A/C Compressor Clutch Seal Replacement

[RS23VOA]

Hey guys
Can anyone direct me to a youtube video of a compressor rebuild? My compressor is oily around the clutch and I'd like to replace the seal and get the system going again. I checked The Rock and not much going on in the way of replacement parts. The system still has pressure on it after sitting 32 years.

 

[Davea Lux]

Hey guys
Can anyone direct me to a youtube video of a compressor rebuild? My compressor is oily around the clutch and I'd like to replace the seal and get the system going again. I checked The Rock and not much going on in the way of replacement parts. The system still has pressure on it after sitting 32 years.

View attachment 637365

These seals will leak if the gas pressure drops from normal operating ranges. Gas pressure against the back side of the seal along with a thin film of oil is what creates a gas tight and oil tight seal. You probably still have a good seal if the system has retained pressure. You can remove the clutch assembly without disturbing the seal. You can then clean up the inside of the clutch and the front of the compressor. After doing that, you can bring the charge up to specs and see if you still have leakage. Do you what the system is currently charged with? Your compressor still has factory fittings installed, so it probably still is charged with R-12. If you can find some R-12 to do a recharge, i would suggest going that route. If the system is to be recharged with R-134a, all of the old refrigerant and refrigerant oil will need to be removed before a new charge is installed. A new filter/dryer and all new green o-rings will also need to be installed. Seal kits are still available Mopar part #1426501, Murray park and others sell them in the $35 range.

Dave

 

[Trace 300 Hurst]

Take it from an expert: If you system still has ONE SINGLE PSI in it, don't even think about replacing the compressor seal. You are far ahead of the game. The Rock rebuilt compressors are NOT rebuilt, they're merely cleaned up and painted with gooey black paint. I can't even begin to tell you about the horrors I've found in so-called rebuilt compressors.

So, depending upon the refrigerant you go with you'll want to drain the sump and flush the system and put in 8 oz of the compatible oil. Then I would suggest you put a new clutch assembly on it so you'll have another 50 years of life. Other than that.....don't f**k with it.

Edit 5 minutes later: Dave Lux knows what he's talking about. He taught me!

 

[RS23VOA]

These seals will leak if the gas pressure drops from normal operating ranges. Gas pressure against the back side of the seal along with a thin film of oil is what creates a gas tight and oil tight seal. You probably still have a good seal if the system has retained pressure. You can remove the clutch assembly without disturbing the seal. You can then clean up the inside of the clutch and the front of the compressor. After doing that, you can bring the charge up to specs and see if you still have leakage. Do you what the system is currently charged with? Your compressor still has factory fittings installed, so it probably still is charged with R-12. If you can find some R-12 to do a recharge, i would suggest going that route. If the system is to be recharged with R-134a, all of the old refrigerant and refrigerant oil will need to be removed before a new charge is installed. A new filter/dryer and all new green o-rings will also need to be installed. Seal kits are still available Mopar part #1426501, Murray park and others sell them in the $35 range.

Dave

Thank you Dave. I've owned the car since '91 and it doesn't have the newer fittings so I'm confident it has R12. I'll give this a try and hopefully everything will work out. Thanks again.

 

[RS23VOA]

Take it from an expert: If you system still has ONE SINGLE PSI in it, don't even think about replacing the compressor seal. You are far ahead of the game. The Rock rebuilt compressors are NOT rebuilt, they're merely cleaned up and painted with gooey black paint. I can't even begin to tell you about the horrors I've found in so-called rebuilt compressors.

So, depending upon the refrigerant you go with you'll want to drain the sump and flush the system and put in 8 oz of the compatible oil. Then I would suggest you put a new clutch assembly on it so you'll have another 50 years of life. Other than that.....don't f**k with it.

Edit 5 minutes later: Dave Lux knows what he's talking about. He taught me!

Thanks for the heads up Trace. I'll go Dave's route.

 

[Trace 300 Hurst]

Thanks for the heads up Trace. I'll go Dave's route.

Since others will probably research this thread someday, I'll tell you about my Rocky Horrors. First compressor, no oil pump check ball and spring....meaning that unit would have seized in short order. [Note, some later compressors didn't use the ball/spring and there's no passage for them. But not this particular unit...it needed them for sure.] Second compressor....if you can believe this...had a broken and missing reed valve (of the three-reed assembly) in the low pressure head. But no piston damage!! I've never figured this one out. So....did some rebuilder in Cambodia or wherever put an OBVIOUSLY bad part in that unit? Or more likely, like I said above, it's not really rebuilt at all. Just paint and maybe a front seal.? Maybe. Regardless, in my experience, 100% of the Rocky/Four Seasons units I bought were bad.

So what I learned is that a junkyard unit with a buildup of "greasecrud" on the mounting bracket and no R134 fittings is likely to be Solid Gold, assuming you can rotate the assembly, etc.

Since it seems that you still have R12, it's just a matter of adding the proper mineral oil. Four Seasons 59000 Four Seasons R12 Mineral Oils | Summit Racing To get the level right with the compressor still in place on the engine, you'll need to make yourself a dipstick as shown in the service manual. If the compressor is on the bench you can pour the old oil out (give it an hour or two, moving it around to drain various cavities in there) and fill with a measuring cup.

Dipstick with high and low level markings.

Here's two compressors, one with the oil passage (see the spring) and one without (see the red spot).

 

[RS23VOA]

Since others will probably research this thread someday, I'll tell you about my Rocky Horrors. First compressor, no oil pump check ball and spring....meaning that unit would have seized in short order. [Note, some later compressors didn't use the ball/spring and there's no passage for them. But not this particular unit...it needed them for sure.] Second compressor....if you can believe this...had a broken and missing reed valve (of the three-reed assembly) in the low pressure head. But no piston damage!! I've never figured this one out. So....did some rebuilder in Cambodia or wherever put an OBVIOUSLY bad part in that unit? Or more likely, like I said above, it's not really rebuilt at all. Just paint and maybe a front seal.? Maybe. Regardless, in my experience, 100% of the Rocky/Four Seasons units I bought were bad.

So what I learned is that a junkyard unit with a buildup of "greasecrud" on the mounting bracket and no R134 fittings is likely to be Solid Gold, assuming you can rotate the assembly, etc.

Since it seems that you still have R12, it's just a matter of adding the proper mineral oil. Four Seasons 59000 Four Seasons R12 Mineral Oils | Summit Racing To get the level right with the compressor still in place on the engine, you'll need to make yourself a dipstick as shown in the service manual. If the compressor is on the bench you can pour the old oil out (give it an hour or two, moving it around to drain various cavities in there) and fill with a measuring cup.

View attachment 637457

Dipstick with high and low level markings.
View attachment 637459

View attachment 637464


View attachment 637458


Here's two compressors, one with the oil passage (see the spring) and one without (see the red spot).
View attachment 637460

View attachment 637461

Thanks Trace. Mine is still on the car so I'll start cleaning and find the plug to check the oil. Can you tell me how the clutch assembly comes off? Not sure if it's bad or not. Maybe it doesn't even need replaced. I've been driving the car and it doesn't make any noise but I haven't turned the AC on either.

 

[Trace 300 Hurst]

Yes, you may not need a new clutch at all. They seem to last forever OR the magnetic clutch coil has burned out...and not really any problems in between. I think there's a test for clutch face wear, but I didn't see it in the FSM just now. I would do the oil and R12 first and see if it all works. I'll bet it does. Maybe @Davea Lux can advise on clutch wear, etc.

You're going to need the Factory Service Manual for your car. Easily downloaded from MyMopar.com.

You'll need a spanner tool to hold the hub stationary so you can loosen the hub retainer bolt, which isn't very tight at all (20 foot pounds). No big deal. Spanner tool: https://www.amazon.com/Adjustable-F...lpcontext&ref_=fplfs&smid=A2MBJW8WVQQ3CX&th=1 The spanner goes in two of the three holes in the front of the clutch assembly so you can keep that from turning while you loosen the bolt. You can't hold that front plate from rotating with your bare hands.

Then you thread a 5/8-11 x 2 or 2.5 inch long cap screw (which you probably don't have in your household screw jar, but easily found at good hardware stores or supply company or online) into the hub and give it just a little twist (no need for the spanner in this step) and the clutch will pop off right away. By right away, I mean it comes loose and if you're not ready for it, that heavy friggin' thing WILL pop off and destroy your radiator on the way down.

Now that you have the rotating assembly off, there are three hard to see hex screws that hold the stationary clutch field (electromagnet) assembly to the compressor. No need to remove the shaft key, btw.

Install new magnet, wire pointing up, and note that the three screws only get 17 INCH pounds, so we're talking screwdriver tight...very easy to wring them off, so be careful. Then you install rotating assembly on the shaft--making note of the crank key and the corresponding slot in the clutch assembly--and tighten the hub retainer bolt to 20 foot-pounds, using that spanner tool again. That will totally lock the assembly onto the tapered shaft. You're done with the scary stuff.

FYI--I'm off to Mecum Kissimmee tomorrow morning to look at very expensive Hemi cars, so I won't be checking the forum until Monday.

 

[RS23VOA]

Yes, you may not need a new clutch at all. They seem to last forever OR the magnetic clutch coil has burned out...and not really any problems in between. I think there's a test for clutch face wear, but I didn't see it in the FSM just now. I would do the oil and R12 first and see if it all works. I'll bet it does. Maybe @Davea Lux can advise on clutch wear, etc.

You're going to need the Factory Service Manual for your car. Easily downloaded from MyMopar.com.

You'll need a spanner tool to hold the hub stationary so you can loosen the hub retainer bolt, which isn't very tight at all (20 foot pounds). No big deal. Spanner tool: https://www.amazon.com/Adjustable-F...lpcontext&ref_=fplfs&smid=A2MBJW8WVQQ3CX&th=1 The spanner goes in two of the three holes in the front of the clutch assembly so you can keep that from turning while you loosen the bolt. You can't hold that front plate from rotating with your bare hands.

Then you thread a 5/8-11 x 2 or 2.5 inch long cap screw (which you probably don't have in your household screw jar, but easily found at good hardware stores or supply company or online) into the hub and give it just a little twist (no need for the spanner in this step) and the clutch will pop off right away. By right away, I mean it comes loose and if you're not ready for it, that heavy friggin' thing WILL pop off and destroy your radiator on the way down.

Now that you have the rotating assembly off, there are three hard to see hex screws that hold the stationary clutch field (electromagnet) assembly to the compressor. No need to remove the shaft key, btw.

Install new magnet, wire pointing up, and note that the three screws only get 17 INCH pounds, so we're talking screwdriver tight...very easy to wring them off, so be careful. Then you install rotating assembly on the shaft--making note of the crank key and the corresponding slot in the clutch assembly--and tighten the hub retainer bolt to 20 foot-pounds, using that spanner tool again. That will totally lock the assembly onto the tapered shaft. You're done with the scary stuff.

FYI--I'm off to Mecum Kissimmee tomorrow morning to look at very expensive Hemi cars, so I won't be checking the forum until Monday.

View attachment 637466

View attachment 637470

Okay thanks for all the good info and good luck buying the very expensive Hemi car!

 

[mrfury68]

Those compressor clutches are pretty robust and last a long time. As long as it engages, doesn't slip or chatter while running, you should be fine. Like the previous posts stated, hang on to your compressor as long as you can. A factory service manual is a must have tool for our old rides.

 

[Trace 300 Hurst]

And you can check so see if the clutch engages by jumper-ing the connection on the low-pressure cutout switch mounted on the receiver-dryer (this is necessary if there is little or no pressure in the system, but might was well do it anyway, regardless of charge). Then turn on the ignition key (engine off) and then turn on the AC. You should be able to hear (or see, with a helper) the clutch engage.

 

[RS23VOA]

And you can check so see if the clutch engages by jumper-ing the connection on the low-pressure cutout switch mounted on the receiver-dryer (this is necessary if there is little or no pressure in the system, but might was well do it anyway, regardless of charge). Then turn on the ignition key (engine off) and then turn on the AC. You should be able to hear (or see, with a helper) the clutch engage.

Thank you.

 

[volksworld]

as per your original request go to MyMopar...go to master tech videos...browse by model year...go to 1975...and click on the video "the air conditioning compressor"...that will show how to rebuild it...and if you decide to replace the seal Auto Zone has a Santech seal MT 2034...many of the NOS seals out there have surface rust from how old they are and how they were packaged and they will leak...but I completely agree with what Davea Lux suggested

 

[RS23VOA]

as per your original request go to MyMopar...go to master tech videos...browse by model year...go to 1975...and click on the video "the air conditioning compressor"...that will show how to rebuild it...and if you decide to replace the seal Auto Zone has a Santech seal MT 2034...many of the NOS seals out there have surface rust from how old they are and how they were packaged and they will leak...but I completely agree with what Davea Lux suggested

Thank you!

 

[Trace 300 Hurst]

Good NOS cans of R12 used to be readily available on eBay, but they stopped that 2-3 years ago. Last R12 I bought a year ago was on Mercari: Your Marketplace , which is a junior eBay.


Just checked...Mercari has LOTS of R12. Bring your wallet.

 

[RS23VOA]

Good NOS cans of R12 used to be readily available on eBay, but they stopped that 2-3 years ago. Last R12 I bought a year ago was on Mercari: Your Marketplace , which is a junior eBay.


Just checked...Mercari has LOTS of R12. Bring your wallet.

View attachment 637500

Thanks. I have 4-5 cans if i can find it!

 

[ImperialLeBaron1969]

Interesting tread! I have some gas, R12 I assume, in my RV2 compressor. I dont think its that much gas because if I energize the clutch, the compressor deponent cool.
One thing worries me. The compressor is much easier to turn by hand than a GM A6 with the right amount of gas. Could it be that the compressor piston rings dont seal and build up a good gas pressure?

 

[noah300g]

I've been

Hey guys
Can anyone direct me to a youtube video of a compressor rebuild? My compressor is oily around the clutch and I'd like to replace the seal and get the system going again. I checked The Rock and not much going on in the way of replacement parts. The system still has pressure on it after sitting 32 years.

View attachment 637365

very disappointed in the compressors I've gotten from Rock Auto. Not sure there are any 'new' RV2 compressors anywhere anymore. Next time mine fails I'm going to a Sanden.

 

[Clover]

as per your original request go to MyMopar...go to master tech videos...browse by model year...go to 1975...and click on the video "the air conditioning compressor"...that will show how to rebuild it...and if you decide to replace the seal Auto Zone has a Santech seal MT 2034...many of the NOS seals out there have surface rust from how old they are and how they were packaged and they will leak...but I completely agree with what Davea Lux suggested

I used an NOS seal and it did have surface rust from the packaging but it was not on the sealing surface, which was not rusty. It sealed just fine.

 

[Prusakowski]

Compressor rebuild video