A/C

[midwestLTD]

Ok here is the problem..I 've put a new A/C compressor & evp.tank all new rings..Switched it over,fully charged high & low side no leaks..When driving down the road comp. kicks on and off drags the motor down allittle and is'nt as cold as it should be because of the comp..When sitting at a idle it runs fine it holds it's own and it is cold as hell..What give??Any takers...Don

[Lincolnmania]

have any idea what the low side and high side pressures are?
did you put a new orfice tube in the new evaporator?

[midwestLTD]

Yes new tube..I can't rememeber I had a buddy at work who is in the HVAC biss. on the side . He put his gauges on. He said everthing looked good no over or under charges.Held pressure.....Don

[Lincolnmania]

how much ester oil did you put in the system?

[87vicFIVEO]

Sounds like you overcharged it, I'm assuming your system is 134a now....did you use 80% of the required R12 charge? Should be around 2lbs 13oz's...

When your cruising the compressor is spinning faster and having to much pressure can reduce cooling.

If you want it done right take it to a shop and have them evacuate the system (get all the air out with a vacuum pump) and charge it.

[midwestLTD]

I had it evaced before I installed it..I put 4 cans @ 12 ounches ec. and yes I think I put the right amount of oil in it..What came with the kit as well with the 134a..It staied cold today on the way home from work..It was 95~here today.@ A 20 mile drive..

[gadget73]

The low side pressure on an R134 system is normally lower than R12. You might need to adjust the pressure switch a little. Normal cutoff for R12 is 25 psi, you want about 21 for r134. Unplug the electrical connector on the pressure switch, and back the phillips head screw in there out 1/4 turn. That should put it about 20-21 psi cutout on the low side. Also remember, the outside temperature affects the pressure. Hotter outside means higher pressure, so you might have the system a tad bit undercharged for cooler temps, but when its 90+, the pressure is enough to keep it ticking along. Really to find out exactly whats going on, you need to get the high and low side pressures checked along with the outside air temperature to see if all the numbers crunch properly.

Another thing I've learned, the slower the fan speed, the more it cycles. Mine will cycle like that when its not really hot outside, and my ATC kicks the fan down to low. iSometimes, it will actually freeze the evaporator up, and the compressor cycles very rapidly. Turning the fan to high to move more air through the evaporator keeps it from icing, and it helps keep the compressor running more normally.

[midwestLTD]

Thanks Gadget I'll try that..When it is cool ouy\tside my A/C gets frezzing which I like..When It's hotter it does a good job. Just fluxuates every now & then when running down the road..See if your advise worksthank's again...Don

[Chris84]

ehm, so, a very stupid question from me...

where is the filler for the low pressure line?
i only knew this thing on the compressor...
iīm planning to fill my A/C, but i donīt know where the fillers are...
i had to change nothing, because in Austria theīve got R12 in the shops

thanks
chris

[gadget73]

On the black can on the right side of the engine bay.

[Chris84]

thanks
it looks like new. no one ever opened this cap before, thereīs still paint on top of the cap