[lucy1983]

I have a 1997 freightliner the ac compressor has been replaced twice this month, we replaced it ourself, I have done a vacume, replaced all the old parts, etc. the compressor blows the freon out I don't know what I am doing wrong, I seem to think that the pulley is not lined right but the pulley was sold to me by the dealer, please help

[TxGreaseMonkey]

Begin by leak testing the system. Specifically identify the source(s) of the leak. The link below may help:

https://www.askmehelpdesk.com/cars-t...ml#post1864159


Questions and thoughts:

. Did you change the accumulator/drier and orifice tube? If you didn't, there may be debris from a failed compressor, or something else, restricting the orifice tube. Also, ensure the condenser is not restricted by blowing air through it.
. Do you know what the low side gauge and high side gauge pressures are supposed to be, what the system's refrigerant capacity is, and what the system's refrigerant oil capacity is?
. Did you add too much freon? It needs to be carefully weighed.
. Did you only add freon to the low side?
. Were the static and performance pressures within specifications, after you checked the system?
. Did you add the proper amount of PAG oil to the compressor's suction port?
. Did you replace ALL O-rings and coat them with PAG oil?
. Did you ensure all fittings are tight and hoses are in good shape?


This link covers my experience, in April of this year, when I replaced the compressor, accumulator, and orifice tube on my Taurus:

https://www.askmehelpdesk.com/cars-t...ml#post1722090

It may be instructional. This has been the hotest summer in Texas' history and the A/C has worked flawlessly.

[davidcasarez]

A little late to help this person but, to answer your first question. It sounds like "the compressor is blowing out Freon" is because you've overcharged your system. The compressor has a pressure relieve valve behind it that will release Freon if it is over-pressure. This will cause it not to cool (being over charged)! Next as far as your pulley not lining up is because the mounting brackets for the stand up compressors on these Freightliners are notorious for wearing the mounting holes oblong. If you insert some spacers (washers) between the Bracket and the engine where the bracket mounts you'll see everything straiten out pretty close in alignment. You'll need some Gauges to check everything out but you should have about 30psi to 50 psi on the low pressure side (depending on ambient temp) and 250psi to 350psi on highside. Good luck I have a 99' Freightliner and I like to fix it myself too!

[davidcasarez]

Also forgot to add, This system uses 2 expansion valves. 1 behind the air filter (you need to remove to see or access) and another one under the passenger side sleeper bunk.