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Topic: Coolant leak in dash heater core?? (Read 545 times) previous topic - next topic

Coolant leak in dash heater core??

I always smell the unmistakable odor of antifreeze when the dash heater is on. I do not see any evidence of a leak. Cummins Northwest tested the cooling system by pressurizing the system and found no evidence of a leak.  The induced pressure did not drop during the test period.  I am thinking that I should disassemble the heater and look for evidence of a small leak (small leaks will become big leaks). Has anyone disassembled their heater to repair or replace the core and if so, is it a difficult procedure? It looks like a daunting task but I might do it myself with encouragement from someone who has been there. Comments will be appreciated.
Gary
Gary Vanhoff
1998 U320
3600 WTFE
Build No. 5342
2007 HHR Toad
Spokane Valley, Washington

Re: Coolant leak in dash heater core??

Reply #1 –
We found our heater core leak by permanently hanging a plastic container so the dash air conditioner evaporator condensate rubber drain hose empties into the container.  When the fluid collection measured freeze protection using an inexpensive tester, we knew we had a heater core leak.  Plain water collected would be normal condensate.
Condensate drain on our coach is just to the left of the generator when looking in toward the rear of the coach with the generator door open.
We then put ball valves on the heater hoses (to the dash and from the dash) at the street side of our Cummins engine.  We closed the new ball valves and drove for several summer months until we could change out the heater core.
The center of the dash comes out after removing several wood screws into the floor and into the adjoining dash sections.  This exposes the metal box housing the heater core & air conditioner evaporator coil.  The air conditioner pressure hoses had to be disconnected and refilled with refrigerant after the heater core was replaced.

Re: Coolant leak in dash heater core??

Reply #2 –
Gary,

Here is a link to a thread that may have some info that will help you out.  We were talking about a U-270 but a lot will apply as the dash comes apart the same. With you having a U-320 the big difference is you have a Aqua Hot heater core that is hid in there. Have you been having to add more antifreeze to your A/H unit lately? If so this may be the reason a pressure test on the engine coolant system didn't show up a leak.

Replace Heater Core 98 U270

Pamela & Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Coolant leak in dash heater core??

Reply #3 –
Quote
The air conditioner pressure hoses had to be disconnected and refilled with refrigerant after the heater core was replaced.
More...Like Quote
Barry, does yours have a split system (separate heater core and A/C evaporator) or a combined system (heater core and A/C evaporator in one unit)? I just ordered one from FOT and Billy Jack told me ours is a split system. I was surprised, as I have never had a vehicle that had the units combined. I am hoping not to have to disconnect and A/C hoses to do the replacement!
Don
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Don & Tys
1999 U270 3602 WTFE #5402
Xtreme Stage 1 w/Headlight, Step Conversion, etc.
2009 Honda Fit Sport with Navi
Freedom is NOT "just another word for nothing left to lose"... with apologies to Kris Kristofferson

Re: Coolant leak in dash heater core??

Reply #4 –
Don, our dash had separate heater core and A/C evaporator.  I was not aware of combined units, although autos may have such an item for efficiency.
There are heater hoses and coolant lines visible on bottom left side of our dash circuit breaker panel.

Re: Coolant leak in dash heater core??

Reply #5 –
When I did ours, I didn't have to disconnect AC hoses.  Pinched heater hoses, no leaking (but some drips).

Heater core replacement

Dave and Nancy
1999/2013 U270 36' Xtreme
Motorcade # 16774
2013 Subaru Outback
KD0NIM

Re: Coolant leak in dash heater core??

Reply #6 –
Thanks Dave, that is helpful to know! I received the heater core from FOT today, wondering if I should maybe pressure test it before I put it in or trust that it will be good to go ::) . It seems that it isn't that tough a job, but tedious to be sure. For sure a good idea to take a few pictures as I go to supplement my memory. Thanks for the link to your replacement. I am hoping I will find my AGS module when I tear into the dash!
Don

Quote from: Dave Katsuki –
When I did ours, I didn't have to disconnect AC hoses.  Pinched heater hoses, no leaking (but some drips).

Heater core replacement


The selected media item is not currently available.
Don & Tys
1999 U270 3602 WTFE #5402
Xtreme Stage 1 w/Headlight, Step Conversion, etc.
2009 Honda Fit Sport with Navi
Freedom is NOT "just another word for nothing left to lose"... with apologies to Kris Kristofferson