YACACT: Expansion valve bad?

[Shawn]

When the compressor is running the low side pressure drops down to 15psi and the high side goes up to 225. When I turn off the compressor the low side slowly rises but even after 10min of sitting the low side only goes up to 60 and the high side is around 150 or so. The car is my sister's 2001 civic ex. With my car the pressures even out very quickly. Thoughts?

 

[Shawn]

bump for edit

 

[Lounatik]

Sounds like you are low on freon. Low side is usually what, 75-80 on a car? The high side is going to be in the 260 range,IIRC. If you are low on gas, then you will get the readings you describe. Check the little sight glass on the accumulator and see if you have bubble in the gas.


Peace

Lounatik

 

[drnickriviera]

Can't use the sight glass on 134. Only R-12 systems.

Is it blowing any cold air? Is the low side line cold? Not sure what's going on. The pressures should equalize fairly quick.

 

[Lounatik]

Originally posted by: drnickriviera
Can't use the sight glass on 134. Only R-12 systems.

Is it blowing any cold air? Is the low side line cold? Not sure what's going on. The pressures should equalize fairly quick.

Really? I havent worked on a car system in forever. Well before the 134 days. Call me Mr. Dumbass. Sorry!

 

[Rubycon]

Spatiotemporal implosions are detectable with a non interfering piezoelectric transducer and simple op amp shaper. It's basically an electronic sight glass that can pick up bubbles inside the liquid line run before the metering device.

Have you checked the R134a TP chart and measured the superheat?

 

[Zach]

Originally posted by: MS Dawn
Spatiotemporal implosions are detectable with a non antiinterfering piezoelectric transducer and simple op amp shaper. It's basically an electronic sight glass that can pick up bubbles inside the liquid line run before the metering device.

Have you checked the R134a TP chart and measured the superheat?

Fixed.

 

[Shawn]

Originally posted by: drnickriviera
Can't use the sight glass on 134. Only R-12 systems.

Is it blowing any cold air? Is the low side line cold? Not sure what's going on. The pressures should equalize fairly quick.

No, it's not blowing any cold air but the compressor is running. Doesn't seem to cut out or anything. Very weird. I had added a can of r134a a while back but IIRC the low side pressure was still low but the compressor started making a whining sound. I didn't have a high side gauge then but I assumed that there was too much pressure on the high side so I let some back out. It didn't seem to blow cold air after I had added a can either. Maybe a little but the compressor whine concerned me so I decided not to add anymore and I let some out.

Since then I have bought real gauges and an AC vac since I do all the AC work on my car. Think I should let it all out and run vacuum on it and try to re-add the right amount? I don't want to waste the freon though if there is something else wrong.

 

[drnickriviera]

I almost had sticker shock when I bought a can of 134 a couple weeks ago. I remember when it was $3-$4/can now it's $10. I guess one thing to do is find an empty 30lb can and put it in a bucket of ice to pull the 134 out of the car. That way you could weigh it to see how much was in the system w/o going to the expense of buying cans to recharge it, but you'll have to do some jerry rigging to adapt from the fittings on the bottle to the ones 134 uses.