| My '90 Z has been sitting out this heat, as I've been out of State.. When I came back into the State, I took the Z for a Run, and then let it sit in the Driveway running, while I was waiting to go elsewhere.. after about 10 Minutes in 105 Deg heat.. ac running a BIG POOF and lots of Oil Smoke and noise.. I dashed out to the Car, and shut it off.. Still hissing and gassing.. I knew right away that I'd blown an AC System Component.. Somewhere.. I put it in the Shade.. And on the Jack Ramps to check out later.. Ends up it was the Pressure Relief Valve on the Discharge of the Compressor.. That Blows at something in the 500 PSI range!.. I asked myself why the High Pressure Cut Out Switch did not turn off the Compressor First!.. so I hit the Books.. It looks like the 300's that were R-12, do not have a High Pressure Cut off Switch.. However the Native 134a unit have a Combo Switch installed in the Receiver Dryer rather than the 'Low Pressure Switch' that is on the R-12 units.. I got the Relief valve put back together and sealing, and was able to pull a Vacuum back on the System.. Looking on Line I found a Murray Switch 25829 that is available by O'Reillys Auto for $34.. Low Pressure Cut out/In is 29/30 PSI and the High Cut Out is 391/304 PSI.. I'll install it when it arrives tomorrow, and check the Pressures to see if the performance is ok.. They also have a Murray 36574 that is a 464/377 PSI on the high side, and 29/30 on the low side.. I'll toss that one in if I'm cutting out too soon.. I've never run a Gauge set on the High Side of a driving Auto in 105 Deg heat before.. Then the next thing to check is why did the Temp/Pressure get too hot in the Driveway?.. I've got Twinn Fans on the Radiator, and they were working.. So?.. Book says the Dryer Might be Plugged.. I'll be changing that out anyway.. Cj
|
16:48:08 07/23/24
