recharging a/c

If your R-134 is gone, you most likely have a leak in the system. The leak will need to be fixed, and the system evacuated to remove moisture before you can recharge it.

Evacuation involves hooking the system to a vacuum pump to place the system in a vacuum. This causes moisture in the system to boil into vapor and exit the system. This process is critical as moisture mixes with refrigerant to create acid, which will wear out your parts.

After this is done you can add more refrigerant. The factory manuals should lay out the process. If you can get ahold of the equipment you can do it yourself.

If you want to do it youself, WalMart has a few different A/C recharge kits. They have additional 134 refrigerant as well. Tools cost from 10 to 20$, and refrigerant costs 5-10$ depending on bottle size. But first try to shop around, how much may it cost in a garages around. I have seen some coupons with local workshops who offered complete AC system check for 25$.

Wal-Mart does not carry refrigeration reclamation units, vacuum pumps, refrigerant gauges, or refrigerant scales to my knowledge (any large scale capable of measuring hundredths of an ounce will work fine.). Specialty supply houses like Johnstone Supply do carry them though.

Define "cuts off". What exactly is happening?

The clutch should kick on and off periodically while driving. The compressor has to turn at a constant rate for optimum performance, so you get different results at idle vs. 3k on the tach. The system compensates for this by engaging and disengaging the clutch.

So it disengages while you are driving and won't re-engage until you come to a stop?

On our 97 -- after recharging it, the clutch kicks in, but then the belt slips momentarily, and then spins the pump... The belt is most definately properly adjusted...

bad pump? I have an A/C pressure guage, and it doesn't show it to be over charged.

sorry for the late reply. but at 3k shouldn't the air be colder than idle? lets say 600 rpm. because the compressor is running faster. also do you know which device is the one that energizes the clutch?

Yes that is true. My old jeep for example, the A/C seemed to work its best around 2000rpm. I was only able to get that speed on the engine on the highway, so around town I had to run in a lower gear to keep the engine speed up.

If you are stuck in slow traffic, put the car in neutral and speed up the engine a bit to get better cooling. This will also help the engine not to overheat.

The compressor clutch is electromagnetic. It engages the compressor shaft to the pulley.