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Cat 272c heater problem

woodsinaz

Member
Joined
Jan 4, 2019
Messages
5
Location
Az
Hey guys. new guy to the forum but have read alot and seems to be some really great folks here. I have a 272c red676 that had no heat. it has sat for a long time and the electric valve was bad. i replace the heater core and the valve and still have no heat. both heater hose remain cold even when the engine is warm, like there is no flow. anyone have any thoughts or ideas? thanks very much in advance for any help you guys can give me.
 

woodsinaz

Member
Joined
Jan 4, 2019
Messages
5
Location
Az
Possibly.... That's kind of what I was asking.... Will a stuck t-stat do that to a heater? My plan is to pull it in the morning and see. Thanks
 

Steve Frazier

Founder
Staff member
Joined
Oct 30, 2003
Messages
6,599
Location
LaGrangeville, N.Y.
The thermostat controls the temperature of the engine coolant, if it were stuck closed you'd risk overheating, open and the engine would take a long time to warm up. Regardless the coolant to the heater core should be the same temp as that in the engine. You stated the heater hoses are cold but engine is warm. Have you felt the radiator hoses to confirm this or assuming it? If the engine is indeed warm I don't think the engine thermostat is going to have a bearing on your problem, the heater hoses should be on the engine side of the thermostat.

Have you ever had heat from the machine or did you inherit an existing problem?

It sounds like there's a blockage somewhere. Have you verified that the actuator valve is getting power from the switch? Is it grounded properly? Any kinks in the hoses that would prevent flow? I had an instance once where the fitting on the block that the heater hose connected to clogged with debris on an old truck. Your going to have to start tracing the flow and verify it has a clear path.
 

DIYDAVE

Senior Member
Joined
Feb 18, 2007
Messages
2,409
Location
MD
Also to think about, sometimes debris will gum up the bypass hole, in the t-stat, or jam against heater control valve. Had one, once, that somebody had over applied red silicone gasket maker, and pieces of it were in the t-stat, valve, and heater core...:eek:
 

woodsinaz

Member
Joined
Jan 4, 2019
Messages
5
Location
Az
Thanks guys. I have located the problem. It was an electrical issue to the heater valve. The valve appeared to be open about 1/4 of the way and was not getting power from the switch to open fully. Thanks for the replies and ideas.
 

woodsinaz

Member
Joined
Jan 4, 2019
Messages
5
Location
Az
Well... It was also 2.5 gallons low on coolant after just coming back from the dealer for a complete svc. Sorry, should have also mentioned that minor detail... Haha
 

Mobiltech

Senior Member
Joined
Jan 14, 2014
Messages
1,680
Location
Sask.
Occupation
Self employed Heavy duty mechanic
Wow. It only holds 3.5 gallons. Probably not even enough to circulate. Hope it wasn’t run too long.
 
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