Hello all,

So, I got bored again... I know, things get strange when I get bored.

I got the wild idea that I should take apart my non-functional A/C system to try to find the leak. Here comes the story:

Before disassembling anything, I got out my A/C pressure testing gauge. The (I think) low side near the condenser was reading pressure into the red. I found this odd since I wasted a can of R134a just to listen to it hiss out of what sounded like my condenser. I thought, OK, let's see what kind of reading I get if I run the A/C. After manually bypassing the pressure switch, the clutch engaged and I got a nominal pressure reading. I shut her down and opened the Schroeder valve on the high side (driver's side near battery). I got a good strong hiss but no blast. The low side was very weak when opening the Schroeder valve.

I noticed my A/C compressor was quite hot to the touch and the line to the passenger side was hot while the other was warm. Since I think my evaporator is my problem, I attempted to remove it. I was unable to loosen any of the connectors on the passenger side, so I thought I would disconnect the lines from the compressor and remove the condenser that way, with the lines attached. Well, no dice. I still can't get the condenser side connectors loose. The ones on the compressor were a real B. I had no idea you could get 800 ft/lbs of torque on an aluminum fitting!

I'm not sure what else I can do but I do remember a hissing coming from the condenser on the passenger side. The PO smashed up the box that houses the condenser, probably looking for the same leak and not knowing how to unscrew the bolts that hold it on.

Another thing, I hope I don't need the insulation that was facing the exhaust manifold, because it had to go. It was all torn up and in my way, so I removed it. Any suitable replacement?

 

The pressure should be checked while running. The compressor should be hot as should the small line. the large or "low pressure" side at the evaporator should be 40 psi or so. But has it already been converted to 134a? My advice woulld be shoot some die in there and put a can in, then check it at night with a black light, fix where the glow is. when you get it back together and then the system should be evacuated, then charge it up!

 

I checked the pressure while it was running, too. It barely registered anything. The smaller of the two lines was the hot one. It is R134a converted. How do I evacuate the system?

 

You need an evacuator. I bought my gauge set hoses and evacuator along with an o-ring set and a can tap for $110 though ATD, it all come in a case kinda handy. For what the evacuator is i can't imagine them being expensive. What it does is it uses compressed air to pull a vacuum on the system while drawing out the moisture and oil. You leave the vacuum on and suck in the first can of oil and and then charge it with 134a. See charging from 29inhg instead of 0psi allows more refrigerant in the system and it will cool better because its not contaminated with air.
Heres the set i got
ATD-90 - AC Bag Kit - ATD Tools, Inc.
And if you have alot of friends with crappy cars it canpay for itself very quickly, just charge them 10bucks over refrigerant costs
The only extra thing you need is one of those can vales you can get at the auto parts store so you can charge though the gauges, if you want i can take a picture of the crittter I'm talking about

 

was it micky mouse converted to 134-A, or was it professionally done?
if it was micky moused with the $29.99 auto store kit, i would look closely at all the components, cause those kits usually lead to "black death", which requires a truck load of money to fix.

 

Yeah, if you could take a picture, that would be great. I have a can tap with a gauge and a connector for the low port. It came with the R134a can I bought.

I'm not sure who or when the system was converted. It looks professionally done to me.

 

Some info that may help...An AC system is separated into a high pressure side and a low pressure side. The compressor and the orifice tube are the separation points. The compressor pumps the gas to the condenser where it turns into a high pressure liquid. The gas goes through the orifice tube and the pressure drops quickly which causes the freon to turn cold. It becomes a low pressure gas in the evaporator which the compressor pumps and starts the cycle over again.. You have to make sure the system is vacuumed down good to remove water from the system. What happens is that water vapor will freeze when it drops suddenly in pressure just like the freon does but what happens is the water will turn to ice and cause a blockage at the orifice tube. The reason you vacuum a system is to get the liquid water to turn to a vapor so the pump can get it out. You know that when you put a pressure cap on a coolant system it raises the boiling point of water? That works backwards. You lower the boiling point of water when it is under a vacuum. There is a huge difference between 26 inches of vacuum and 29.5 inches when it comes to that. Get your truck vacuumed down good. To do it right it needs to be vacuumed for a good amount if time. A few hours minimum on a hot day. As far as converting them. I have done several and the parts I change are the accumulator. Years ago they recommended allot more parts but I have had no problem with just the accumulator and a good vacuum. My 83 was converted and I ran 4 lbs of 134 in it and it did very well. Unless you know how to use manifold gauges just use your low side hose thing for your small cans. If you have a set of manifolds then don't hook your high side hose up while you are charging so you don't accidently send high side pressure in the can. That can be bad. Like hospital bad.

 

Heres the critter I have,
Air Operated Vacuum Pump
They do work best with the manifold gauges because they can pull the moisture out of the whole system with out haveing to try to pull through the compressor or orfice tube.

 

Eaton9999 Check your email I sent you a couple of pdfs that should help with the air conditioning it sounds like you have a leak in the evaporator or maybe the drier.

 

I got one of those vacuum deals at Harbor Freight for $13.... doesn't come with any hoses though.


Air conditioning? On an 86? When did this happen?!

 

IN 84!

 

There is an entire A/C system in my living room, minus the compressor. Good thing I'm single right now or my girlfriend you probably kill me.

I think my condensor/dryer has a leak because I heard hissing coming from it when I tried refilling the system. I'll take pictures because I know y'all love pictures.

 

The condenser and dryer are in my bathtub awaiting a pressure test. I'll blow into one end and cover the other and see if there are any bubbles coming up.

When I replace all the O-rings in the system, can I use the pack of green ones at AutoZone? Are all the correct sizes in there? How do I get the swivel fitting off to replace the O-rings in there? Special tool?

Some of my fittings have black O-rings on them so I am going to say that Mickey Mouse did convert it to R134a. There is a brown liquid in some of the fittings, I assume that is bad.

 

Well, not all of it is brown, some is bright green.

 

The green O rings are for the r134a so new O rings all around just on principal while you have the system open and a new drier (if you are lucky the leak will be on the drier and not the evaporator) only replace the evaporator if that is where the leak is.