AC Pressure's
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AC Pressure's
I have a 93 Ford F250 Diesel which I've recently had some A/C work done on. The mechanic converted my system to R134a and ended up with the following pressures High 280 Low 54. The A/C will only cool down to around 66 degrees at idle with the A/C set on Max. The Temp average is around 92-98 degrees with high humidty here in Texas. What will it take to get these pressure down to a normal level and obtain some better performance from the A/C. Or is this the best that the system will perform. The Mechanic told me that he could probably get the low pressure down if I purchased a new compressor. DO I NEED A NEW COMPRESSOR OR NOT????????? Please help!!!!!!!!!
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Joined: Dec 2001
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From: Louisville,Ky.
AC Pressure's
54 is a bit high for 134A 45 max is recommended. If the system is in good shape, it should get down in the 40 degree range. My 88 Mustang will blow about 38 degrees on max. I would have them check the orfice tube and check for debris. You could have a compressor on the way out. I would also make sure that they vacuumed out the system good to make sure that there was no moisture in the system.
Jimmy
Jimmy
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From: Louisville,Ky.
AC Pressure's
It may be in need of a compressor soon. Our C&^#y Astro van is in the same boat. I have cleaned/changed the orfice tube twice and it keeps getting metal shavings in it. The compressor is coming apart on the inside. It doesn't make any unusual noises, but it wint be long. Even when low on freon, it won't drop below 50psi on the lowside. The compressor is not moving the freon like it should. My guess is thst a new compressor is needed.
Jimmy
Jimmy
Mountain Pass
Joined: Sep 2002
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AC Pressure's
Reasons for high pressures:
1. dirty condensor coil
2. orifice too large thereby suction pressure and consequently high pressure gets too high
3. overcharged
I'd check all of the above or have them checked by a different mechanic before changing the compressor. Don't throw parts at it, have someone eliminate the problem by proper diagnosis.
1. dirty condensor coil
2. orifice too large thereby suction pressure and consequently high pressure gets too high
3. overcharged
I'd check all of the above or have them checked by a different mechanic before changing the compressor. Don't throw parts at it, have someone eliminate the problem by proper diagnosis.
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Post Fiend
Joined: Nov 2002
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From: Memphis, TN
AC Pressure's
2. orifice too SMALL. If the orifice was the same size as the hose (GIANT), the refrigerant would flow freely thru the system and almost NO pressure would build up - it would stay close to what it is with the system off. But if the orifice gets blocked (too small), then the compressor will pump ALL the refrigerant to the high side, and it can never flow back to the low side, so the high side pressure would go SUPER high.
I totally agree about diagnosis before buying parts.
I totally agree about diagnosis before buying parts.
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Mountain Pass
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AC Pressure's
cj, where do you live? I live about 60 miles west of houston. If you are around Houston, I can help you out but you would have to bring the vehicle to my house. If you have air in the system or it is overcharged, your high and low pressure readings will be higher then normal. You are going to need to take the vehicle back to a shop to get this fixed unless you know someone with the tools. The first thing to try is to remove refrigerant until the clutch starts cycling with the engine rpm up around 1500 and normal a/c, high fan. Then slowly add until the compressor quits cycling. If the air is much cooler, it was overcharged. If the air still isn't cooler, you have air in the system.
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