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high and low pressure A/C valves
- Thread starter XJNagle
- Start date
wolfpackjeeper
NAXJA Forum User
- Location
- 500' and 500KCAS, RAF lakenheath
I believe the High pressure side is the one on the block side of the compressor. You also have a 1/4" valve you have to open to get the kit to flow in. That is the way it was on my 1991, which could be a little different
I think the little kit pieces only fit the correct side anyway. However, they are coming with more and more pieces so yours might have 8 little adapters.
I think the little kit pieces only fit the correct side anyway. However, they are coming with more and more pieces so yours might have 8 little adapters.
winterbeater
NAXJA Forum User
- Location
- Royal Oak, Michigan
High and low pressure tubes are different diameters right? The big one is the low pressure.
wolfpackjeeper
NAXJA Forum User
- Location
- 500' and 500KCAS, RAF lakenheath
actually I think I said that backwards, the low pressure side is the one you want and it is on the block side.
On my MJ the ports were actually on the same side. I had to trace the lines back to figure it out.
On my MJ the ports were actually on the same side. I had to trace the lines back to figure it out.
- Location
- MilkyWay Galaxy
Not on a 90 or older model. I think they switched to R-134a in 92, but not sure. I had a 91 ford that was R-12.
Your 90 was, may still be R-12? If it has the thread fittings it is probably still R-12. R-134a uses push / pull quick connects.
Both are on the compressor block on the older jeeps.
You need to follow the lines. The line from the compressor to the expansion valve (on the firewall ) will be the low pressure return side.
The line to the filter /dryer that leads to the condenser after the filter dryer, is the high pressure side. The High pressure side has a small diameter hose, and the low pressure side has a large diameter hose.
You can't really hook R-134a hoses up backwards at the jeep, as the QC fittings are different sizes, and the other end of the hoses are color coded, if you use a gauge set up.
If you get the R-12 hoses backwards, it will show up at the pressure gauges, but Be sure your gauge set valves are closed when you attach AC hoses. Then check the pressures on the low / high sides to make sure the hoses and connections are right, to avoid blowing yourself and the refrigerant bottle up :fuse: by connecting the refrigerant bottle up to the wrong side. :shiver:
XJNagle,
Sounds like you are switching from R-12 to R-134a with a retrofit kit, right?
IN that case you need to follow the lines like I said above, to find the low pressure side, and then open the old style valve port with a wrench, under the metal cap/cover.
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