recharging a/c

[DCM]

'96 Legacy Brighton wagon 5-speed
air is not cold.
Compressor, etc. seem to be functioning correctly.
Can I recharge myself?
where to purchase 134 refrigerant?
procedure?

TIA

David

 

[Henry Paul]

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.

 

[Guest]

'96 Legacy Brighton wagon 5-speed
air is not cold.
Compressor, etc. seem to be functioning correctly.
Can I recharge myself?
where to purchase 134 refrigerant?
procedure?

TIA

David

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$.

 

[Henry Paul]

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.

 

[Edward Hayes]

From my experience: If the ac is putting out some cold air but, not cold
enough then the system still has a positive pressure and you will not need
to evacuate the system. You can go to most auto parts store and purchase a
recharge kit as mentioned. FOLLOW THE instruction very carefully as you must
charge through the low pressure side. You will have no way of know if your
recharging is complete without gages but I stop when the system is putting
out a reasonable amount of cool air. You do realize that you have a leak so
what you are doing is recharging a leaking system. If you have the $ get it
checked professionally. ed

 

[Shun Ju Hu]

can i ask a question, you guys sound very knowledgable. my 94 legacy's a/c
runs fine at idle. but as soon as the car moves the a/c cuts off. what could
be the problem? thanks --James--

 

[Henry Paul]

Define "cuts off". What exactly is happening?

 

[Shun Ju Hu]

The compressor clutch kicks off, while both coolant fans are still on then
cool air becomes warm. But if i stop the car the compressor comes back on
nice, and cool air comes out again. all this happens when using a/c or max
a/c.

 

[Henry Paul]

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?

 

[Josh Assing]

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.

 

[Shun Ju Hu]

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?

 

[Henry Paul]

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.