A/C problem (1988 Dodge Dakota)

Reply

  #1  
Old 08-19-06, 01:02 PM
Member
Thread Starter
Join Date: Oct 2004
Posts: 86
A/C problem (1988 Dodge Dakota)

I had my 1988 Dodge Dakota retrofitted and charged at a local automotive shop. The a/c worked great for two weeks. At first I thought that the charge had leaked out, when it quit blowing cold air. I took it back to the shop and was told that the Expansion valve was bad, and would solve my problem. I decided to do the job myself. Same results, sometimes it blows cold and sometimes it doesn't. If I tap on the hose coming out of the valve, it engages the compressor, therefore blows cold air. If I feel the expansion valve the Block is ice cold, but the hose is warm. Is there a way to adjust this valve? Do I have a other problem? Could it be a hose? Any comments welcome. TY
 
Sponsored Links
  #2  
Old 08-19-06, 05:52 PM
Member
Join Date: Jan 2005
Location: Sterling Heights
Posts: 308
TY,
Did you inspect the old expansion valve? Was it dirty or contaminated? It's possible whatever caused the old expansion valve to fail might be causing the same problem in the new valve.

Did the shop that did the retrofit flush out the old mineral oil or did they just put new oil in the system? If they didn't flush; maybe they accidentally used PAG instead of POE. PAG oil will react with the R-12 mineral oil and create a black, tar like mix that will clog the expansion valve.

IMO, anytime you do a retrofit from R-12 to R-134a the system must be flushed to remove all traces of mineral oil and then POE should be used to replace the oil in the system. The system will cool better and, if at a later date someone accidentally adds a few ounces of PAG, it won't be a problem. Add that few ounces of PAG to an R-134a system that still has mineral oil in it and the system will run a few hours and then clog up.....

I have a feeling your compressor is cycling off on high pressure but without pressure readings there’s no way to know!
Good luck,
Phil
 
  #3  
Old 08-20-06, 03:11 PM
Member
Thread Starter
Join Date: Oct 2004
Posts: 86
Yes, they reclaimed the 134 and flushed it out, then charged it. their was some rust colored residue on the lower portion of the valve, where you can visualize the needle inside of the valve. I am wondering if the evaporator is corroding from the inside and causing the restriction. If so, how hard is it to change the evap? Its an 88' Dodge Dakota 3.9.
 
  #4  
Old 08-25-06, 03:39 PM
Member
Thread Starter
Join Date: Oct 2004
Posts: 86
have a feeling your compressor is cycling off on high pressure but without pressure readings there’s no way to know!
Good luck,
What excactly would it mean it the comp. is cycling off on high press?

could it be the drier/receiver? Again/ when i tap on the metal pipe after the valve, the comp. turns on.
 
  #5  
Old 08-26-06, 08:05 PM
Member
Thread Starter
Join Date: Oct 2004
Posts: 86
?????????????????????????

What excactly would it mean it the comp. is cycling off on high press?

could it be the drier/receiver? Again/ when i tap on the metal pipe after the valve, the comp. turns on.
 

Last edited by twelvepole; 08-27-06 at 11:13 AM. Reason: ????????????????????????? Not a real question. Restated the question.
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes