[mitch968]

I have a 92 that has already been converted to R134. The AC was charged by my shop and working great last summer, but now hardly at all. I decided to try out one of those do-it-yourself kits from Autozone that includes the hose and gauge with charge and oil all in one can.



I initially tried to test the pressure with the gauge, but it was reading zero. I tried detaching and reattaching the gauge, but no difference. I decided to go ahead and charge and as soon as I released the gas the gauge reading was in the red, so I quickly shut off the gas, disconnected and shut the car off. I'm sure I was on the low pressure side down under on the compressor.



After contemplating for a while I started the car and noticed that the AC was cooling very well now. I went back under with the gauge and was still getting a high reading (I think over 50psi), so I leaked a little and now it's back to reading zero. It's still cooling very well, so I don't quite get what's going on here. Maybe a flaky gauge? Some questions for the AC gurus out there...



How likely is it that I actually have an overcharge situation and what could happen if I run the compressor? What pressure should I be seeing at the low fitting? Would the AC actually still be cooling well if it was significantly overcharged? Does the compressor have a switch that shuts it off under excessive pressure? I've tried bleeding some more from the valve, but nothing is released. Is it possible that the reading was artifically high at the low port due to the charge not being taken in fast enough?



I'd like to start using the AC tomorrow, but I don't want to damage anything. Any ideas?



Thanks in advance.

-Mitch

Partial Post: Please Login or Register to read the full post.

[TonyBray]

Mitch,



I just charged my 94 with what sounds like the same stuff. Mine was so low that the compressor wouldn't even engage. I connected to the low side at the compressor and activated the can of coolant until it wouldn't take any more. Then I turned the engine on and turned the ac on max and went back under the car and reactivated the coolant. I shook the can like the instructions say for about 10 minutes. On the little gauge that came on the can, I mine barely went into the blue from the green section. I never got up any higher on the gauge. I put a digital thermometer in the center vent and got it as cold as 48 deg F.



This was my first time to mess with this stuff and I got the info by searching here.



--Tony

Partial Post: Please Login or Register to read the full post.

[mitch968]

The instructions on my can said to charge with the engine running first. Is that not correct for our cars? Maybe that's why I was seeing wacky pressures?

Partial Post: Please Login or Register to read the full post.

[Lemming]

[quote name='mitch968' date='May 30 2006, 08:07 AM']The instructions on my can said to charge with the engine running first.  Is that not correct for our cars?  Maybe that's why I was seeing wacky pressures?

[right][post="22029"]<{POST_SNAPBACK}>[/post][/right][/quote]



I just charged mine and did it while the car was running and the AC was on high. It took two can to get it charged properly.

Partial Post: Please Login or Register to read the full post.