Coolant/Antifreeze

[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

[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