A/C Help

hvydrop97

Observer
Got my new to me ZJ here in NC and I'm in the process of building an expo rig again. (last project was cut short due to a pcs) I've done a good bit of searching and all I found was evaporator( but I have no water inside) and a/c compressor clutch (mine works fine) the compressor comes on in 5 to 6 second intervals for about 7 seconds each time. after I let it run for a bit I kill the engine, and there's a hissing leak sound coming from the engine compartment. I feel like an idiot because I cant find anything leaking out of anywhere and I cant pin point where the sound is coming from. I figure it would be the condenser but I can see anything coming from that area. So far I've never had a vehicle with even remotely working air conditioning and it would be a welcomed change for this North Carolina summer. Any insight would be awesome. Thanks
 

taiden

Observer
My XJ makes that noise every time I shut it off. I assumed it was the vacuum canister bleeding back into something. I never looked into it.

Your clutch should stay on 100% of the time that your AC is turned on. Pull the pulley off, and remove a shim behind it. This turned my AC from intermittent AC into 100% awesome cold as ice AC. :)
 

hvydrop97

Observer
well I bypassed the lo pressure switch with a jumper wire which allows the clutch to run constantly but the lines get iced up like crazy, I've heard of guys running it like this for years and not having problems but I've also heard of guys freezing the evaporator. The jumper wire makes it run constantly as well.
 

chasdb

New member
The a/c clutch should not stay engaged all the time when the a/c switch is turned on. The system is designed to shut off the clutch if the pressure is too hi or too low or the evaporator freezes up. This is to save the pump from damage. The noise you hear is the hi and low side if the system equalizing. To find a leak I have had the best luck recovering the remaining freon and charging the system with nitrogen to 50 and 275 psi and spraying the hoses, condensor, recevier drier, tube conections, shrader valves, relief valve, compressor with soapy water and looking for bubbles. I have used sniffers, injected dye in the systen and used a black light. But best of luck personally with nitrogen. I check at high and low pressure because I have had o -rings seep at low pressure but not high as well at hoses at crimps. If you don't see a leak checking items above, pull the clutch and see if it's leaking at thd shaft seal. If no luck it could be the evaporator so you would have to pull the dash and split the box and then you may see pag oil at the location of the leak. Any time you replace the compressor, replace the reciever dryer. If the compressor failed and made metal (rotary group broke) you need to flush the system and replace the oriface or expansion valve. Yes a/c can take a bunch of special tools and is labor intensive. Once you find the leak, you need to evac the system whick pulls to moiture out if the system and charge by weight. Moisture combines with freon and can form an acidic solution and will attack your componets. There is a bunch of good info in the support section at sandendotcom. I don't believe in any of the conditioners or stop leak "snake oils" added to some refrigerants as band aids. Hope this helps.

Charles
 

hvydrop97

Observer
Short, sweet, to the point. Thanks Charles, I don't mind about the labor, its the money that gets me. I've heard some good things about Red Angel A/C leak stop so I'm going to give that a try first. Its a blue devil product and I've had great success with them. If that doesn't work at least I'm only out 30 bucks and then I can go onto getting a hold of all the gauges and specialty tools necessary to work on a/c systems. I figure ill be acquiring them anyway somewhere down the road, might as well be early that later.
 

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