R134 Air Conditioning Help

[AB TY 752]

I have had trouble with my a/c since i bought my truck. It has r-12 in it then but i converted it when it started blowing hot. I have replaced the compressor several times-all of whick were due to leaks around the compressor seals.the dryer and orifice tube was replaced during each compressor install. I have flushed the system during one of these repairs. Charged the system and checked for leaks. My high side pressure is around 450-500 psi-way too high!!! The low side pressure is about 125-150 psi-too high also!!! All of these high pressures are smoking my compressors. I was hoping some of you guys with front mount i/c have seen something like this. The clutch fan doesn't seem to help with cooling the air over the condensor and neither do electric fans. Is my problem just an air flow issue? Or does it sound like there is something else going on? Any input, even sarcastic, helps. Tahnks!

 

[Ratfink749]

Re: Guys with front mount ic please help

Re: Guys with front mount ic please help

High pressures are usually an indicator of either being over charged, or restrictions in the system. Restrictions are usually either high side or low side, not usually both. When converting to r134 was there a revised refrigerant capacity? I've never done a conversion so I don't really have any over ideas besides that at this point.

 

[silverblaz]

Re: Guys with front mount ic please help

Re: Guys with front mount ic please help

When we retro fit R12 systems to R134 you have to make sure you charge them to 80 % or what the R12 charge was so example 1lb of r12 would be .8 lbs of r134

 

[Ratfink749]

Re: Guys with front mount ic please help

Re: Guys with front mount ic please help

Ahh that would definately explain the overly high pressures then if it was charged to the original r12 ammount.

 

[dgoodhue]

Re: R134 Air Conditioning Help

Changed the topic of thread to be more consistent with thread subject..

 

[AB TY 752]

Re: R134 Air Conditioning Help

Tahnks for the input. I have charged the system to the proper amount-80% of the r-12 amount. Performed vacuum. I have even handed this problem to a couple of a/c guy here in my shop. They are stumped also. This is why i was wondering if this is a common problem when running a front mount i/c, or if i am the only one on the forum who is having trouble.
Like i said before going from fan clutch to elec.fans did not seem to help much. Anyone have any other ideas?

 

[Foot Performance]

Re: R134 Air Conditioning Help

get a really high air flow fan(like a shop fan) and put in on the truck to see if pressures go down. if it it does the fornt mount is causeing air flow problems

if not

I would pull 1/2 pound of freon and see what happens and keep doing it till the pressures are good

80% is more of a guide

you should come to tulsa next weekend and I will bring my guages and see what I can do
http://www.syty.net/forums/showthread.php?t=69724