Working on my 67 AC and was forced to replace the expansion valve. When I took the old valve off I noticed it was stamped (Frigidaire Symbol) over Frigidaire on one side, a symbol that looks like a bomb standing upright with a "T" on the other side, and on one of the outlets an arrow for flow direction on one side, an "H" on the other, and A2 7 at the base. I assume the A2 7 is January 2, 1967, which is consistent with the my car build date. Having seen all of that, I would love to rebuild it and put the original valve back on the car. Can this done?? Let me know. Thanks.
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go for it---i'm pretty sure kits are available *NM*
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Re: Rebuild Original AC Expansion Valve (67)??
Kirk-----
Dr. Rebuild has the repair kit you need. Others may, too.In Appreciation of John HinckleyComment
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Re: Rebuild Original AC Expansion Valve (67)??
Kirk - I'm a bit confused as to what part everyone is referring to rebuilding here but if folks are referring to a kit to rebuilt the 67 Corvette A/C expansion valve it's good news and something somewhat new and I'd be curious about other's experiences with rebuilding these expansion valves because they appear to be sealed (non-serviceable) units. If we're talking about the 67 POA valve, it's also a sealed unit, but I have heard that some of the A/C rebuilding shops can in fact rebuild these but here again I'm not familiar with any kits that are available to individuals to perform the rebuilding operation.
Hopefully, someone has used these kits and can provide some additional information on their experience. Good luck.
PeteComment
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Re: Rebuild Original AC Expansion Valve (67)??
Hi Kirk:
The 1967 expansion valve can not be rebuilt by conventional means, but sometimes it can be cleaned and restored to functionality. Classic Auto Air in Florida (813-251-2356) can clean and test the valve for you. They recently tested mine and I was pleased to learn that it was okay.
The reason that these valves can not be rebuilt by conventional means is that they contain a sealed charge of Freon in the sensing bulb, whose temperature-sensitive pressure is used to control the valve. If this sealed charge is lost, most rebuilders (including Classic Auto Air) will deem the valve unsalvageable.
That being said, I recall reading on the internet a description of how an enterprising fellow managed to rebuild and re-charge his expansion valve, but I do not recall the link. So, keep your old valve even if it is defective, and maybe some day you can find a way to get it rebuilt.
The other valve in your system, the POA valve, also can not be rebuilt by conventional means. However, Classic Auto Air has a method for cutting these open and rebuilding them, then welding them back together.
If you have your A/C system apart and are unsure of what the problem was, I suggest that you have the POA valve checked out as well.Comment
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Re: Rebuild Original AC Expansion Valve (67)??
Hi Joe:
Are you sure that you are referring to the 1967 expansion valve? The pre-67 STV valve was rebuildable, but the STV valve was replaced by the POA valve in 1967. I believe the 67 expansion valve is a sealed unit that can not be rebuilt by conventional means. It was my impression that pre-67 Corvettes used a similar, non-rebuildable expansion valve, but I'm not certain of that.Comment
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Re: Rebuild Original AC Expansion Valve (67)??
Joe----
Yes, I think I was thinking about the POA valve. I don't think that the expansion valve is rebuildable and I don't know of a source for parts for it, anyway.In Appreciation of John HinckleyComment
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Re: Rebuild Original AC Expansion Valve (67)??
Joe,
I was going to "rebuild" the POA valve with "67 P.O.A. Valve Update Kit" sold by Corvette Central which "Replaces the original POA valve and converts it to a more reliable cycling clutch system improves performance wuth new automotive refrigerants". So, if the valve is sealed, what heck is this kit??? Ahh, always something.
My problem with the air is the high end reading is sky-rocketting and won't settle down. It reads about 300 PSI? at the start but rises to 400-450 once the engine is running. Problem being that at that pressure I am likely to blow a hose going down the road. Crap, nothing is ever easy with these cars!!!Comment
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Re: Rebuild Original AC Expansion Valve (67)??
Kirk,
"Crap, nothing is ever easy with these cars!!!"
Things are a lot easier with these cars than late model cars. With "compact packaging" (10 pounds of stuff crammed into a 5 pound sack) and all the electronics, nothing is easy on the new cars.
In reference to your problem, yes, 400-450 is excessive. That suggests something is restricting flow. Check the POA valve carefully for debris. If you find significant debris you should look for a source of that debris. Likely sources are the compressor and the dryer/accumulator if it is in the high pressure side. Debris can suggest progressive failure of the compressor.
In any case, you should replace the dryer and probably flush the system to get debris out or it will just plug up again.
Good luck,
VerleComment
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Re: Rebuild Original AC Expansion Valve (67)??
Flushing your system as a service procedure should be done in the event of a Catastrophic Component failure. Usually the Compressor crashes. The POA is a critical component and it's proper operation is paramount to proper operation of the system. And, contrary to popular belief that it is a Non-adjustable device, it is adjustable. Different settings are required for R-12 vs R-134. The following site is a wealth of information if you use the search function well.http://www.autoacforum.com/messagevi...AR_MSGDBTABLE= Search all posts by author "MITCH". Mitch has sadly left this world but his knowledge is second to none. Also, I recently purchased a "Correct" Expansion valve from a supply house in Texas. If I find the link I'll forward it. Do a Google search and you'll find them. To be correct the sensor portion of the Expansion Valve must have the "J" shape. Too many vendors try to sell the straight sensor as correct. NOT! Al W.Comment
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Re: Rebuild Original AC Expansion Valve (67)??
Here you go. Old Air Products, Texas. http://www.oldairproducts.com/shop/p...7970a416e46711 Al W.
PS. Stay with R-12. It is a more efficient agent than R-134. These older systems require all the help they can get.Comment
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Re: Rebuild Original AC Expansion Valve (67)??
Hi Kirk:
I think you should go slow here. These A/C systems are a bit complicated, and if you want to keep things original and avoid unnecessary repairs, you need to proceed carefully.
First, the "POA update kit" looks different and works differently from the original. A lot of people use this kit when their POA fails, but if originality is important to you this may not be a good choice.
In the 67 system, the comppressor runs continuously and the POA acts as a pressure regulator to manage the low side pressure in the evaporator. The POA's job is to keep the evaporator pressure as low as possible without letting it go so low that condensation freezes on the evaporator. With the "POA update kit" the compressor is turned on and off in an effort to manage the low side pressure. This works but I'm not sure it represents a functional improvement.
Next, there are many causes for excessive high side pressure, one of which, I believe, is air in the system. Other possible causes are restrictions on the high side circuit. I have some documentation on diagnostic procedures that I can try to dig out if you want. Also, I think the 67 service manual contains some information.
If your system is still intact, you may want to take the car to an experienced A/C person for diagnosis. Alternatively, you can read up on how to diagnose the system and try to figure out the problem yourself.
I am in the middle of rebuilding my A/C system right now, and one of my goals is to eventually understand the system well enough to service it myself. I have done some research and have gathered some useful documentation that I can share with you, but I don't yet have it all figured out.Comment
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Re: Rebuild Original AC Expansion Valve (67)??
From the picture, the J-hook on the line is fine, but the exp valve body does not resemble the original. Probably not made by Frigidaire, but I'm sure it will work as a replacement.
BrandonComment
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