take belt and turn it it should turn about a 1/4 inch in other words grooves in belt facing down turn belt so grooves face you after that it should be hard to turn more, do this at longest strech of belt between accessories

 

ok cool, thanks for taking the time to explain.

EDIT: The belt passed the 1/4 turn test.

 

So many people confusing this thread. Some with their troubles, some with just bad advice!

Air in the system will not ruin anything. It compresses and expands, just not as much as freon. Look at shop air compressors, let it blow out - it's cold when it expands! Symptoms of air in the system is it just doesn't get as cold as it should be. Rule is 40 or below is fine.

Water will turn to ice, ice plugs it up. Symptom is it gets cold it's fine for awhile, then stops getting cold. Let it sit for awhile - ice melts, cold again.

Evacuating the system removes the air and water. Usually not needed unless you had the system open.

The low pressure connector can be any color, black, grey etc, depending on the year. It's the one that's connected to the low pressure switch - on or near the dryer - there's only one!

Bypassing that connector during the time you are diagnosing and repairing is fine - even if it's hours! Just don't leave it on while driving.

The compressor "sucks" the freon out of the low side, compresses it, then it goes to the condenser to get cooled, then on to the expansion valve - there it expands and get very cold. From there it goes inside to cool the evaporator, then through the drier, then back to the compressor.

It's not rocket science, but some would have you believe it is.

We probably did at least 1000 AC repairs/recharges at the 4 shops I owned. And that was not our specialty, it was an easy side job! Our specialty was high performance and dyno tuning.)

When filling it static - engine off - the can has about 15-20 lbs in it. Freon will flow from the highest pressure to the lowest. Adding just one can static rarely will turn on the compressor when started.
YOU HAVE TO BYPASS THE LOW PRESSURE SWITCH and run the engine to get the compressor to suck the rest of the freon out of the can. That's rarely enough. a 2nd 12oz can usually is - at least enough to run with the switch re-connected.

Once it runs with the LO switch connected, do what I outlined in a previous post on this thread to get the max freon in it.

Buy an AC book if you don't believe me, or take it to a shop.

Whenever we got a customer that was full of internet rumors and wild bull---- theories - we asked them to leave and would not work on their car.

Other shops hated us - because we did not make up stories and replace unneeded parts. We just fixed them without bleeding them to death.

 

Nicely written! What is your thoughts on the oil in the system? And about how long does it take to empty a small 12oz can? Also, why is my compressor kicking off when I have the low pressure side bypassed? Could it need a shim removed or is there another reason? Again thanks for the info.

 

A 12oz can running, will take 2-3 minutes.

If it's cycling with the lo pressure switch bypassed - if it's really the right connector, use a gauge to check the Hi side - you may have a restriction - it'll be way too high. Should be around 250 lbs with the lo side 35-45 - depending on the ambient temp.

Too much juice will make them both too higher, a restriction will just make the hi side too hi..

 

Ok, the saga continues. After letting my jeep sit at work for a few days I brought it home and the pressures on the high and low side were the same as when I left alone, so if I have a leak it's a slow one. I jumped the compressor and added another can of freon. This brought the pressures to 20 and about 175, and it was blowing cold! Here's the kicker though. To get the compressor clutch to kick in I have to take a flathead screw driver and place it between the front plate and the othe plate that doesn't move and twist the screw driver as to spread it apart. If I do that it works for a bit then when it cycles it stops spinning even though the electric fan kicks on. So once again I put the screw driver omit and it works. There are two wires running into the clutch, but the are sealed. Do i need to check the voltage on either one of those? If so how, they are sealed. And if I find a place to check them what should the voltages be. Again it's a 99 xj with a 4.0l and it has a Sanden compressor with a 709T stamped on it.

 

Also, when the compressor clutch isn't kicking in the pressure on the low side will go up and to 45 or so and the high side goes down to about 40 or so

 

Okay, a couple of things...

When your system isn't running (compressor clutch not engaged), you'll have a near/full equalization of pressures between the high and low sides. That's normal, and reflected in pressures you described.

The systems on these vehicles have a low-pressure shut-off switch that kicks in around 38 pounds. Since you start at 40 on the low side, the system shows adequate pressure and allows the clutch to cycle on. However, once the compressor is running it will suck freon (and the air I'm sure you have) from the low side to the high side. This increases high side pressures, but lowers low side pressures to the point that your low pressure cut-off switch kills the clutch. Once the system is no longer running and you have a bit of equalization, the low side pressure increases and the clutch kicks in again. Then you start the whole process over again.

It's because you simply do not have enough freon in your system. And, if you cant get any more to go in, there's a good chance it's because you have air in there (which will compress at different rates than freon) and it won't allow room for any more freon. The compressor and relative volumes of the high and low side were carefully chosen to work within the compressive ratios of r134a. Nothing else. It's a balancing act.

Not to put too fine a point on it, but now that you have evidence that you are no longer leaking, you need to get the system vacuumed down and recharged properly. I've explained it several times. Even if you were getting pressures in the normal range, the system will simply not cool as well when it is compressing a freon/air/moisture mixture as it will when compressing just freon. If air worked as well, there's be no need for freon. Also, because air (a mixture of nitrogen, oxygen, CO2, other gases, and water vapor) compresses at different ratios than freon, you can cause out-of-range pressure differentials between the low and high sides at any given point. This may cause excessive high side pressures and premature wear on the compressor.

If you want to keep pulling your hair out and wasting your time, that's your prerogative. But seriously, spend the $60 bucks to have a shop vacuum and charge it and be done with this. Or, rent a vacuum pump and suck it down yourself, but this will have to be done by someone if you ever want it to work the way it's supposed to.

Just trying to save you a lot of time and frustration. This is no different than having an engine not run because there is water in the tank, and thinking you can fix it by pouring more gas in on top of the water. It's just not gonna work. And dang, it's starting to get hotter out there so you need this fixed soon!

 

If the engine revs and the electric fan kicks on, shouldn't the compressor clutch kick in as well. Or is it possible the clutch doesn't work in conjunction with the fan and motor reving?

 

there equalizing its normal

 

""""If the engine revs and the electric fan kicks on, shouldn't the compressor clutch kick in as well. Or is it possible the clutch doesn't work in conjunction with the fan and motor reving? """"""

no, the fan and engine speed are commanded by the AC DASH switch. The clutch is commanded by the pressure switch and relay.

Funny - someone thinks 45 lbs of freon is different than 45 lbs of air.
It will get cool with air only, just not near as cool as with freon.
I've already explained what water will do.

Some people that might have recharged one or two before become an expert.

r-12 was designed to have a much greater coefficient of expansion than air without being flammable like propane. R-134 has an even greater expansion rate, that's why you use about 1/3 less VOLUME.

But 45 lbs pressure is 45 lbs pressure even with carrot juice.

Remember, the pressure readings are ABOVE ambient.

Check the voltage right at the clutch connector - see if the voltage goes away or it's still there but the clutch doesn't engage. it could be a defective coil in the clutch - they do get intermittent.

to remove air you can purge it - put r-134 or AC Flush in the low side with the high side open. when you get some gas out from the hi side, it's flushed out the air. it's illegal, so don't release much, but it works.

 

Update. Put some more freon in the thing. I'm showing 31 and 150+ on the gauges but I was still having some slight issues with the compressor staying engaged, although it would engage with a little help. So I took the pressure plate off of the front, which was very ez. Took the bolt out and just pryed a little with two screwdrivers. I found 1little shim, so I took it out. Filed the rust off of the plate, crossed my fingers and reinstalled the plate. Shazam! It's working pretty good now. If it continues leaking I am just gonna have to weigh my options with a new compressor or just charging it occasionally. As%#holezone has freon for 14.99, but I found that OddLots has it for 8.00 per 12oz ! Thanks to all for the help, advice, and guidance.

 

I'm having the same problem. How did you get pressure plate off without it spinning? Did you put something in there to hold it still while you loosened the bolt?

 

I used a big flathead screwdriver and put it against one of those round tabs with the rubber and a spot just in front of the battery. With the screwdriver wedged in there, i used a breaker bar with a 14mm socket. The bolt really isn't on with very much torque at all. After that I just pryed the plate with screwdrivers on both sides till I came out a little bit, then wiggled it with my hands the rest of the way. My compressor is a sanded 709. I found a you tube clip that shows the plate being pryed off like that. I don't think I can get the link to the video on here. But I searched sanden compressor clutch, I think. It was a sanden company video.