Heater core test.

[gsitts]

hi everyone. I haven't posted in about 4 years but just got another discovery 1
It's a 1995 with 80 k on the clock that looks to be in pretty good shape overall.
Almost the first thing I noticed was the heat control valve is missing and the hose looped back at the engine connections so I assumed a bad heater core , I have no info on this
"repair" so I decided to check the heater core myself. Here is what I did... I made up some garden hose connections to pressurize the core but realizing the higher pressure might just pop it I also connected the outlet to another hose which I connected to a lawn sprinkler in the vard. This lowered the pressure to about 15 psi and also allowed the flow of water thru the core. I ran this test for about 45 minutes while looking for any water under the center console and the foot wells. I'm happy to report the core seems to be in good shape. I also noticed the back side of the carpets have never been wet so I guess
I'll get a heater control valve and see what happens. This story isn't here just because I'm long winded I'd like any input regarding what I might have missed etc.
I'm glad to be back
Gordon

 

[NikeCheck246]

I would be very wary...I don't know many people that forego their heat and loop off their cooling system at the heater core for Saturday afternoon fun. And why do you need the heater control valve? That will just stop the flow of coolant if you close it and you REALLY need coolant to circulate. If it leaks, you are going to need to loop it again.

 

[mbrummal]

if that valve was leaking originally the owner might not have wanted to replace it and just bypassed it entirely. you never know.

 

[ptschram]

Did yours have the valve? There were VERY few '95 Discos that had the water control valve. They were ubiquitous on most '94s, but I have a '94 in the shop without the valve.

Jeremy-the water valve had a provision to return flow to the engine if the heater core were isolated.

 

[gsitts]

I have to assume the valve was there at one time but I have no first hand knowledge.
I'm working off the premise Mason offered... Bad valve Primarily because the carpet is so clean on the back side. I see no sign of any leaks anywhere. Time will tell I just ordered a valve from Will.

 

[German Gr?ner]

I think there wasn't really a valve.
Only in very old 94 Discos could you find it. If You turn both temperature controls to full cool, you can feel the sound from the electrical switchs controlling this valve.
But in just all Discos this switchs are not present.
The "new" design was heater core with coolant circulating everytime.
The temperature controls only allow more or less air to pass thru the core.
Some people do this bypass in order to get cool weather in summer, when there is a missing or out of order control flapper, producing permanent heat air flow.
May be this can be your problem. If so, you can enjoy your heater next winter.

Regards

 

[gsitts]

That is good info I'll know more after I try to put it in. I will need a heater this winter even though I live in La. We need them for the windshield

 

[NikeCheck246]

Did yours have the valve? There were VERY few '95 Discos that had the water control valve. They were ubiquitous on most '94s, but I have a '94 in the shop without the valve.

Jeremy-the water valve had a provision to return flow to the engine if the heater core were isolated.

aha, i understand...i have not experienced this valve yet, not many discos in this area that old. thanks pt!

 

[JohnB]

Reminds me of my old 62 sprite. Those Brits are stuborn. Its been almost 25 years but I think it(62 sprite Flinstone rig)had a knob almost like what you connect your garden hose to. I think it was even brass. It leaked and broke.