Here are all your options:
1. You can rip out your heater control valve, replace it with heater hose, and cap off the line coming from the intake (if you have one).
2. You can replace it with another used valve from a boneyard or ebay, if you can find one and hope it doesn’t leak – About $50-80.
3. An aftermarket company is supposed to be making a new replacement valve. One website listed the price as $139. The original AC Delco was about $85.
4. If you don’t have a coolant line running from your intake, you can replace your old valve with the Chevy one and just run new heater hose. Everything will work perfectly.
5. If you do have a coolant line running from your intake and want to keep it - you could cut the tubing at your old valve, leave the rest of the plumbing, and connect the Chevy valve in line between the heater core and old coolant lines.
6. Or, you could rebuild yours for about $25! (insert Tim Allen grunt).
1. Loosen all heater hose clamps from valve, remove mounting screw from wheel well, 1 nut on evaporator case, vacuum line attached to valve, and remove connector from AC switch (2 blade connector pulls straight back).
2. Slice heater hoses at heater core to valve lengthwise and slide a screwdriver in there to pry the hoses away from the heater control valve. Twist the hoses at the other end of the valve to loosen them and remove valve.
3. Slice the heater hoses on the heater core side and gently remove them. Measure the length and replace. They are 5/8” & 3/4" diameter.
1. Try the disassembly procedure on your old valve first. Remove the screw and 1 piece of linkage from the vacuum actuator. Using a pair of cutting pliers, gently pry up the tabs on the bracket. Separate the bracket from the valve with a screwdriver. (I mixed and matched some of the pics from the new and old valve)
2. Pry the outer seal out with a screwdriver and pull out the plastic valve behind it.
3. With the plastic valve removed, you should be able to see another rubber seal inside the bottom of the housing. Using a screwdriver or a paper clip, make sure you remove all of the old seal. Scrape out the edge where the outer seal goes and clean up your old valve. Blow it out with compressed air or flush it with a garden hose. I also sanded my old valve & primed and painted it.
4. Now do the same disassembly procedure on the new Chevy heater valve and remove these 3 parts. 2 seals and the plastic valve. (You might be able to remove the plastic valve and actuator assembly from the heater control valve housing as one piece - without removing the small screw - but you won’t be able to pry the bracket off with a screwdriver. Unscrewing it lessens the chance of breaking the plastic valve).
1. Place the new outer seal over the plastic valve.
2. Insert the new plastic valve into the vacuum actuator bracket. To attach the linkage, rotate the plastic valve until it lines up with the linkage. They are both shaped so that they only match one way. This ensures the valve goes back into the housing in the correct position. Replace the screw.
3. Slide the new valve assembly into your old housing. You may have to straighten the tabs a little to get the bracket to line up. Once it’s centered and in place, tap the tabs down with a hammer or a socket extension and a hammer.
Put the valve back in, warm it up and check for leaks. Done! You've got a brand new valve for $25.
Original heater control valve part #’s:
1985, 1986, 1987 Corvette heater control valve, hot water valve.
AC Delco - 15-5389
GM – 10120965
Replacement Chevy Valve Part #’s:
This valve fits several mid 80’s GM cars. I bought one from Advance Auto and it matched up perfectly. If you get one of the other brands, just make sure the tab cutouts line up to your old valve before you tear it apart. For a parts lookup you can use:
1982-1983 Chevrolet Malibu V6-229 3.8Lw/Gauges (4 Port valve)
1982-1984 Chevy Full Sized – V8 305 w/Gauges (4 port valve)
ReadyAir – 5935 (Autozone brand)
Four Seasons - 74800
Factory Air – 74800 (Advance Auto brand)
AC Delco - 15-5302
Heater Hose Sizes:
Heater core inlet: 5/8” (upper tube)
Heater core outlet: 3/4" (bottom tube)
(first person to quote this post gets a bitch slap