1994 4.0 A/C Question

bozzzz94 · #1 (**permalink**) 05-13-2008, 11:04 AM

I haven't been on here for awhile. I've been deployed-just got back. Okay-a couple of questions. My compressor is screaming to the point in threw the belt. I'm sure the bearing/clutch is bad. For right now-I disconnected the electric lead-and threw on another belt to help make it through the week. I just bought a new compressor, dryer bottle, and an orifice filter, but haven't done anything yet.

Here is the question. I'm worried about contaminating the evaporator box or the condenser. I know that moister can ruin them. That is why I'm thinking I should have the system vacuumed out first. What do you think?

Should I have the system vacuumed out-then change out my orifice tube and compressor?

or

and here is where the confusion sets in. If I do this won't I have moisture in my system again after I break open the system and replace the components after I have it vacuumed?

I'm confused here. Could I get a pointer from someone that had crossed paths with this situation respond.--Respectfully Boz

copper_90680 · #2 (**permalink**) 05-13-2008, 12:03 PM

I would just ask an A/C shop to discharge the system first. They get your refrigerant for free, so they will be more than happy to do that at no charge.

Then you can open up everything and flush all the lines, the condenser and evaporator. You will be surprised how dirty they can be, at least mine was.

Then just put everything back together with new O-ring, evacuate and charge it up.

If your system is on R-12, now is the time to convert it to R-134a.

It's not really that difficult. I bought an A/C vacuum pump on Ebay for about $100 and it really saved me a lot of money in the long run.

Also, welcome back from your deployment

bozzzz94 · #3 (**permalink**) 05-13-2008, 02:39 PM

Quote:

Originally Posted by copper_90680

I would just ask an A/C shop to discharge the system first. They get your refrigerant for free, so they will be more than happy to do that at no charge.

Then you can open up everything and flush all the lines, the condenser and evaporator. You will be surprised how dirty they can be, at least mine was.

Then just put everything back together with new O-ring, evacuate and charge it up.

If your system is on R-12, now is the time to convert it to R-134a.

It's not really that difficult. I bought an A/C vacuum pump on Ebay for about $100 and it really saved me a lot of money in the long run.

Also, welcome back from your deployment

Thanks for the advice Copper. Well, I kind of did the backwards thing. My system must have stuck and I was worried about an over-charge. I bleed it off at the low pressure side already. When my AC wasn't cold I was going to throw a bottle of R-132A in. Well, it was over-charged by the gauge. I thought there must be a blockage somewhere and since these compressor's have soft metal-meaning that the office tubes usually have shards of metal plugging them up I thought that my system had in other words "a blocked artery".

How can I flush the lines you spoke of? Push compressed air with a nozzle threw the lines like when we hook a garden hose to the inlet outlet of a stuck heater core?

A little confused you can tell. I has another van one time (GMC Safari). They vacuumed it out and then I broke the system open when I got back and installed a new orifice tube. Well, that was before I knew about systems getting moisture in them or the desicant in the dryer bottle getting messed up. They damn thing even works till this day with doing everything wrong. I converted it over to the new from the old R-12 and not even a problem. -Thanks Boz

copper_90680 · #4 (**permalink**) 05-13-2008, 02:56 PM

I used something similar to this

eBay Motors: Robinair 17595 Automotive Flush Gun Kit R12 & R134A (item 120260900383 end time Jun-10-08 08:51:19 PDT)

Also, they have flush solvent there or you can buy them at any autopart store. It's worth every penny, ortherwise the debris you have in there now will really destroy your new compressor.

I usually remove the evaporator and the condenser from the van and flush them outside. It's a lot easier that way. They are pretty easy to remove.

As for the lines, since you are redoing them, might as well take all the lines off and flush them through.

There are two things you don't want to flush, they are the compressor and the dryer. If the compressor goes bad, replace it. If the system is opened up, replace the dryer. You will be glad you did.

Good luck and holler if you need help.

cookkd · #5 (**permalink**) 05-13-2008, 05:28 PM

I went through this exercise about a year ago. I used some a/c flush I bought at AutoZone, and blew it out with my air hose. One of the biggest performance improvements was removing the evaporator and cleaning it, inside and out. The evap is about a foot square (roughly), and mine had a round open area for air to flow through that was about the size of a tennis ball. The rest was clogged up with debris, mostly leaves. Really improved air flow after it was cleaned.

Klaus Dieter Cook
Houston, Texas

99f350sd · #6 (**permalink**) 05-13-2008, 10:27 PM

I have a small vacuum thingy you run with a compressor they are cheap and they work...I have never had an ac problem I just charge em up and never clean or flush and always had good luck go figure. I use the vacuum thing now though. Never touched and orifice tube...

Dick

Bear River · #7 (**permalink**) 05-14-2008, 01:18 AM

However, to use the air powered one, you need a large air compressor with a high CFM rating. If you do not have a large air compressor, get an electric pump, which does pull a deeper vacuum anyway.

99f350sd · #8 (**permalink**) 05-14-2008, 08:27 AM

Quote:

Originally Posted by Bear River

However, to use the air powered one, you need a large air compressor with a high CFM rating. If you do not have a large air compressor, get an electric pump, which does pull a deeper vacuum anyway.

What he said!