Problems recharging A/C

[andpol]

My A/C was working earlier this year, with a noticeable increase in engine RPM when turned on vs. off. Currently, I do not see that happen. After searching for and reading through many A/C threads, I went and bought a RedTek recharge kit and filled it up to the indicated medium-range on the gauge (about 45 psi). While recharging, I noticed that the compressor started working again and the air coming into the cabin seemed to be cold! After turning off the engine and removing the recharge kit, I heard faint hissing coming from the engine which smelt like the refrigerant. After some poking around and feeling, I determined the source of the noise to be some sort of valve (circled in the picture below). If I put my finger on top of the hole, the hissing stopped. The air conditioning worked for several more hours before all the refrigerant leaked out. What is this valve? Is something supposed to be attached to it? Why is it leaking?




Thanks!

[Mr. Flibble]

I don't know why it is leaking, but I think that is your high-side AC port. You were no doubt filling at the low side (you are supposed to).

[andpol]

Yeah, I'm pretty sure I charged it correctly, from the green cap with an "L". I don't think the red-circled location is the high pressure A/C port though...I have a feeling that one had a black cap with an "H" on it (not pictured here), also I think it may have been a schrader valve as well?

[thelazygreenfox]

Andpol
it's time to replace both the high and lo side fittings. Interesting you were able to mate up the fittings when you recharged.

Most DIY kits are supplied with fittings to mate up with their own recharge hoses. Japanese fittings usually don't mate with NA fittings. Was the system previously recharged?

Run the compressor every week or so to keep the o rings etc. lubricated. If the system discharges again you may need to have parts replaced.

TLGF

[Diver]

I think the part you have circled is the compressor over pressure relief valve. It's not the low or high filling ports (and they are standard and specific to R134a gas worldwide) so i'm sure they're fine.
I would say that either: a) The valve is functioning correctly and filling via a can has allowed too much pressure to enter the system, or b) The valve is faulty allowing gas to escape.
When it stopped hissing had ALL the refridgerant leaked out? i.e. has the AC stopped functioning now?

[andpol]

Diver,

...I think you've figured it out exactly what it is! A quick Google image search results in little screw on valves that look very similar.
Most of the refrigerant had leaked out and the AC has stopped functioning completely. Pressing the AC on/off button in the cabin has no effect on the engine RPMs whatsoever and I can't tell any temperature difference (PS. I've checked fuses in the engine, under the steering wheel, and behind the glovebox, and it did work immediately after my recharge attempt so it's simply a pressure problem).


This is great news! I'm sure they're pretty cheap, and it looks very easy to replace

Now, I'm going to do some research looking into if there's different pressure specifications, in case anybody knows the rated PSI or compatible part number, please let me know.


Thanks Diver!!! You've made my day!

[andpol]

Update:

I've got my A/C working! I took a risk and ordered a relief valve for the MSC090 compressor (the L400 seems to have an MSC130CV as far as I can tell). It's been 3 days after replacing the valve and recharging with a RedTek kit, and A/C seems to be working fine.

You can purchase the part here (only place that I found):
http://www.autozone.com/autozone/access ... id=1486200

Shipping ended up being $20 into Canada + $7 for the valve itself, I'm happy I didn't need to buy a whole new compressor.

In case the link ends up going away, for future reference:
Part Number: MT1611
Thread: 3/8 inch - 28 TPI

Pics (original on top):


As you may have noticed, the O-ring style is a little bit different. The new one has a slight bevel, but like I said, it's been holding for 3 days so far...