heater core replacement

[rja]

have noticed a kit that includes a heater core (aftermarket) and some kinda valve that either routes coolant thru the core or sends it onto the intake manifold (but not both at the same time as i understand it). says it uses the oe control cable and i was wondering if anyone here has used it; is using it; or has any thoughts on it. my car is due a replacement and i live in a fairly hot climate and think this little engine deserves all the cooling it can get. what say ye? thanx.

[LIQUIDLOUNGE]

its a time consuming job, but doesn't take a great deal of mechanical acumen. If you have the $$$, buy the stainless heater core pipes from Allisons, it makes retrofitting the new valve alot easier. Like alot of things on these older cars, you go to fix one thing and you find a few other things that need to be addressed.

[azruss]

hard to evaluate without knowing exactly what you are looking at. I would stick with one of the fiat vendors as there are some eccentricities about the system. all the valve does in open and close the coolant flow thru the heater core. the original designs dont exist any more and the current choice is the 850 type which the geometry doesnt match, so the tubes dont go out the firewall in the right spot. Many of us have modified the tubing to get it to the right place. Mark Allision now has a valve that has those mods. Dont know if anyone has tried his or not. there are different core thicknesses depending on the year.

[LIQUIDLOUNGE]

I have used Allisons pipes, and felt it made the job quite a bit easier. If money is an issue, I would just run the heater hose through the firewall before trying to bend/modify the existing pipe(s).

[rja]

the heater core was bypassed by a po. i can still see the pipes sticking thru the firewall. is there no way to replace the core, using the same pipes and control valve set up like it is? or maybe get the core repaired and re-installl it? i feel sure it is all oe as just about everything else on the car seems to be. '74 124 sport 1800.

[donerehart]

I bypassed my heater core two years ago, and just last month installed a new heater core from Csaba and Mark's stainless heater core pipes...and re-hooked everything up. It is nice having some heat options on chili days now... It is a simple, but time consuming job...center console needs to come out...as always I found some things broken that I had to fix along the way, but now I am hoping things are back for a while.
Hope that helps some...
Don

[dmwhiteoak]

Along with the heater core I would also replace the control valve. I haven't had to change my core but have had it tore down far enough to do it. I have changed the control valve and it was fun.

[azruss]

usually it is the valve leaking that causes owners to bypass the heater. If the valve is still good, you can use it with a new core. If the valve is good then you are one lucky SOB and better go buy a lottery ticket

[FiatBen]

Have to agree with Azruss. Typically a bypassed core is signs of a failed valve, which is a pain in the butt. But, don't guess it would hurt to replace both as long as you have the center console torn out.

I would think it wouldn't be too hard to rig up a bypass under the hood and manually operate it seasonally. Certainly has to be easier than something with a cable thru the firewall and all. IMO

[donerehart]

I agree...didn't mention that in my post...also replaced the valve...you have it all apart...it is time to do what is needed...

[rja]

got the core out this afternoon. found a coupla leaks in it w/20 psi air press. did not see the valve leaking. how do these valves fail? diminished flow thru the valve, or do they start leaking externally? took the core and valve to the radiator shop to see if they could fix it. we'll know thursday. gonna try to make my own gaskets for the valve and pipes. have some eighth and sixteenth garlock mat'l. and some eighth rubberized. which do i use? looks like a pretty easy one to fab up. also thinking about a bypass line w/an inline valve to keep flow going in the summer when the heater valve is closed. what do you think of that idea?

[vandor]

A friend has been experimenting with the bypass valve, and he has a lot of hours into the conversion. Apparently a lot of those valves do not completely shut off the flow in either direction, since on newer cars that is not critical. He is using a vacuum activated valve, which adds even more hoses.

You can buy a new heaer core ($99 for an exact fit replacement), a valve, and a new valve to firewall tube, assemble them on the bench, and bolt them in.

[So Cal Mark]

letting the heater sit for long periods without any flow isn't a good idea. Even in the summer, I'll open the valve in the morning for a few minutes to get some circulation

[rja]

thank you guys; both your points are well taken. the guy at the rad shop works on all my "toys" and it's always reasonable. i'll be no worse off even if it leaks again. the job really wasn't that bad.(still have to refit it though, huh) some of the stuff i have to do to that '76 austin mini is just torturous! another fun ride, tho.

[azruss]

leaking heater valve is responsible for a lot of passenger floor rust issues. It gets into the seams and runs around the exterior of the sound padding and starts eating metal away. these valves leak to the outside from an internal seal. I have always hated this design and found them to leak on a whim. The original 124 valve was more reliable. Others here have reported the opposite.