It is really warm here in northern Europe so i would not mind having the AC working on my 1999 Blazer ZR2.

I have turned the heather ***** to max AC and it does not blow cold at all.

I guess that the AC system is drained for R124a coolant so i will need to refill the system

From what i can tell it takes about 1 LB, 12 OZ or in european measureement 0,79 kg

If there is a leak i guess the most comon places the system canleak is the compressor fitting or the condenser?

Anything i should test first?

 

I'm about to dig into my AC system today. I consulted with a local shop to do the repair work for me but when I realized I could probably save over $500 I decided to do it myself.

The shop guy confirmed my suspicion that the leak I had was likely at the body of the compressor. We found an oily residue under the compressor, on top of the compressor mounting bracket. You might check there.

If that is the case, you will need at least a new compressor. If it only recently failed with no significant oil loss, the rest of the system could be clean. However, the instructions that came with my new compressor said that any warranty is void if I did not also do a system flush and replace the condenser as without oil, the compressor will wear and small bits of it will move through the rest of the system.

A quick solution is to get one of those R134A in a can recharge systems and try recharging your system. If you see any oil where I did, be sure to get one that also has oil in it. However, this is just a stop-gap solution. If you use anything with a sealant in it, that could mean replacing many more parts since the sealant could clog the rest of the system.

 

 

I'd advice:

• fill in nitrogen, check system for possible leaks (Your refrigerant has leaked so You probably do have a leak)
• check if AC clutch gets engaged
• vacuum the system to get rid of a possible moisture
• fill in nitrogen again, check if the pressure on hi & low side, if everything goes well then
• fill in R134

I wouldn't fill a refrigerant into a system of unknown condition. Just my 3 cents.
Oh, and the most common leaks: HT6 compressor, seem to have the problem by design and condenser.

 

I have checked whith a person sitting inside the car and have her turn the AC switch to max AC, but i can not see that the compressor is kicking in.. So that is a problem.
I suppose when the AC is turned on the AC compressor should engane and not just spin freely?

 

Going by your last sentence, yes, the clutch on the compressor needs to engage so that the compressor can rotate and the AC system can work.

 

I'd say most common spot is the compressor itself. It is a two piece body with a big oring. After many cycles of flexing, it leaks. Buy the Sanden style replacement once you confirm it is the compressor that is leaking.

Your compressor, leaking or not, will not engage if there is no refridgerant in the system. There is a pressure switch that must sense a minimum pressure before the computer will command the a/c clutch to cycle on.

 

Good advice and I would concur about the likely leak source being the compressor itself.

BTW When I did my repair, in addition to having a leak from my compressor as evidenced by oil on the topside of the AC compressor bracket that is directly under the compressor, I found that the expansion orifice at the evaporator was plugged. With it plugged and still some refrigerant in the system, there was no flow of the refrigerant and of course no refrigerant could flow through the orifice to expand and create a cold gas in the evaporator.

 

I was sure that the compressor would engage even if there is/was no refridgerant in the system.
I was not aware of the fact of the pressure switch that must sense a minimum pressure before the computer will command the a/c clutch to cycle on.

Where on the AC system is this switch located?

The first thing i will do is to check if there is any and enough refridgerant in the system. From what i can read from a label on the evaporator hosuing it says the there is supposed to be 1 LB, 12 OZ or in european measureement 0,79 kg of A34 A refridgerant on my 1999 Blazer ZR2
Not really much refridgerant i think

I have a 1964 Corvette StingRay sports Coupe with factory option C60/AC (one of very few 1963-67 Corvettes that came with the factory AC)
The compressor for my Corvette is out of the car for the moment and the compressor is also from a newer Corvette so perhaps i can check if the connector is the same as on the Blazer?

Any here knows what size and type threads there is where you bolt on the manometer? In case i buy one i mean

 

The low pressure switch is usually on the accumulator which is a silver can of beer looking thing. Not sure on an older truck however.

George