Losing coolant out of reservoir

[WN8HGZ]

Motor home is winnebago, meridian itasca 34 foot, 2005, model is ikp34h, freightliner x-line chassis ,engine is c7 350 cat: 23000. Miles on engine and system. Have been to two cat authorized service centers. No joy there warranty runs out june 2010
problem definition: Have lost half of my antifreeze out the reservoir through the overflow tube. Radiator cap is a 16 lb pressure, most cats use a 10 or 12 lb cap. Have looked for water in oil--no water in oil. Replaced the cap with a new 16 lb and no fluid loss for about 2700 miles and then lost half the antifreeze again after driving 500 miles..static test of the cap shows that it releases pressure and 16 lbs. Havent the slightest idea what to do. Have no satisfaction from winnebago, freightliner, or cat service reps. Cf 9898599374 any help would be appreciated.

[Pusherman]

Check the Surge Tank for leaks. This is the reservoir tank on top of the radiator. If it looks crazed, the tank itself may be leaking. It's pretty common on these units. Solution is to replace the tank.

Evidence may be streaks down the rear cap of the motorhome behind the radiator. A good RV shop should be able to diagnose it.

P.S. This is most likely a FL warranty issue, not CAT, as FL builds the chassis, and CAT provides the engine (not the radiator). Unfortunately, your FL warranty is 3 yrs/36K miles. I doubt if you will get it repaired under the OEM's warranties.

[J Walker]

For all except leaking of coolant into the exhaust system, you should see lots of coolant leaking and know the source. Therefore check to see if there is coolant in the exhaust. That will be a bad thing to find and I hope it is not the case.

[ischua]

How much antifreeze are you loosing ? Half the system or half the reservoir tank? You might want to have someone check the cylinder pressures ASAP. A head gasket leak will blow gasses into the cooling system and push the antifreeze out the overflow tube . Increasing the cap pressure might lead to ruptures in hoses or radiator and cause more damage

[J Walker]

Another simple and harmless possibility is that the reservoir, which sounds like a surge tank, is purging air from the cooling system and doing its job. It can take a really long time to get the air out of the system. I can go 5,000 miles before mine is purged. Then my overflow tank is as stable as can be. I did worry about it when I first saw it.

[WN8HGZ]

Quote:

Originally Posted by wn8hgz motor home is winnebago, meridian itasca 34 foot, 2005, model is ikp34h, freightliner x-line chassis ,engine is c7 350 cat: 23000. Miles on engine and system. Have been to two cat authorized service centers. No joy there warranty runs out june 2010 problem definition: Have lost half of my antifreeze out the reservoir through the overflow tube. Radiator cap is a 16 lb pressure, most cats use a 10 or 12 lb cap. Have looked for water in oil--no water in oil. Replaced the cap with a new 16 lb and no fluid loss for about 2700 miles and then lost half the antifreeze again after driving 500 miles..static test of the cap shows that it releases pressure and 16 lbs. Havent the slightest idea what to do. Have no satisfaction from winnebago, freightliner, or cat service reps. Cf 9898599374 any help would be appreciated.

i lose half of the coolant from the reservoir. My plan is to pur a small bottle under the overlow and varify that the coolant is comming from the overflow tube. Have had the motor home on a dynmometer and there was no fluid loss. Even took off the reservoir for inspection and no crazying.
Thanks all for helping me the service centers have not done their job. Thanks all i will let you know what happens.

[hondo122]

Are you getting a low coolant message? Is the level below the add line on the reservoir? Are you checking right after shutdown or after everything has cooled? It is an expansion tank to allow for this, if you don't add more does level get lower?

[Mike Canter]

I had this problem and finally had to put a small amount of special fluorescent dye in the anti-freeze and use a UV light to find the leak. I found the leak right away and the mechanic that is working or your coach should consider this. My leak was a worse case scenario and was leaking out the head gasket down the side of the block. It was a real small amount so it ddn't pool on the ground under the MH. I hope that your problem is an easy one to fix.

[wdbates]

Did you check/change thermostat? I know its most likely the first thing that was checked but just wanted to mention it...