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R4 Compressor Cycling

TNshadetree on Thu July 17, 2008 1:34 PM User is offline

Year: 1985
Make: Chevy
Model: Monte Carlo
Engine Size: 305
Refrigerant Type: R134a

I converted a 85 monte carlo over to R134a. It blows cold when the compressor clutch is kicked in, but it doesn't cycle so much as run continous and then when it does cycle off it stays off for an extended time. I've been too impatient to see how long. Once sweat starts running down my forehead I usually turn the system off for a few seconds and turn it back on so the clutch engages.

This year car has an adjustable low pressure switch located on the dryer. But none of my adjustment attempts seemed to accomplish anything in terms of cycling the compressor. I finally got parinoid that I might have adjusted it where it wouldn't protect the compressor, so I bought a new switch and installed it without adjusting it. Should this compressor be cycling more? I had a shop tell me it should be on about 13 seconds and then cycle off.

Another issue that may be related is when changing the oil I filled the compressor well, maybe 3 ounces. But I was so concerned about getting the new dryer hooked up quickly I forgot to add additional oil to the dryer or inlet hose to the compressor.

brickmason on Thu July 17, 2008 2:41 PM User is offline

Check the compressor clutch air gap. May be too wide.

It would help to post the pressure readings also because the system may be operating normally as it should due to excessive high pressure shutting down the compressor and not allowing it to restart untill the high pressure slowly creeps back down.

Be sure the condenser is getting plenty of air flow too and not clogged with dirt, bugs, debris or have several bent cooling fins which would cause high pressure to exceed too much to allow the compressor to even start once the high pressure heats up.

Just another brick in the wall

Had a little mule I fed him castor oil and every time he jumped the fence he fertilized the soil

2005Equinox on Sat July 19, 2008 1:29 AM User is offline

I have a 1985 Caprice with probably the same system. If it is idling to compressor normally doesnt cycle at least not much. When I am driving along it cycles more depending on temperature and fan speed setting. Had to get the cycling switch replaced because mine would do the same thing. Mine also has an adjustable low ressure which took people quite a long time to discover. Also do what brickmason has told you.

2008 Chevrolet Impala LS
1981 Pontiac Bonneville

2007 Sears Craftsman Lawn Tractor

1985 Chevrolet Caprice

1986 John Deere 165 lawn tractor

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