I didn't think I needed to until El_Guapo suggested it. I'll check it but for now it functions and that's all that matters.

 

Because if there isn't enough air gap it will destroy the friction faces of the clutch plate and pulley in short order. It will also generate enough heat to wipe out the pulley bearing in a similarly short span. You can even get a really obnoxious situation where the pulley gets enough thermal growth that you get adhesion and the friction surfaces literally microweld and the compressor can't cycle off.

The Sanden manual calls for an air gap of .016"-.031" on installation of a new plate and pulley. Accounting for wear and polishing of the mating surfaces I use .015" for a baseline on used friction surfaces.

On the current Jeep I made the mistake of buying an aftermarket clutch kit when the pulley got noisy and had to adjust until I was down to one lonely .005" shim. I put a Mopar/Sanden clutch kit in it and I still have .035" of shims to tinker with. The Sanden shim kit comes with various thicknesses to get it dialed in perfect and make it go another 15 years before having to look at it again. The aftermarket waste of money only came with a whole whopping one .020" shim and 2 .005" shims.

 

Looks like you're playing the shim shame game with the OP. If the OP's compressor works, so be it.


If his clutch shells out down the road he can change it. BFD.

 

Again, just trying to save him money down the road.

A free 5 minute check with a feeler gauge and a $2 shim (if even necessary) are a whole hell of a lot better than a tow bill if/when that pulley bearing locks up or even a $125 clutch kit.

Don't get me wrong, I love the "it works" attitude - it makes me a lot of money. A few hundred bucks in callout pay because someone didn't want to do a 10 minute verification makes my night.

 

ok, i finally fix my a/c, the problem was the compressor.

it was very close to burn out and it was placing a lot of debri into the system, the expansion valve come out very clogged.

so, i purchase a universal valve holder, clean the entire system with tinner, purchase a new compressor and the problem is gone now.

the expansion valve color is purple.

attached some pictures of the actual work and the parts involved...



this line holds the expansion valve, in order to take it out you need to cut the line





that is were the line that holds the expansion valve is connected.





this is part of the valve, it came out broken





here im cleaning the system, putting some tinner inside the evaporator and take it out with air.

 

this is the universal valve holder i place with the new purple valve





this is the tool i used to cut the aluminum line to take the clogged valve out

 

OK, I jumpered the low pressure switch and was able to get the compressor to kick in and pull in new refrigerant. It was blowing ice cold. I watched the gauge as I filled it and it seemed to be great. I shut it down plugged in the low pressure switch and nothing again. Hot air blowing out. So I tried jumper again still no clutch engagement. Checked the pressure on the gauge and it was way high. Let some out of the system to get it back down to a safe level and now the clutch cycles on and off for 5-10 seconds at a time. What should I try next? Low pressure switch replacement? Or High pressure switch? and I can find the low switch at local parts stores but not the high pressure switch, anyone have a part number for it?

Thanks

 

The High Pressure switch is OEM part number 5015792AA.


Below is a description of your AC functions and a schematic of the switch functions.


I suggest that you take your Jeep to an auto AC shop and have it serviced properly.

 

That was the next step. I guess I will setup an appointment. Just thought I would try simple things before I threw parts at it. Was going to try the shim removal, but the retaining nut won't break loose. Thanks for the help!

 

if your "jumper" doesn't work it sounds like you may have a blockage or excess pressure build up not allowing Freon to circulate. i imagine you did all this sitting still your fan clutch might not be engaging enough to pull cool air across your condenser. No air+hot high pressure Freon=super hot high pressure blockage. what were your pressures?

 

Cool pics.


Thanks for sharing.

 

CAUTION!!! The clutch shim removal will work, however depending on the amount of wear on the clutch/pulley surface, you run the risk of bearing failure and/or melting the activation coil due to friction/heat.

The electric fan will not engage unless activated by the ac signal or temp sensor. It does not automatically engage when the ac is turned on (2000-01 Cherokee 4L).

If the clutch is not engaging, you cannot get a proper ac pressure reading. Usually the pressure is low due to slow leaks (these vehicles are almost 20 yrs old). Add a half can or can of refrigerant until the clutch engages.

A new clutch/pulley/coil will engage properly. If you can find them, they cost as much, or more ($150) as a new compressor. Purchase the appropriate compressor (Sanden 709 or 7H15) for about $120, pop the parts off it and install on your unit. Be sure to check the numbers on your unit housing (709/ 709T, or 7H15), as the 709 has a splined shaft and the 7H15 is smooth with a key on the compressor shaft. The clutch is held on with a 14mm nut (use spanner or ac clutch tool to hold in place). It's also a good idea to mark nut/stud with marker or white out for proper torque reference when reinstalling. Pop it off and use the removal tool or gently pry around the circumference with a screwdriver until it is free. Remove serpentine belt. The ac pulley is secured with a snap ring and press fit on the shaft, remove it using snap ring pliers and a puller (remove the 4 bolts securing the compressor to the bracket tilt it for more access, the ac hoses are flexible allowing for movement). Remove the snap ring securing the coil, and remove the small clamp securing the coil wires. It should slide off the shaft. Install new coil and snap ring. Install new pulley by placing a socket outside the bearing race on the pulley and gently tap home, install snap ring. Install new clutch on splines or shaft key. Make sure ac shaft threads are not marred. If they are run a die over them. Tighten to appropriate mark. Reinstall belt *Add refrigerant each year. The above process takes about an hour with the appropriate tools and parts.

Installing a new unit requires quit a bit of work. You'll need to evac/pressure test the system and purchase a new accumulator/drier, O-rings, and a new condenser while your at it.

 

Alright!!! Another great suggestion for an easy fix. Removed 1 of the 2 shims and it started engaging immediately. Thanks to all who contributed to this thread!

 

Well dang, I was about to do the shim trick on my 1996 XJ before I got through the whole thread. However, my A/C clutch let the smoke out a long time ago, smelled like a clutch burnout, dragged the belt too. Now it spins free and, haven't checked, but I will guess the fuse or relay is dead too. For the longest time the sight window showed green, now it is foggy.

So, back to the plan of replacing clutch/compressor, condenser, and accumulator. lines look fine, but might replace them too.

In another thread, someone said after flushing, to blow the legacy parts out with nitrogen rather than compressed air. Is nitrogen vs clean, filtered, dry compressed air really a thing for this repair?