So I removed the heat core cover and noticed a fair amount of rust around the valve and the connections.









I guess it leaked at one point. I'm redoing the floors/carpets now and I don't want a leak to happen after all that work. Should I replace just in case?

Doesn't look like the core itself is leaking - just the pipe connections. Since it's not that expensive, I'm replacing mine while my console is out. Those pipes are looking pretty crusty too so at the very least replace them, the gasket fittings and the valve. A sensible "while you're there" project.

Had a leak about two months ago at my heater valve. The valve and pipes were not nearly as rusted as yours are in the pictures. However, when I pulled up the carpet to inspect i did see a rust spot forming. The heater core looks like it is in good condition. There are rubber gaskets to form a good seal to the heater pipes and the valve. If that pipe is overtightened on the core it will do two things. One, leak, as it will deform the rubber seal. Two, strip the thread on the heater core itself. Check the thread on the core. if you have to order new pipes and valve than order the rubber gaskets as well. Looks like you have the floor pulled up in the pick so hopefully no floor rust from the leak. They sell new pipes specifically bent to accomadate a replacement valve as the original valve is not available any longer. i think the new valve is an X 1/9 valve. As long as you order the pipes, valve and rubber gaskets from the same vendor they will hook you up and should align to the holes in your firewall.

One last thing you will find on heater valve posts. It is worth the extra 15 minutes to take the passenger seat out so you can see what your doing under there. I could not tell from the pick if you already pulled the seat.

Good luck. Ray

I'm thinking I'll remove the pipes and valve, clean them up and see what I've got. If the components look OK I'll treat with paint/POR-15 and replace the gaskets.

Not sure the history of this car. Some components are rusty where I didn't think rust would be - eg. on the heater core pipes, the FI computer (I think that's what it is... under the dash on the passenger side), some of the steering components inside the car between steering wheel and firewall. I'm sure each of these cars has quite a history... Maybe there was a lot of water sitting in the floor that caused high levels of humidity in car for extended periods of time I guess??? Then again it's 31+ years old so what do I expect?

I assume I have to drain the coolant before I remove heater core valve otherwise I'll have a big mess in the car. What's the most complete way to do this? Drain the rad and maybe an engine block drain?

While you have it out of the car, take it to a radiator shop and have it cleaned and pressure tested. Much cheaper to go this route than to replace with a new one, but will provide piece of mind that you will be heater core "leak free" for a few years.
Mine looked much worse than yours, cost $35.00 to have it cleaned and repaired where it had developed a leak.

kmac33 wrote:While you have it out of the car, take it to a radiator shop and have it cleaned and pressure tested. Much cheaper to go this route than to replace with a new one, but will provide piece of mind that you will be heater core "leak free" for a few years.
Mine looked much worse than yours, cost $35.00 to have it cleaned and repaired where it had developed a leak.

Sounds like a plan. Thanks.

Took out the heater core, valve and pipes. It was best to leave everything together, unhook the pipes on the engine side of the firewall and just lower the whole thing. Valve is shot (plugged with gunk!) for sure. But the heater core looks great (maybe it was already done in the past?).



So I think I'm looking at new valve and gaskets. Also once I cleaned the pipes with steel wool they looked good as well and weren't plugged at all (not shown in above picture). I'll reassemble everything and pressure test with a garden hose.

your old pipes will most likely not work with the geometry of the new valve for the firewall holes.

Yes the new valves require you to bend the short pipe a bit so it winds up pointing out the hole in the firewall properly. Or you can get the remade new pipe that has the correct bends for around $50.00 with shipping. I just ordered a new heater core, valve and pipes as the used ones I had were very thin and rusty on the edges and I don't trust used heater cores that show green scale . You heater core looks in good shape though.

And for the gaskets I need 3 new ones, 2 for where the pipes go into the heater core and 1 for where the pipe goes into the valve. So I use this gasket for all 3?

http://www.autoricambi.us/product/HE6-0 ... er-Gasket/

I didn't see a different listing for the gasket that goes into the heater valve.

Yep, Same gasket for all three.

SLOSpider wrote:Yes the new valves require you to bend the short pipe a bit so it winds up pointing out the hole in the firewall properly. Or you can get the remade new pipe that has the correct bends for around $50.00 with shipping. I just ordered a new heater core, valve and pipes as the used ones I had were very thin and rusty on the edges and I don't trust used heater cores that show green scale . You heater core looks in good shape though.

SLOSpider,
Where can I get the new pipe with the proper angle (ie. https://www.autoricambi.us/product/HE6- ... ater-Tube/ )? I checked http://www.autoricambi.us/ (where I'm getting the valve and gaskets) but they don't have them in stock. Not sure how long it will take until they get them.

Richard, You may want to check with Mark, he has the fitted heater pipe as well.

Sorry I must have bought the last one But yes Mark Allison Automotive has them for sale too.

Actually I emailed autocambri and Csaba responded that they did have them in stock and it was just a clerical/online error. So I ended up ordering all pipes, gaskets and valve just to be sure. Ordered them this morning and they are already being shipped! Awesome.