colin_barnes

Hey Guys,

On my '83, there are a series of heater hoses on the passenger side of the engine. There is also a T-shaped valve/conduit that connects one hose going to the front of the engine horizontally, one hose going to the firewall horizontally and one hose going to the firewall vertically. That piece on my car is plastic. It is leaking. I need to replace it. Is it a valve or is it just a T-shaped coupler that is open inside? Do I have to replace it with another plastic T from the dealer??

Thanks,

Colin

jfairladyz

I dont think thats a factory piece. On both of my cars they're metal, not plastic. As far as whether its valve or not, those should just be open. Coolant constantly flows through the heater hoses, even when it's cold.

icice9

thats the heater valve.. mine is leaking too but its a P.I.A to replace. plus they want $100 for that valve at the dealer and thats pretty much the only place to get it....

jfairladyz

Are we talking on the engine side of the firewall or the passenger compartment of the firewall? Cause I thought we were talking inside the engine compartment Maybe that's why I was thinking metal pieces and they're not what you're talking about.

jmmorriso

Ok, Just went through this onmy 81 and had everything apart. The Tee fitting on the engine sideof the firewall appears to be a check valve of some sort. I thinkit is set up to divert coolant into the heater core and not to the bypass on the motor when the heater control valve is open. As for the heater control valve itself, onmy 81 na manual A/C. I bypassed the SOB. Take the glovebox and lower dash panels off, take the blower motor and AC evaporator off, remove the heater control valve, and all hoses. Put the valve in a vise, taking care not to damage the mechanics of the valve, get a screwdriver and hammer, push two or three of the tabs on the water end of the valve straight, fish the clippy dookickey off, and remove water side of the valve. Reinstall mechanics ov valve onto car. Oh, I forgot, before you do all this go to a good parts store, get a 5/8" heater hose coupler, and a heater hose that makes a U bend, mine had a goodyear part# on it,but its nowinthe car... After the mechanics of the valve are in place, cut and fit the new hose and adapter to go from the heater hose to the heater core. Nowis also a good time to replace the heater hoses to you dont get any more leaks on your carpet. As for the tee valve, Id try to find a used replacement, a regular pipe tee and some fittings, or find a way to eliminate it. From what Ive seen, the pipe fittings on the blocks on these cars is just regular pipe thread, so eliminating that two headed beast on the back of the block will help If you eliminate the tee valve, i would imagine you would have to eliminate the heater control valve as well. so coolant is always bypassing the radiator to eliminate air bubbles. I might be wrong, but I am too lazy to walk out to the car and check, plus the haynes book doesnt have a picture.

colin_barnes

This piece is in the engine compartment. It is T-shaped and is inverted. One
5/8" heater hose runs from the firewall to the firewall side horizontal T position, one 5/8 heater hose runs from the front side horizontal T position to the front of the engine, one 5/8" hose runs from the top position connection to yet another coolant connection screwed into the back of the passenger side head (I had to remove this from the original L28E when I put the new engine in)- it also has a short 5/8" hose that runs from it into the firewall. This piece is a factory piece and it is plastic.. I did notice today that when I got home from work that all those hoses were hot. I was afraid that this T-valve/coupler was a check valve of some sort. I have not had the opportunity to take it off and look at it yet as it has just started leaking - I was just wondering if you all had run into this type of leak problem before...

jfairladyz

No that is not a valve. It simply distributes coolant to both the engine and the heater valve. And yes, mine has leaked. I just pulled the hoses off, put some sealant on it and replaced the hoses and gave it enough time to cure. It hasn't leaked since.

There should be two hoses going to the firewall: the one you described and another one. Ones a feed and ones a return line from the heater core.

colin_barnes

As always, thanks for the info and advice...

Colin

jmmorriso

Mine had what I thought was a plunger in it, seemed like it was supposed to do something other than look ugly. Dunno, didnt want to investigate too much.

colin_barnes

Hey Guys,

I pulled that T-fitting off this weekend and it is in fact a metal T. But it has plastic inside. It appears to be a relief valve. The top of the T is where the relief valve is. It accepts input (coolant) from the fitting in the rear of the passenger head. The only thing I can figure is that it relieves pressure and coolant back into the system upon high rev instances to keep too much pressure from building in the heater core.. I tried to seal the bottom of the T where the plastic is with some plastic weld, but I have not checked it since to see if it is still leaking.

Colin

Bleach

This topic sounds very familar but I thought I already replied to one just like it.

Guys, there are two different systems. Cars with the Auto Temp control and the Manual Heater controls have different heater hose connections inside the engine compartment so make sure you know which one you have before you go making advice. The T relieve valve I believe is on the manual control systems.

Likewise, the coolant connection on the back of the head is different for auto vs. manual heater systems.

RodMoyes

Mines been leaking since the day I bought it 3 years ago... 1 little drop or 2 every day. I figure at that rate it will take about 26.3 years to empty the system. I would fix it, but it will neither make my car faster, or look better... so it's low on the list

Rod.