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IMJ
06-16-2016, 10:37 PM
The expansion valve on my a/c appears to be leaking some oil at a nut at the bottom of the unit. It isn’t at the hose or evaporator fittings. Is there an o-ring or a gasket that is replaceable? Also, was any low pressure cut out switch used on Studebaker a/c? Even though all refrigerant must've escaped, the compressor will run as soon as the control is turned on.


regards,
Jay

karterfred88
06-16-2016, 11:47 PM
Jay, I believe you have an Avanti R! with A/C. That's the best I could glean from prior posts. Not sure about the expansion valve but no there is no low pressure switch, the on knob engages the compressor clutch-very basic. Take a picture of the expansion valve-maybe someone will know for sure. Since so many parts have been used on our cars, especially A/C systems to repair them seeing the one you have will get a more positive answer, especially if it was upgraded to R134 at some time.

doofus
06-17-2016, 06:45 AM
Just checked 2 A/C equipped Studes, no nut on expansion valve. opposite small diaphram with capillary tube is fitting to attach to evap. core. it's possible to have a crack here in flare on tube IIRC. bummer having to replace evap. core. Luck Doofus

jackb
06-17-2016, 07:46 AM
If you need a NORS replacement valve...I've got one. PM me.

doofus
06-17-2016, 02:41 PM
Jay checked other units in shop.expansion valve is threaded on end away from diaphram end,tube from evap. core has matching flare and large nut and could be cracked at base of flare. you could try soldering if cracked. Luck Doofus

IMJ
06-18-2016, 07:29 AM
Take a picture of the expansion valve-maybe someone will know for sure. Since so many parts have been used on our cars, especially A/C systems to repair them seeing the one you have will get a more positive answer, especially if it was upgraded to R134 at some time.

This is on an Avanti R1. The oil seepage was at the short stem at the bottom of the nut of the expansion valve. The system was converted to R134a at some point and has a "G.P.D." compressor in place of the original. The dryer/accumulator appears to be in the original location next to the radiator/ condenser. If an original style is available, should it be replaced too? Thanks all for the info! I might take you up on your offer Jack. Does "NORS" stand for New Old Replacement Stock or New Old Rebuilt Stock?

55441

regards,
Jay

karterfred88
06-18-2016, 08:53 AM
Looks alot like a Ford unit with a sight glass. http://www.classicautoair.com/FORD_OEM_Parts_Valves.html They can also rebuild yours-but why bother if one of those fit and work, not a judging item as far as I know.

StudeRich
06-19-2016, 01:56 AM
When changing from R-12 to R-134 the Dryer SHOULD have been replaced, if not YES replace it.

karterfred88
06-19-2016, 11:53 AM
Since your system is "open" already-no Freon, it is very important to replace the dryer whether it truly matches your old one or not, one can be adapted into your position and bracket. You can not realistically draw out all the moisture from it and make it useful. Putting a valve in and not thoroughly cleaning evacuating and replacing any questionable hose, seal, and all the old oil is just wasting your time.

IMJ
06-20-2016, 08:02 AM
Looks alot like a Ford unit with a sight glass. http://www.classicautoair.com/FORD_OEM_Parts_Valves.html They can also rebuild yours-but why bother if one of those fit and work, not a judging item as far as I know.

Once again thank you for the info. As to replacement of the expansion valve, as long as the fittings match the one that is currently on the car, there is no adjustment? And likewise with the drier? My system registers 5 psi on my gauges so I guess it was not completely empty or open. To evacuate the system after parts are replaced, do I just hook up a vacuum pump? Does that also remove all the oil from the system? If it does, do I need to add oil separately to the system or use refrigerant that addtionally contains oil?
regards,
Jay

karterfred88
06-20-2016, 09:38 AM
Once again thank you for the info. As to replacement of the expansion valve, as long as the fittings match the one that is currently on the car, there is no adjustment? And likewise with the drier? My system registers 5 psi on my gauges so I guess it was not completely empty or open. To evacuate the system after parts are replaced, do I just hook up a vacuum pump? Does that also remove all the oil from the system? If it does, do I need to add oil separately to the system or use refrigerant that addtionally contains oil?
regards,
Jay
Depends on where you live, to vacuum the system, you need to empty what's in there, most service facilities have a machine that "saves" the extracted Freon, vacuums the system, and then recharges it. "Technically" it is "illegal" in most states to release the Freon left in the system "knowingly" into the atmosphere. Since you have an "almost empty" system-5 psi is probably just moving around air and oil still in the system without any Freon at all, it would be possible to just vacuum the system, but without disassembly and cleaning the system, you have no way of measuring the oil already in the system, to know whether you need to add Freon with or without it. If you clean and flush everything, then you can add the prescribed amount of oil into the system at the compressor, charge with clean new Freon only. It's a pain to follow "rules" and you can probably "get by" adding plain Freon with only a small oil addition on the refill, depends on how much oil you spray when you pull those hoses off the valve, and how much left inside the dryer canister-but if you seize your compressor- after- it can get expensive.

WCP
06-20-2016, 12:12 PM
Try tightening the slotted sight-glass window retainer with an appropriate tool. If it turns to tighten, then that is probably the source of your leak. Found that out on a Hawk system. Once tightened, the system proved to be very tight for many years 'till I sold the car.

IMJ
06-25-2016, 06:49 PM
My Avanti shop manual doesn’t have an air-conditioning section in it. My 59-64 Lark shop manual has a very limited section. I could speculate why, but it would be just that, speculation. My Avanti appears to have the original “dehydrator/receiver tank” (drier/accumulator) next to the radiator support. The receiver has a 4-sided bolt at the bottom which looks like a drain plug. It appears that the only way to remove the receiver is by removing the radiator in order to get to the mounting bolts. I don’t know how the receiver/drier is constructed but is it serviceable or cleanable by draining whatever from that drain type plug? Thanks again!


regards,
Jay

IMJ
06-30-2016, 07:45 PM
Since I couldn’t find a section on air-conditioning in my Avanti shop manual can someone give me some direction on removing the condensor? I prefer not to take apart more than is needed and since I can’t see where the upper support brackets are attached it looks like the radiator must get pulled first. If not, is there room to pull the condensor from the lower air intake? Thanks!

regards


Jay