A/C pressure

[BillyP]

I just replaced the a/c compressor, drier and orifice tube on my '94.5 250 (had to go with an 8 groove '95 compressor though) and was wondering if anyone knew what the gauges were supposed to read on the high side when filling up, everything kicks in but got up to 350psi on the gauge not even finishing with the first can, and I stopped feeling that was too high a reading, any ideas on this?

Thanks in advance.

[eagledieselmedic]

I do not have the psi memorized. It is, however, affected but the ambient (outside air) temperature.

I do know that 350 on the high side is way to high. In 95 F temps and the a/c on max with the doors open you should only have about 250-275 on the high side (red connector usually) and around 45 to 55 psi on the low (blue connector).

If you have a full gauge set it should have the psi ranges and ambient temps listed with it.

Remember when you refill the system after being open to the air you should have a vaccum placed on it to eliminate all moisture in the lines. Also it should be filled with 134 and lubricant in the proper amounts.

Larry

[MrJohnWayne]

Larry is right..

high side you want around 250, low side no lower than 38

[TODDC]

Did you flush the system and than evac it down? Also was the O.T. put in the right way? There is an arrow on it showing the direction of flow. Sounds like a blockage. Should take 3 cans if using the 12 oz ones? Readings are being taken at 1500 rpm? The first can, just let it go in to the system on its own before starting the truck. After that than start the truck. Jumper the low pressure switch to let the refrigerant be pulled in when adding the remainder cans. Also. Did you drain the drier and see how much was in it. This has to be added to the new one plus a little extra. If not, you will not have enough oil in the system and cause problems. Did you add oil the the compressor and spin it over to get in inside of it too? Just some stuff to confirm on so no damage will be done to it. Was any kind of sealer/fixall in a can added to the system before it was repaired? This is a major NO NO and will kill a compressor early.

[BillyP]

Well, turns out the new orifice tube I bought goes in with the color DOWN instead of the way the original one came out which was color UP. Very cold air now, working like a charm. Sitting around 230 on the high side, about 40 on the low side.

Thanks for all the help.