming my listed cooling system capacity of 24 gallons is correct. I have OTR and Webasto so in addition to the engine, my system also contains a large volume of coolant in the heat exchangers in the OTR as well as in the Webasto and the HW tank. I have no illusions about being able to drain the system without some serious disassembly and I am not about to do that.

So I drain what I can at the petcock at the base of the radiator or the lowest coolant pipe from the radiator. When I do that I can drain 15 gallons leaving 9 gallons spread amongst all the piping in the house and the OTR system and the HW tank heat exchanger plus the transmission intercooler.

The first step is to flush out as much of the old Power Cool as possible. So four times now I have drained 15 gallons from the system and refilled with fresh water. At the last drain the water was almost clear with a pink tinge. The EC-1 coolant can tolerate up to 10% SCA coolant so I am OK if I fill the system now, but I am first going to flush the radiator and also change a pair of hoses on the Webasto system that need to be replaced. After each drain I run the Webasto, the engine at high idle and the OTR heat system at the highest temperature setting. I think this has circulated the fresh water throughout the entire system so I am draining the old coolant as well as possible.

Changing the hoses will drain more of the house portion so on the next fresh water fill I will have almost completely removed the old coolant. With each drain and refill I added 15 gallons to 9 gallons of contaminated coolant (the kind with SCAs) so by the time I am ready to clean and flush the radiator I will have maybe a few quarts of coolant with SCAs spread throughout the 24 gallon system. Theoretically I can have 2.4 gallons of 50/50 mix of old coolant and still be OK.

I will flush the radiator tomorrow or the next day. When I do that I intend to shut off every system valve isolating the bus engine from the balance of the system. The reason for this is to minimize the possibility I will contaminate the whole system with the harsh chemicals used to flush the radiator. I will flush that out at least three or four times to make every effort no radiator flush chemicals are in the system to contaminate the new coolant.

Assuming my system will retain 9 gallons just by using the drains mentioned previously, I will add nine gallons of concentrate so I have a 50/50 mix, and then top off the system with 6 more gallons of premix.

I have some things I am fortunate to have going for me. First, Knox County TN has convenience centers to bring all wastes, including anti-freeze, old oil, tires, etc. I have a lot of gallons of progressively less concentrated coolant to bring to the convenience centers. They don't charge so I have no fees associated with the drained coolant. (I save old 5 gallon pails from everything including oil, gear lube, and deck sealer to carry my old oil and anti-freeze to the convenience centers)

I also have a place to work that is easy for me to do this without spilling anything so I don't have to worry about my dogs or any animals being endangered by the old coolant with is poisonous to animals.

My cost apart from my time is going to be $270 or thereabouts and with any luck I will not have to do anything ()other than re-charge the coolant in 3 years), for the next 6 years.

I will do the same to the generator shortly so I only have to carry a gallon or two of the concentrate to deal with either cooling system.

[rfoster]

Damn, I thought I really did something when I changed my fuel filters this past weekend. And oil & oil filters. And power coolant can.

[travelite]

Jon,

Have you considered blowing the Webasto and chassis heater lines free of coolant using a regulated air supply? Also, after you're done it may be worthwhile to drain a sample and have it tested by CAT to be certain that the OAT is as prescribed. I understand that test strips are also now available.

[GDeen]

Between the remodel and this, you making me exhausted.....gunning to regain that A1 moniker are we??

[Jon Wehrenberg]

Jon,

Have you considered blowing the Webasto and chassis heater lines free of coolant using a regulated air supply? Also, after you're done it may be worthwhile to drain a sample and have it tested by CAT to be certain that the OAT is as prescribed. I understand that test strips are also now available.

I considered a number of options but one impediment to clearing both the Webasto and OTR coolant lines is both have solenoid valves. If I broke the lines at the valves I may find myself with more problems when it comes to burping and filling the system. By the time I get through flushing the radiator, flushing that portion of the system, then re-opening the entire system and doing another flush or two I seriously doubt I will have enough of the Power Cool remaining to talk about.

I barely see a pink tinge to the drained water now so I think I will have almost no contamination.

Two of the short sections of hose I have to replace are in the supply and return line for the forward Webasto units so whether I want to or not those will be drained. I previously drained the system aggressively and I was burping it for several hundred miles. I am not looking forward to what it will take to do that again just for the forward Webastos. Getting lazy.

[travelite]

Jon,

I recently used one of these when changing the coolant on my genny:
http://buy1.snapon.com/catalog/item....group_ID=12500

I haven't yet used it on the S-60, but on the genny it worked well. No spills, air pockets, or overheating. When I pulled the vacuum, I found that my radiator drain petcock was leaking a bit; if it doesn't hold a vacuum there's probably a leak somewhere. Once a good vacuum was created, I put the fill tube in a 5 gal bucket of premix and opened the fill valve. Really cool to watch the fluid being sucked into the coolant system. Very fast.

[Jon Wehrenberg]

I have one and I have used it quite a bit. I think my end result and plan will work well because I use the Webasto to do a lot of the purging as I have done in the past. Once the Webasto cirulating pump starts circulating coolant I just keep adding to the header as necessary. Then I run the engine until the thermostat opens. If I cannot get it hot enough on high idle I just back up my driveway twice. It is steep enough to put a big load on the engine.

It takes forever to pull a vaccum on the bus system.

[travelite]

Jon,

To warm up the engine so the thermostat opens, there's nothing wrong with applying the brakes, putting the transmission in Drive, and bringing the revs up to 800 to 1000 rpm. Have you ever seen Prevost Car do a stall test on a new transmission?

[Jon Wehrenberg]

You haven't seen my driveway. Believe me. Two trips back up it and I'm done.

[travelite]

I once saw Prevost Car do a stall test on a newly installed Allison transmission. The tech applied the brakes, put it in drive, and ran the engine up against it's governor and held it there for what seemed like an eternity. The transmission grunting, the brakes holding it back, the engine screaming, quite a sight.