tried a few searches came up empty for what i am looking for, the problem i am having is i installed a used ac system, all but the condensor which is used from orginal motor, used compressor and lines, accumlator is new though, the problem i am having is i am getting hi pressure on the low side... reading like 120 when it should be around 40 to 45.. i did a complete flush of lines and condensor when everything was off truck, now the condensor is the same one when i had the v6 which motor is now a v8 ... anyway any help would be great as i hadnt figured out the problem as of yet ... TIA

 

did you forget to put the orfice tube in the line????the orfice is what dictates the drop in refrig pressure, I'd check that first.BTW what are the high side readings??

 

yeah, after checking and double checking and blowing through lines, condensor and evap, i figured it must be in the tune, i jumped the low end pressure switch to make sure the compressor kicked on well one fan came on.. so basically when you turn your ac on one fan kicks on in my case both my fans only kick on when motor temps are reached... so i take it this has to be in the tune ( right)

 

If I am reading you correctly, you have one fan all the time and 2 fans when the motor warms up? Even if you have only one fan that would not cause the pressure to go from 40# to 120#. Too much freon will cause high pressure readings, but it would take a whole lot to get to 120# on the low side.

I'm with Bigbadwolf. Sounds like an orifice tube problem. Do you have a dual gauge setup? What is the high side reading?

 

I do not recommend turning that system on until the right amount of freon is in there. 120 on the low = 450-500 on the high side, NOT GOOD. that = a smoked compressor. It sounds like something is mechanically backwards.

Damn thats alot of Freon.