Bypassing the A/C compressor

[dakota99]

Well my air conditioner compressor in my truck is starting to go south. When it's running i can hear a grinding sound, i believe it is the bearing inside the compressor. It still works, i can cycle it on and off, but the noise stays consistent. I'm afraid of getting out somewhere and having it completely lock up on me, so i ordered another belt, smaller so i can just bypass it for now.

My concern is with the seals in the system. I've read that if you don't use the a/c, the seals will get ruined from lack of oil. Is this true? If it applies to the seals in the compressor itself i don't really care, a new one will take its place probably next summer. I just don't want the seals in other places of the system to go bad. I'll admit i don't know much about the whole thing itself. I know there's a condenser, drier, and compressor, all of which im assuming have seals in them. I'd hate to have to replace everything.

 

[JHZR2]

Id hate that too. Running a good bit at least once every three months is the typical advice of MB, and it has proven valid on systems that are tight after 30 yrs.

 

[Chris142]

Ya when they sit unused they lose the refrigerant.

 

[LeakySeals]

You sure its not the clutch? fairly common failure.

 

[dakota99]

It could be the clutch, honestly i'm not too sure right now. I just know it has something to do with the compressor. When i try to turn the pulley it has some tension and makes a grinding noise.

I've read that you can replace the clutch / bearing assembly, and i just looked in my service manual but it looks very involved. Some parts require tools i don't even have. If i had a good idea of the process i might attempt it. I'd just order a new compressor and have it done now but money is tight.

 

[LeakySeals]

Its not that bad to replace the clutch bearings, replacing the compressor is far more complicated. Verify its that, engage the ac a few times, listen for a change in sound

 

[dakota99]

When the a/c is engaged while driving, the noise goes away after about five seconds, only to come back later. I found a seller online who sells a clutch kit and after reading the process over several times i think i can do it. One of the parts stores should have the tools to loan out.

I'll just use the shorter belt until i get the kit, and until it warms up some. I hear a cold snap is coming.

 

[Kestas]

What you describe does sound like a bad clutch. If you can replace just the clutch you'll save yourself the trouble of evacuating and recharging the system.

I'm sorry to see that Chrysler Corp went away from using a separate belt for the a/c. I thought the separate belt was a good idea... in case the a/c clutch or compressor seized or you wanted to disconnect the a/c.

 

[spackard]

A few months shouldn't hurt.
There's a fog of oil that moves around, starting from the evaporator where the refrigerant boils. It coats everything. The stuff hangs around.

 

[dakota99]

Yeah i was going to run down to the parts store and get a belt for the truck w/o air conditioning, but it wont work. The belt routing diagram under the hood shows a method to bypass the a/c, but the trucks that came from the factory without air conditioning have a different setup i guess. The non a/c belt listed everywhere is 88 inches effective length, and that's about two inches too short. Everyone i talked to that had this problem used a 90 inch belt, which enables you to use the bypass route.

I'm guessing chrysler never intended for someone to actually bypass the compressor on a truck that came with factory air conditioning.

 

[dakota99]

Well i just figured i would update this thread, i did actually get it fixed yesterday. I took advantage of the 66 degrees it was perfect. I got a new pulley w/ bearing, clutch and front hub. The process is actually quite simple, in order.

1. remove the front nut
2. remove the hub
3. remove pulley snap ring
4. pull the pulley off
5. remove coil snap ring
6. remove coil

The install is basically reverse, torquing the hub nut to 10.5 ft lbs. Clutch break in calls for 20 on/off cycles between 1500 and 2000 rpm, which i did on the highway. The only tools i had to purchase were the snap ring pliers and an a/c pulley puller set. I got the OTC set #4536 for $62 on amazon. It's a very nice puller that is quality made. Parts on ebay were $100 for a new electromagnetic clutch, pulley w/ bearing and front hub. New spacer washers were included as well.

The hardest part is getting the pulley back on the compressor. It's a tight fit and most people do it with a press but that's impossible with it installed in the vehicle. I just tapped it lightly with a hammer until it set.

 

[mechtech2]

Who cares if the seals go bad?
The unit is already puked.
Fixing it will require new seals anyway.