What is the correct low and high pressure reading for a "88" a/c system that has been converted from R12 to R134a? Have gages but dont know what they should read.

 

Sorry I dont have an answer but I'd like to know more about the cost and process of conversion. How long did it take as well???

 

Low side presure would be ok when in the 25 to 35-40 range. Engine running at fast idle (1500 rpm). High side will vary a lot depending on how hot the air temp is at the time you take the reading. 250 to 350 would be ok. Output air temp inside (settings - full cold, high fan, max a/c) should reach 50 or better. Is the system cooling ok or do you think you have a problem? If so give me the pressures you are getting with system running as described above and I will try to help.

 

60 low
350 high.

80 degree weather.

0. get someone to drain the old r-12
1. Remove the bike tire like valve stem from the low side inlet.
2. Add new R-134A conversions oil.
3. Add R-134A oil.
4. Screw on Low side pressure inlet quick release
5. Screw on High side pressure inlet.
6. Charge System.

It will take allot of R-134A.

Make sure your fan clucth is good.
( spend the fan and if it moves more than an inch after you let go of the fan then the fan is bad )

Make sure you have your fan cover on. ( It really makes the difference.

That is it.

Allot of people say that you should remove the old r_12 oil. By breaking the seals to drain the oil, you will have to replace the o-rings.

Also I have read that leaving the R-12 OIL will help better lube the lines and keep the r_134A from leaking out ( RUMOR ).

I have had my A/C running for a month now and it is colder than the north pole. I check the temp coming from the vents and it is around 40 degress.

I wrapped the lowside with sound insulatiuon and alumin tape.

WHY:
R-134A boils a -15, and the engine is almost next to these lines giving off some 200 degress of hot motor.

By covering the lines the lines are able to keep cooler.

MAKE SURE YOU DO NOT COVER UP THE HIGH SIDE... YOU WANT AS MUCH HEAT COMING OUT OF IT....

see when you compress gas back to liquids it creates heat.... When you expand liquid to gas it becomes very cold....

Good luck.....

 

Does anyone know how much R134 and oil goes into a 1986 F-150? My truck was missing the compressor when I bought it, and I would like to convert it over to R134 when I install the new compressor & accumulator.

 

cpgorman your system should hold around 4-5lbs of freon and 6-8ounces of oil.Dont forget to change orifice in high side line by firewall and since compressor was missing it was probably locked up and could've contaminated system with metal shavings etc..and also clean and vacuum system down before oiling or charging system. Hope I could help. Later windsor.