Hard earned money down the drain!!
Senior Member
Joined: Nov 2016
Posts: 157
Likes: 31
From: Georgia
R134a Expansion Valve Adjustment
This is the method I used on the other S1, it worked fine, I found this on the Forum in the archives:
“The expansion valve in the systems that use the A6 compressor can be adjusted to make freezing air from R134a. Because the R134a molecule is 55% the size of the R12 molecule, it requires a smaller orifice. That can be achieved by removing the expansion valve and turning the Allen screw inside the evaporator end, of the valve, in about 2 turns. This furthers restricts the pintle movement, thus effectively reducing orifice size. Normally a correct adjustment, for R12 valve, would have 3 threads showing before the screw. I’ve tried it on several R134a conversions and it works every time. Just be sure the pressures are correct.”
Still looking through large pile of car receipts for the part number of the piece that adapts the expansion valve on the Jag that uses the flare fitting to a screw on type valve. If I cannot find it I will call and get the number and then post it and a picture.
“The expansion valve in the systems that use the A6 compressor can be adjusted to make freezing air from R134a. Because the R134a molecule is 55% the size of the R12 molecule, it requires a smaller orifice. That can be achieved by removing the expansion valve and turning the Allen screw inside the evaporator end, of the valve, in about 2 turns. This furthers restricts the pintle movement, thus effectively reducing orifice size. Normally a correct adjustment, for R12 valve, would have 3 threads showing before the screw. I’ve tried it on several R134a conversions and it works every time. Just be sure the pressures are correct.”
Still looking through large pile of car receipts for the part number of the piece that adapts the expansion valve on the Jag that uses the flare fitting to a screw on type valve. If I cannot find it I will call and get the number and then post it and a picture.
If your system has been converted to r134a and the expansion valve HAS NOT been changed I have found it helpful to do 2 things. 1. adjust the 7/32 allen on the outlet of the valve 7 turns out. r12 was usually adjusted about 3.5 turns so it best to wind it in and then wind it back out. 2. use about 80% of the recommended charge for r12. Typical is about 2.8 lbs so 2.0-2.1 r134a is good.
Veteran Member
Joined: Jun 2012
Posts: 1,336
Likes: 344
From: Glendora, CA USA
Expansion valve and flare to thread adapter
Had to call the AC shop for current part numbers and sources:
Expansion valve is from Global Products: GPD3411238.
Adapter is from Santech, phone 817-589-1212: Part number MT1496 - flare to threads.
Hope this helps... these products are sold by various firms.
They work fine in my S1 XJ and have been in there since 2/10/16.
Expansion valve is from Global Products: GPD3411238.
Adapter is from Santech, phone 817-589-1212: Part number MT1496 - flare to threads.
Hope this helps... these products are sold by various firms.
They work fine in my S1 XJ and have been in there since 2/10/16.
Thread
Thread Starter
Forum
Replies
Last Post
orangeblossom
XJS ( X27 )
21
Jan 14, 2017 09:03 AM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)