AC advice

[SplotchyAphid05]

I have a 1990 2.9 that at one point had AC but the previous owner pulled the compressor from what I can tell since I have a compressor bracket and condenser and accumulator along with all the lines so I am looking at trying to get the AC operational again and am wondering if I need to replace every component in the system or just getting a compressor or even trying to run a window unit off an inverter or if its even worth the trouble of messing with

 

[JoshT]

Personally I think window unit looks sloppy and shouldn't be put on a vehicle except in a few special cases. Namely a van or box truck that is converted into a mobile office/work space or camper. Then it should be plugged into an normal AC outlet, or should be run off a battery bank and inverter, not off of engine power and inverter. That's my 2 cent on the window unit.

As for repairing the AC, you know you need a compressor. You also need a reciever/dryer, they contain a dessicant material and will go bad if exposed to atmosphere for long. With the compressor gone the system is open and yours has been exposed way too long. You could install those and try your luck, but I wouldn't. Since you don't know the condition of the system, I'd replace everything. Here's why...

You don't know what happened to cause PO to remove the compressor. If the compressor died violently it's likely contaminated the rest of the system (look "A/C Black Death") and can be almost impossible to clean out. If this is in the system, it is likely to either block the tiny passages in the condenser (behind grill) and evaporator (on firewall), or block up the oriface tube screen. It could also turn loose and damage the new compressor and other parts.

If you have any leaks in the system, you would be wasting freon which isn't cheap. With an assembled system you can test of leaks with vacuum, but the only way to really find those leaks is with a charged system and leak detect dye. Again wasting freon and money on paying a shop to do all of this.

You may be converting from R12 (no longer available) to R134 (it's replacement). When doing this it is best to replace all of the o-rings in the system to ones that are compatible with R134, otherwise the new stuff could cause the old seals to break down. At it's age, it would be a good idea to put all new seals in anyway.

With what you are already spending, the additional parts don't cost that much more. By the time you pay a shop to do all of the potential troubleshooting, you could have paid for all new components. Install them yourself, easily doable since the system is already discharged, and add required oil in correct amount during assembly (there are instructions around). Then you only need to pay the shop for freon and charging the system. Just if you do this, leave the compressor electrically disconnected until it is serviced. It shouldn't run until serviced anyway, but better safe than sorry.

 

[JerryC]

A few years ago I went through this on my 88 BII except it had bad compressor still on it. I figured my luck would be like JoshT says and I'd just eat up a new compressor so I replaced everything.

I think it worked out to be a $1100 in parts/tools. and 10 hours of time including sourcing the parts (except the evaporator). I had not done any AC work prior to that. The hardest part was the evaporator that took a solid hour of cussing to get it replaced. Would probably have been at least 2x the cost for a shop to do it.

Most of the parts I could get from Autozone back then, compressor, lines, condenser, accumulator/drier and orifice tube. Every evaporator I got from Autozone was damaged in shipping. Got a vacuum pump and gauges from Harbor Freight.

Good luck on this, I really enjoyed the learning process doing mine.

 

[Poppa_R]

Having worked on many a/c systems, I would recommend replacing the receiver/dryer and expansion valve plus your compressor that is missing. I have used a chemical flush on everyting else, hoses, condensor and evaporator. You get the chemical and tool from your local auto parts store.

 

[JoshT]

I have used a chemical flush on everyting else, hoses, condensor and evaporator. You get the chemical and tool from your local auto parts store.

From what I've read, many auto HVAC professionals recommend against trying to clean them. They say that because these units are parallel flow, and because of the small tubes, a solvent flush won't properly clean them. That even after a flush you are likely to still have stuff in there that will turn loose and cause problems.

I'm no expert, I just defer to their judgement for some things.

 

[JerryC]

From what I've read, many auto HVAC professionals recommend against trying to clean them. They say that because these units are parallel flow, and because of the small tubes, a solvent flush won't properly clean them. That even after a flush you are likely to still have stuff in there that will turn loose and cause problems.

I'm no expert, I just defer to their judgement for some things.

When I was doing research I ran across the same advice.