R134 Expansion Valve?
06-14-2013, 01:44 PM
#1
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R134 Expansion Valve?
Hi all, is there a difference in an expansion valve for R134 and R12 ?
I'm working on my 86.5 w/rear AC and converting it to R134a (system was empty had to repair Low side tubing). Ran the Vacuum pump (3cfm) and it held vacuum over night on both Hi and Low side, now rear AC works but front AC blows warm/cool (heater core completely disconnected)
I've read there is a difference and wondering if I got an R12 valve in the front as I replace both valves along all w/ O rings and the front Valve does not seem to get cold like the rear one does.
If there is, can it be adjusted? Can I have a new out of box failure?
Thank you!
Dave
I'm working on my 86.5 w/rear AC and converting it to R134a (system was empty had to repair Low side tubing). Ran the Vacuum pump (3cfm) and it held vacuum over night on both Hi and Low side, now rear AC works but front AC blows warm/cool (heater core completely disconnected)
I've read there is a difference and wondering if I got an R12 valve in the front as I replace both valves along all w/ O rings and the front Valve does not seem to get cold like the rear one does.
If there is, can it be adjusted? Can I have a new out of box failure?
Thank you!
Dave
06-14-2013, 02:52 PM
#2
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All the expansion valves we receive now say R134a. Fitted and sold hundreds of them on R12 systems with zero issues. Technically there is a difference but a minor issue. I can't get R12 ones.
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Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
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928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
06-14-2013, 03:10 PM
#4
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It would be possible to get an out of the box failure of course - can't remember any returns at all.
Is your recirculation flap closed up against the bulkhead?
Is your recirculation flap closed up against the bulkhead?
06-14-2013, 05:27 PM
#5
Chronic Tool Dropper
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Dave-
Greg Brown posted a note a year or so ago regarding fialing blend door seals. So start at the temp setting motor and make sure it's trying to block the passage through the heater. Then look for leakage in the box where the door deals have gone away.
Of course, there's still the basic stuff, like finding the evap temp vs the low-side pressure to see if it is cold internally and gets warmed by bypass air, vs the higher low-side pressure that means it just doesn't ever get cold enough. The gauges tell a whole lot about what's going on in the system.
Greg Brown posted a note a year or so ago regarding fialing blend door seals. So start at the temp setting motor and make sure it's trying to block the passage through the heater. Then look for leakage in the box where the door deals have gone away.
Of course, there's still the basic stuff, like finding the evap temp vs the low-side pressure to see if it is cold internally and gets warmed by bypass air, vs the higher low-side pressure that means it just doesn't ever get cold enough. The gauges tell a whole lot about what's going on in the system.
