Venom_1138

When I bought my car, the previous owner told me that the A/C was disconnected because either the pump was shot or it just needed to be recharged. Judging by, well, a LOT of what I've seen on the car, I think it's pretty safe to assume he was not mechanically inclined, so I'd say it's a 50/50 chance that either one is possible.

Is there a way I can test the A/C pump without spending too much money to do so? I don't want to waste money trying to fix a broken part if it's just something that needs to be replaced, but I also don't want to replace something unnecessarily, either.

sofakingdom

iTrader: (1)

If it's been exposed to outside air, it's probably beyond recall. Contamination is as bad for them as wear or whatever.

There's not really a good way to "test" them.

They usually fail either by the bearing surfaces wearing out, which sheds debris all into the system; by leeeeeking, which can be VERY hard to detect without completely assembling the system and attempting to evacuate and fill it; or by the little reed valves disintegrating. Although, you can maybe get a hint of the situation by careful visual inspection: debris from the compressor will show up in the orifice tube screen and clog it; and the most common leak is from the seal behind the clutch, which leaves a residue of oil on the underside of the hood. Leaks elsewhere will show up as oil at that place, so a joint or the end of a hose for example will be all nasty with old oil.

Best most likely to succeed practice is to just replace the compressor, accumulator/dryer, orifice tube, the rubber sections of the lines, and every O-ring. I've detailed how to attack it many times: Advanced Search this site for "orifice tube" and my userID. You should get a pretty repetitive list of what to do.

sofakingdom

iTrader: (1)

I would add, given the absolute and complete interchangeability among them (that is, they're nothing but a pump; just like the water coming out of your faucet doesn't depend in any way on the brand of pump that pumped it, your AC doesn't depend on what brand the compressor is) and how CRAPPY the old GM units were, that if you decide to buy one, you'd be better off buying a conversion to something modern. The price isn't all that different, but the performance, reliability, and efficiency (engine power consumption) ARE.

Venom_1138

That answers my question perfectly, from the sound of what you said, I'll probably have more success using the existing A/C compressor as a paper weight. Thanks for the reply, much appreciated!

Venom_1138

Just going to continue this thread instead of creating another:

With summer approaching, I'm hoping to try and see if I can tackle the AC finally so I'm not roasting in the summer heat, especially if I go on a long highway drive. Windows down and T-tops off can keep things cooler, but the wind is crazy loud at anything above 45, and I'm hoping to take a little road trip mid-summer.

So in keeping with the above advice, I'm going to pretty much need to replace the entire AC system, which seems like it should be pretty straightforward in and of itself. But before I dive into that, there are a couple of other items related to the heating/cooling system that I probably should make mention of so I can do it once and do it right.

First off, the PO pulled the heater core entirely, and just married up the two tubes from/to the cooling system with a connector and a couple of clamps. Will I need to have that replaced before I get the AC replaced as well? Not just in terms of things working properly, but in terms of not having to disconnect my AC again because it's in the way whenever I decide to replace the heater.

I was monkeying around inside the car the other day, and just for kicks decided to test the air fans. Good news is they work, less good news is the air will only blow from the defrost vents. Not that leaving it set to the defrost vents won't keep the car cool, but if there's a potential bigger problem underlying that, I'd rather tackle it now and head it off. Plus some days it's just too flipping hot and having the AC blowing right on you is a lot more refreshing than just having the defrost vents trying to cool the overall ambient temperature.

Drew

iTrader: (58)

Quick and sleazy answer... The compressor - I'd assume it's junk, but I wouldn't be adverse to trying it, assuming you mind the risk that it might leak or be junk and you'll have to do the job again. In my personal experience and a sample set of two ancient R4 compressors of indeterminate history of abuse, I had one that I charged up and held pressure for two years, blew cold air, and only made slightly unhappy noises once in awhile. Specifically it seemed like it loaded the entire accessory drive a little more than it should, but then we're dealing with 80's cars here, so who knows. This being the third season, it's leaked down enough I really need to recharge, or try replacing the compressor. The other blew cold, but leaked significantly, needed a recharge after a couple weeks. This compressor was bad enough (leaking) I could tell by looking under the hood, black blood of the earth debris field inline radially from the compressor pulley. I'd expect a replacement compressor would correct this.

Read up on A/C rebuilds, you'll want an orifice tube, dryer, O-rings, oil, and refrigerant. Consider replacing the service port valve cores, inspect the hoses or replace, clean EVERYTHING. Vacuum down, recharge, cross fingers. A person could go a step further and replace everything, but on two cars, one that has had R12, R134A, and air duster, and the other that was hit by a train, the condensers appear to have been fine, hoses OK, and so on. But then I haven't addressed the compressors that I assume are the cause of my gross and slow leaks, so FWIW.

The heatercore is no biggie. Again, use Google add site:thirdgen.org and read. Some of us have uploaded photos showing the difficult to reach screws, that may or may not still be there (long story).

The reason your fans only blow out the defrost is your vacuum operated valve that flips the various doors in the vents opened/closed is leaking. It's held together by a plastic clip, that clip breaks under the pressure with age. There's several threads with photos on replacing the busted clip with a bolt and nut. Google. The other potential cause is the vacuum line under the hood from the engine to the heater control may be disconnected or leaking. Look on the firewall below the heater core tubes, down by the frame rail on the passenger's side you'll see a rubber bulkhead plug with a bundle of wires and a plastic vacuum line. That line is the one that goes to the engine. Make sure it's properly connected to engine vacuum, probably by way of a valve/tee that runs to the engine, vacuum reservoir (orb of unknowing), cruise control, etc. Again Google is the magic info finder.

Good luck, and may the pleasure of climate control forever aid your road trip.

Venom_1138

Resurrecting the thread again as I'm continuing to mess with my AC system.

I decided to just yank out my AC system last weekend. It's totally dead, so it was just dead weight and unnecessary clutter in my engine bay. I haven't had AC in the two years I've had the car, and thanks to the glory of T-tops and power windows, I've gotten by just fine.

However, the removal just left me with one question, and that is what to do with the remaining opening from behind the aluminum canister as seen here:

​​​​


Now even though I don't have AC, I do still want to be able to pull fresh air into the cabin, like if I'm forced to roll up the windows due to a surprise rain shower, etc. So I don't want to pull or block anything off unnecessarily, I just want to make sure I'm not sucking in any bad air or leaving an opening for yellowjackets or something to try and create a nest in. Plus, I may decide to reinstall a new AC system later on after I do some other work on the car, so I don't mind leaving any components I may need later on since they'll be out of the way.

Also, I was able to pull the condenser coils, but I realized that they also serve the purpose of keeping my radiator in place. There are two rubber feet on top of the condenser that the radiator is braced against, and without the condenser the radiator would be able to move back and forth. Is there some kind of bracket made that would fit in place of the condenser to hold the radiator still once its pulled?

​​​​​