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1995 Isuzu Rodeo

ShaneD on Tue June 10, 2008 12:25 PM User is offline

Year: 1995
Make: Isuzu
Model: Rodeo
Engine Size: 3.2 v6
Refrigerant Type: r134a
Ambient Temp: 90
Pressure Low: 45

I bought a can of 134a and a gauge/dispener attatchment. Yesterday evening, without the engine runnig, I hooked everything up. I got a pressure reading of 105. I started the engine, low side pressure read about 55psi. It dropped a little after engine was idling, but not much. I added refrigerant until the pressure dropped to 45, which, according to the gauge, is right where the blue and orange sections meet on the gauge face, indicating the intersection of operating range and low. My questions are:

1) whhile engine running and ac on high, the more freon that is added, the lower pressure reading you will get, is this right?

2) I have searched, and have found that in general, low side readings should be between 35 and 45psi when system is full of freon, is this correct?

I only used about 1/2 the can. Should I add more freon so the pressure reads 40psi? The ac is blowing way colder air now, so I knew I was pretty low.

Chick on Tue June 10, 2008 3:07 PM User is offlineView users profile

Not to smart to add without knowing BOTH pressures. Those cheap death kits don't tell you that. Lets say your side was 15psi and dropping, most likely your high side would be climbing due to a restriction. In your case, you were lucky this time. No "apparent" damage yet. You really need a set of manifold gages to charge or check your system. You wouldn't get your blood pressure checked with just one number.. Also, the best way to check your system is to evacuate and recharge the system amount into the vacuum, but for topping off like you did, both pressures are needed.. Low side alone really tells you nothing.. It's GOOD to do your own repairs, AC included, but you need to do it right or it can really cost you big time in the long run..Hope this helps..

Email: Chick


Freedoms just another word for nothing left to lose

ShaneD on Tue June 10, 2008 6:04 PM User is offline

Thanks, that does uncle has the gauges. What should my readings be. I've heard high side psi as a general rule should be 2 to 2.5 times outside air temp. Can you give me some insight on my questions? Thanks!!

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