Workhorse P32 8.1 AntiFreeze Should I be worried

[RVtomtom]

I have a P32 chassis with the 8.1 which I got about 3 months ago. I have clocked about 2,000 miles to the original 30,000 miles so far but have had to add almost 1/2 gallon of antifreeze to the reservoir. Seems a bit much considering I rarely need to do this with my car. Is this something I should worry about?

Tom

[edgray]

TOM: Hopefully the article pasted below (issued by WCC) will help you understand the system. IF, after verifying that the Radiator is completely full, you continue to need additional fluid, THEN you'll want to find the source of the leak. Good luck!

Note: This is the second in a series of Workhorse Technical Reports with information that Workhorse considers most important in helping motor home owners avoid potential problems and maximize the economy, safety and enjoyment of their driving experience.

Key maintenance check: How the motor home

coolant overflow reservoir works

Coolant overflow reservoirs were added to vehicles to make cross flow radiators more efficient. This is done by assuring that the radiator is full to the fill cap at all times during operation. To ensure the most efficient radiator operation and prevent any potential cooling problems, the operator should understand how the system works and see that it is regularly checked. Here is a brief explanation of the radiator-reservoir system and what to look for in checking proper fluid levels.

Coolant movement from radiator to reservoir
Coolant flow from the radiator to reservoir occurs when the coolant expands from heat. The expanding fluid opens the radiator spring loaded cap and flow occurs in a tube from radiator to reservoir. (The overflow tank is often called an EXPANSION tank.) This fluid movement occurs due to a pressure build up from expanding coolant. The pressure is NOT the result of boiling coolant.

If the radiator is low, the expanding coolant will build pressure in the radiator, but often insufficient pressure to lift the pressure cap. (Air is compressible—coolant is not.) If pressure exceeds the 15 psi cap, only air and not coolant will escape to the reservoir. Thus, the recovery system will not work when radiator level is low enough such that expanding coolant does not empty the trapped air from the radiator.

Coolant movement from the reservoir to radiator
When the coolant in the radiator cools, it shrinks in volume and creates a vacuum in the radiator. This vacuum pulls coolant from the reservoir back into the radiator through a one-way check valve in the cap.

If the radiator level is low, the normal pressure produced from normal engine operation will decrease and a sufficient vacuum will not be produced to pull the coolant from the reservoir.

Conclusions
* Coolant recovery system is inoperative when radiator is sufficiently low on coolant.
* Coolant tank can be at full mark at the same time that radiator is low enough to cause overheating.
* If an operator fills an empty reservoir, he must check radiator level to assure that it is full.
* If reservoir level does NOT CHANGE between hot and cold, radiator level is low.

Recommendations
* Radiator level should be checked (by removing cap) at every oil change (Caution: Open only when cold. Contents under pressure.)
* Reservoir level should be checked for HOT and COLD level at every fueling. (Cold level should be checked before starting a day's trip before start up.)
* Radiator level (as well as all fluid levels) should be checked before and after storage of one month or more.

[jeepfreak]

Don't know what year your chassis is but some of us have found a threaded plug on the drivers side head , I think its between the #3 and #5 exhaust ports and that plug was loose enough to leak anti-freeze but would not leave a spot as it would evaporate due to the heat. I was able to tighten mine at least 2 to 3 turns. Hope this helps.

[cannon man]

also on the other side is the temp sender. mine was loose n leaking on starter. hope this helps too.

[DriVer]

Quote:

Originally Posted by RVtomtom I have a P32 chassis with the 8.1 which I got about 3 months ago. I have clocked about 2,000 miles to the original 30,000 miles so far but have had to add almost 1/2 gallon of antifreeze to the reservoir. Seems a bit much considering I rarely need to do this with my car. Is this something I should worry about?

Tom, I have had a slow leak that never did drip on the ground. The engine would boil off the coolant before it showed up on the ground. Check the plugs as suggested for leakage and give them a little bit of a turn if they're loose. If your engine is tight like mine presently is you should be able to maintain the same level in your expansion tank trip after trip.

[RVtomtom]

Checked plugs etc all ok. I think the rad level was low cause now the levels in the resevoir show normal both hot and cold. I will have it checked out when I do my next oil/lub pit stop. TOM