GM Parts & Services
What does a heater valve do?
The heater control valve regulates, by opening or closing, the amount of hot water that enters the heater coil.
Why restore or replace your heater valve?
A good indication that your heater control valve is failing is if your air conditioning is functioning correctly and your system gauge readings are correct, but you’re getting heat or warm air out of the vents. This could be as a result of a failed heater control valve that will not shut off the flow of water to your heater coil. The heater control valve can also fail by leaking, or even by not opening and allowing water to flow into the heater coil in heat-mode.
Buy a new Heater Control Valve or let us restore yours!
Classic Auto Air carries new heater control valves, we have thousands of NOS & NORS. We also offer restoration services for most lever operated heater control valves. Please call or email for more information.
Restoration services available for most lever operated heater control valves. Please call or email!
What is an expansion valve?
The expansion valve is mounted at the evaporator inlet and regulates the refrigerant going into the evaporator.
Buy a new expansion valve!
We offer new, replacement GM expansion valves, including for 1962-73 GM vehicles. Please call or email!
1962-73 GM Expansion Valve (CAA part #15-205)
Many other replacement new, reconditioned, NOS & NORS expansion valves available. Please call or email!
Why replace or restore my expansion valve?
Most a/c technicians will automatically change out the expansion valve as it’s commonly a source of air conditioning failure. A good indication that your expansion valve has failed or is failing is a negative or high system gauge reading. This is either as a result of contaminants clogging the valve up or valve failure.
Because many valves are no longer made, Classic Auto Air offers testing and reconditioning services for your original. There is also a good chance that a NOS or NORS might be available. Please call or email!
Expansion valve reconditioning consists of:
- Flush clean internally
- Clean externally
- Zinc plate.
(Hot Gas, Suction-Throttle, POA & VIR)
What is a suction valve?
The suction valve is found on most 60’s and 70’s GM vehicles. There are several different types, generally varying by model year as follows:
|1955-61||Hot Gas Valve|
|1962-66||Suction Throttling Valve|
The first three are all different kinds of suction valves. They are mounted to the evaporator’s suction (top) outlet and regulate system pressures so as to prevent the evaporator from freezing up.
The Valve-In-Receiver is a POA valve, drier, and expansion valve all in one. It too is mounted on the Evaporator.
Why restore my suction valve?
A good indication that your suction valve has failed or is failing is a high low-side system gauge reading. This is either as a result of contaminants locking the valve or clogging the valve up or valve failure. If you’re converting to 134a, your valve will need to be properly calibrated as by-pass pressures differ from that of R12. More on Converting to 134a!
It is hard to find new replacement, NOS and NORS models of the various GM suction valves so Classic Auto Air offers restoration services for each.
Hot Gas Valve Restoration
We can restore your GM hot gas valve.
Hot Gas By-Pass Valve rebuild consists of:
- Disassemble, inspect, clean and replace damaged or missing parts.
- Zinc plate all external pieces
- Install new seats & O-rings
- Assemble & test
Call or email!
Suction Throttling Valve Restoration (STV)
We can restore your GM suction throttling valve.
Suction Throttling Valve (STV) rebuild consists of:
- Disassemble, inspect, clean and replace damaged or missing parts
- Install new internal diaphragm & O-rings
- Assemble & test
We can restore your GM POA valve. We can either recondition it or rebuild it.
POA Valve reconditioning consists of:
- Test & flush clean internally
- Zinc plate
POA Valve rebuild consists of:
- Cut open, disassemble
- Inspect, clean and replace damaged parts
- Calibrate for R12 or 134a
- Zinc plate
Rebuilding services are only available only available on an original Frigidaire valve. Delco valves are not rebuildable. For more information on the difference, please click here.
What does a POA valve do?
All air conditioning systems have something built into the system to prevent the evaporator from getting so cold that it freezes up. In some systems, this mechanism is a thermostat, but in most mid 60's to mid 70's GM vehicles, it's a POA (Pilot Operated Absolute) Valve.
A thermostat prevents the Evaporator from freezing by cycling the compressor on and off based on evaporator temperature. A POA Valve prevents the evaporator from freezing by by-passing excessive system pressure. Note that in a POA Valve type system, the compressor runs constantly whenever the air conditioning system is operating.
Why have my POA valve calibrated, reconditioned or rebuilt?
If you are converting to 134a, your car's POA valve will need to be calibrated to by-pass at different pressures. We offer 134a calibration with any reconditioning or rebuilding service.
A good indication that your POA Valve may be failing is a high low-side system gauge reading, a normal high-side system gauge reading and no cooling.
Here are some before and after pictures of POA Valve rebuilds:
|Buick Skylark, GS & Special late 65-73||15-51 Type-1|
|Buick Electra late 65-72||15-52|
|Buick LeSabre late 65-72||15-52|
|Buick Riviera 66-70||15-51|
|Buick Riviera 71-72||15-52|
|Buick Wildcat late 65-70||15-52|
|Cadillac late 65-early 73||15-52|
|Chevy Corvette 67-72||15-51 Type-1|
|Chevy Camaro 67||15-51 Type-1|
|Chevy Camaro 68-69||15-51 Type-2|
|Chevy Camaro 70||15-51 Type-1|
|Chevy Camaro 71-73||15-52|
|Chevy Chevelle 66-68||15-51 Type-1|
|Chevy Chevelle 69-72||15-51 Type-2|
|Chevy Chevelle 73||15-51 Type-1|
|Chevy El Camino 66-68||15-51 Type-1|
|Chevy El Camino 69-72||15-51 Type-2|
|Chevy El Camino 73||15-51 Type-1|
|Chevy Impala & Caprice 66||15-51|
|Chevy Impala & Caprice 67-73||15-52|
|Chevy Monte Carlo 70-73||15-51 Type-2|
|Chevy Monte Carlo 73||15-51 Type-1|
|Chevy II/Nova 68||15-51 Type-1|
|Chevy II/Nova 69-early 74||15-51 Type-2|
|Chevy & GMC Truck 67-72||15-51 Type-1|
|Chevy Vega 71-72||15-52|
|Olds Cutlass, 442 & F85 late 65-mid 73||15-51 Type-1|
|Olds Delta 88/98 late 65-73||15-52|
|Olds Toronado 66-70||15-51 Type-1|
|Olds Toronado 71-72||15-52|
|Pontiac Bonneville 65-70||15-51 Type-1|
|Pontiac Bonneville 71-mid 73||15-52|
|Pontiac Catalina 65-70||15-51 Type-1|
|Pontiac Catalina 71-mid 73||15-52|
|Pontiac Grand Prix late 65-70||15-52|
|Pontiac Grand Prix 71-early 73||15-51 Type-1|
|Pontiac GTO, LeMans & Tempest 66-72||15-51 Type-1|
|Pontiac Firebird 67-69||15-51 Type-1|
|Pontiac Firebird 70-73||15-52|
Valves-In-Receiver (VIR) Restoration
We can restore your GM Valves-in-Receiver (VIR). A VIR is a combination POA valve, drier and expansion valve all-in-one. Note that because it contains a drier, you should change the desiccant in it every time you open the system.
VIR (Valves-In-Receiver) Restoration consists of:
- Inspect, clean and replace damaged or missing parts
- Install new seals & O-rings
- Paint, assemble