a/c questions

[90red]

I just recharged my a/c with R-134A and it is fully charged. The compressor does not cycle like it normally should. It will cycle normally when it rains and the air is a little cooler. It is damn cold when it does this. It is not very cold in its current state. Are there any sensors that could cause this? Any help is appreciated. Thanks guys.

90red

 

[RichP]

The book says that if the compressor cycles more than 5 times per minute on HIGH and cold the coolant level is low.

 

[four_shot]

did you measure the amount of refridgerant you used or use the small can method. at a guess Im thinking you may have overcharged it.

 

[RichP]

Hmmm, your name 90Red I hope that if you have a 90XJ and put R134a in it you did the conversion from R12 before hand, they do not mix well.

 

[90red]

Yes, I did the conversion. Put a new drier in it, along with the correct valves. I did not replace the expansion valve because the local Jeep shop said it was not necessary. I also flushed the system. I am thinking that I will probably end up replacing everything just for piece of mind. It wont be cheap, but in Texas I think its worth it. I would like to think that my current set up would work, but for some reason it just wont cool correctly. And yes, I do have a Red 90 XJ. Couldnt think of a better name. I have cleaned the condenser and evaporator so I know that the fins are not clogged. When recharging the system I never let the high side pressure get above 250, and the low side pressure hovered around 40. From what I understand, the high side pressure is not supposed to get above 250. Anything higher can damage the lines. I have replaced the heater control valve so I know that works correctly, the vacuum lines are also intact. The sight glass shows bubbles, but I was also told for R134 there needs to be bubbles because it expands more than the R12. If anybody has any insight, please do not hesitate to contact me. All of your help is greatly appreciated. ROCKS!!!! I have received more help from you guys than I could have ever imagined.

Keep on Keepin' on
90red

 

[RINGKONG]

Yes, I did the conversion. Put a new drier in it, along with the correct valves. I did not replace the expansion valve because the local Jeep shop said it was not necessary. I also flushed the system. I am thinking that I will probably end up replacing everything just for piece of mind. It wont be cheap, but in Texas I think its worth it. I would like to think that my current set up would work, but for some reason it just wont cool correctly. And yes, I do have a Red 90 XJ. Couldnt think of a better name. I have cleaned the condenser and evaporator so I know that the fins are not clogged. When recharging the system I never let the high side pressure get above 250, and the low side pressure hovered around 40. From what I understand, the high side pressure is not supposed to get above 250. Anything higher can damage the lines. I have replaced the heater control valve so I know that works correctly, the vacuum lines are also intact. The sight glass shows bubbles, but I was also told for R134 there needs to be bubbles because it expands more than the R12. If anybody has any insight, please do not hesitate to contact me. All of your help is greatly appreciated. ROCKS!!!! I have received more help from you guys than I could have ever imagined.

Keep on Keepin' on
90red

Where is the sight glass on these saden compressors? probably in an easy spot to see...

 

[ACE]

The sight glass is actually on the drier, at least it is on my '90.

 

[Deyman]

I just had a/c issues on my 97. Be sure to check the wires going to the pressure sensor on the back of the compressor. The dealer told me I needed a new computer. After further inspection by me, one of the wires was broken inside the insulation. A simple splice and it's blowin cold as a mofo. Check all wiring. Good luck.

Deyman

 

[RINGKONG]

The sight glass is actually on the drier, at least it is on my '90.

that explains why I can never find it..

thanks.

 

[four_shot]

witha a 40 psi low side I, Im still kinda wondering about the overcharge. but it sounds like you have access to professional equipment so Its a good possibility that you havent. as a note, you are supposed to use 10% less R134a than R12. I wouldnt go replacing everything. Chances are that there arent any differences between most of the stuff you yank and the stuff you install. the exception being a later model R134a condensor. they are much more efficient than the older R12 units.

 

[Rob Mayercik]

Hmmm, your name 90Red I hope that if you have a 90XJ and put R134a in it you did the conversion from R12 before hand, they do not mix well.

Rich, if by "conversion" you mean more than just pulling a vaccuum on the system, allow me to throw a monkey wrench into your thought process. My recent experience seems to agree with what four_shot is saying:

I just had my '92 changed over from R-12 to R-134a about a month ago. The system had sprung a leak and gone non-functional back in the spring.

Inquiries at the dealer revealed that the better strategy was to see an A/C specialist (their words), so I checked with the local shop, which had done A/C for me in the past on my old Omni.

Took it to him, and as it turned out the condenser (a.k.a. evap core) was shot. Seems the metal fins had all the stiffness of cardboard that was rained on the night before. Other than that, he didn't change any parts. Reportedly (and also according to the invoice), all he did was fix the leak, pull a vaccuum on the system, and fill it back up with the R-134a.

Admittedly, he may have installed the R-134a condenser, since mine was the source of my leak, but when I talked to him on the phone before taking it to him, he said you don't have to do anything except pull a vaccuum before pumping the 134 in.

It blows as cold with the R-134a as it did with the R-12.


YRMV

Rob

 

[RichP]

When I say conversion mostly I was curious if he had removed all the R-12 before just sucking in the R-134a. It is a no-no to mix the two from what I have been told.
I also understand that the dryer needs to be replaced for this or at a minimum the dryer material inside.
I have a problem with mine, over the past 3 years it has had a leak and once a year I end up putting in a small bottle of coolant, that usually gets me thru the summer. This time though it lasted about 4 weeks so the leak has gotten worse and I need to have it fixed. I just hope it's not the parts behind the heater core, that gets expensive.
Luckily this summer has been so wet that I have not really needed the AC.

 

[DeathByXJ]

silly question

I'd pretty much given up on getting the a/c back online on my '90 XJ because of the cost, but the coversion sounds affordable.
Just how much $$ does it take to do the conversion properly? And does 'proplery' mean I have slap in a new dryer and/or another component or two?
Thanks for any help...

 

[Rob Mayercik]

DeathByXJ:

I spent about $600, but that included the condenser.

I'd say look around for a reputable A/C specialist and ask them - they could give you a good idea of what you'd need.


Rich: No argument on not mixzing the two R's. As far as I know I still have my original R-12 Dryer and Material, but I can check my invoice. If you don't mind coming all the way down to my neck of NJ, I can give you the number of the guy who did mine.

Rob

 

[Speed_racer]

right amount of oil? then put the r134 in