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High pressure very high

bmiszuk on Sat September 01, 2012 3:40 PM User is offline

Year: 1998
Make: Honda
Model: Civic
Refrigerant Type: R134
Ambient Temp: 95
Pressure Low: 25
Pressure High: 450

My daughter had her condenser replaced and the system evacuated and charged. It worked fine for a few weeks but lately cooling is poor. I connected gauges and ran the RPM's up to 2,000+ with a fan blowing on the condensor. Over maybe 30 seconds the high side crept up from 350 to 450psi.

What should I do? The shop she took it to didn't seem to really know A/C so I don't want to take it back there, but what I don't understand is why it worked well for a while and now isn't.

Dougflas on Sat September 01, 2012 4:24 PM User is offline

Mist a water hose on the condenser. If the high side drops dramatically, the cooling fan may be bad. You will have an air flow problem.

bmiszuk on Sat September 01, 2012 4:41 PM User is offline

Okay I tried that. First I pulled it out of the garage (it's cooler outside). Pressures were 25/325 sitting outside.

Spraying water on the condenser got me 12-15psi and 175psi.

I noticed the high side shrader valve is leaking too.

mk378 on Sat September 01, 2012 5:36 PM User is offline

I think that car has two fans on the radiator / condenser assembly. Both should start immediately when you press the A/C button.

Edited: Sat September 01, 2012 at 5:38 PM by mk378

bmiszuk on Sat September 01, 2012 5:48 PM User is offline

The condenser fan runs constantly. The radiator fan cycles on and off.

mk378 on Sat September 01, 2012 6:18 PM User is offline

Oh, for a 1998 that is right. I thought it was a 1988. On the 1992 up to 2000 with the half-sized condenser, the fins on the bottom part of the condenser are prone to get munched up by rocks, etc. from the road, which will impair performance. Still it is odd that it worked for a while then something went wrong by itself.

Edited: Sat September 01, 2012 at 6:21 PM by mk378

efxengr on Sat September 01, 2012 11:34 PM User is offline

Did they also change the acumulator/dryer? Can you confirm correct condenser?

I had a late 90's civic do something similar and the TX valve wasnt opening up. At 14 years may not be a bad idea to replace. I think mine was a capillary/bulb type. You might ask the shop if they weighed the charge (or used a machine) or did they charge with gauges only.

TRB on Sun September 02, 2012 1:13 AM User is offlineView users profile

When it worked for the few weeks after the repair was the ambient temperature the same as it is now? No additional refrigerant has been added since the repair?


When considering your next auto A/C purchase, please consider the site that supports you:

bmiszuk on Sun September 02, 2012 9:01 AM User is offline

I believe that crazy high side pressure was because by insufficient airflow when I was testing in the garage. After I started working outside I never saw that again.

The high side shrader valve is leaking like crazy. You can actually see it bubbling out. The high side cap has no o-ring in it. Yesterday I added a little more freon and my daughter reported vent temps of 40-45 degrees on the highway (outside temp was around 90).

I'm waiting on a shrader valve tool and electronic scale to arrive. Then I'm going to change the valves, vacuum it and charge by weight so I know it's charged right.

Efxenger, they did not change the accumulator/dryer. You think I should do that before I put it all back together?

mk378 on Sun September 02, 2012 9:39 AM User is offline

A good cap with an o-ring should hold the refrigerant in. Shrader valves seldom seal perfectly, that's why the cap has an o-ring.

If you're going to open it, definitely change the drier.

efxengr on Sun September 02, 2012 12:22 PM User is offline

yep, change the drier....and for about 6 bucs more pick up an 0-ring/gasket set for that car model. It may have one for that cap (although you can get a replacement cap w/o-ring) but you may want to back track on the condenser connection in case the shop didnt put new 0-rings on when they changed it.. The drier may or may not have them but also you'll have them in case you need to go back in.

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