Two cooling system questions

[bruceh]

I have been having heating issues on my coach and am about to flush the cooling system, replace the radiator cap and the thermostat.

Question #1

I have read on this forum that the expansion tank is supposed to fill when hot and drain back to the radiator when cold. Mine does not do this. Will my proposed action fix this or is there something else that I need to do?

Question #2

I have read on this forum that hoses should be replaced after 10 years. My 2001 coach is at 10 years. How solid is this advice, has anybody done this? If I am going to do this, it makes sense to do it all at once.

Thanks for the shared expertise,

[wildtoad]

Q1: How do you know? Is the radiator overheating and spewing coolant? The expanding coolant has to go somewhere? Perhaps the tube from the radiator fill to the overflow tank is clogged.

Q2: I do think the hoses need to be checked annually to see if they are deteriorating and replaced if needed. Same as belts. 10 years is a long time for rubber parts to last so it may be a good preventive maintenance procedure to just replace them.

[bruceh]

[QUOTE=wildtoad;901593]Q1: How do you know? Is the radiator overheating and spewing coolant? The expanding coolant has to go somewhere? Perhaps the tube from the radiator fill to the overflow tank is clogged.

QUOTE]

Observation, I look at the tank when hot and it is full, I look when it is cold and it is still full. According to earliers posts in this forum, this is not correct.

[edgray]

Quote:

Originally Posted by bruceh I have been having heating issues on my coach and am about to flush the cooling system, replace the radiator cap and the thermostat. Question #1 I have read on this forum that the expansion tank is supposed to fill when hot and drain back to the radiator when cold. Mine does not do this. Will my proposed action fix this or is there something else that I need to do? Question #2 I have read on this forum that hoses should be replaced after 10 years. My 2001 coach is at 10 years. How solid is this advice, has anybody done this? If I am going to do this, it makes sense to do it all at once. Thanks for the shared expertise,

bruceh: perhaps reading this: How The Motorhome Coolant Overflow Reservoir Works will help you understand the system better. There "should be" noticible difference in the level of the tank from hot (immediately after shutting off the motor the level should begin to rise) to cold "if" the radiator is full to be with. If the radiator is low enough....this may not happen. Open the radiator cap when it is COLD....ONLY... to see if it is full.

Regarding hose replacement, I would at least replace the TOP hose if i were changing out the T-stat and cap. IMO, the lower hose is less likely to fail because it is on the suction side, and is exposed to cooler fluid than the top hose, but for peace of mind you can change it also, if you find one. Good luck
Ed

[DriVer]

I kept opening up my radiator cap and making sure that the coolant level was all the way up to the top. Add to fill the the radiator. Do so cold and then if you can do so, after the T-Stat opens but be careful. The fluid level will plunge when the thermostat opens. HOT stuff. The recovery bottle should work as advertised with the Hot and Cold levels being where they should.

A process called burping helps .. read the article that ED suggested.

[iRV4FUN]

Quote:

Originally Posted by bruceh I have been having heating issues on my coach ... Will my proposed action fix this or is there something else that I need to do?

First, try to identify what the heating issue is before pouring six gallons of fluid into it.

I had a fluid loss problem and had a truck mechanic do a pressure test that showed no leaks. Somebody on this Forum suggested checking my hoses. Sure enough my bottom hose needed to be tighter.

Burping the 8.1L system and making sure the new rad cap is in the correct alignment may help.


Good Luck!

Does anyone know what the “Normal” temperature range (via a scan tool not the IP) is for the 8.1L?

[DriVer]

Quote:

Originally Posted by iRV4FUN Does anyone know what the “Normal” temperature range (via a scan tool not the IP) is for the 8.1L?

"Normal" is a range in between 195°F to 225°F just before the needle begins moving off the peg.