Noisy AC compressor repair (pulley bearing)


Screech/howl coming from AC compressor as shown in this video: AC compressor noise


The compressor's pulley bearing is worn out, causing the noise as shown here:
Pulley and clutch free spin
and here:
Pulley bearing spin, off vehicle
NOTE: It is also possible that your clutch disc could be dragging due to improper gap or a broken spring. This can be confirmed by spinning the clutch disc by hand while the pulley remains stationary (as shown in the "..clutch free spin" video above). in my case the clutch disc was fine.... but you should confirm this on your compressor. If your clutch disc is broken you can buy a new one from the AC Compressor Rebuilding Facility referenced at the end of this write-up.

A repair shop will tell you the entire compressor needs to be replaced, which also necessitates a full evacuation & recharge of the entire AC system and replacement of the drier/filter. Nissan dealers will charge >$900 for this job.. Independent shops may do it for $500-$600.

A better solution is to simply replace the pulley bearing for $30. The compressor itself remains on the vehicle so there is no need to recharge the system and replace the drier, and you save the cost of a new compressor (>$300).

NOTE: Bearing replacement is only effective if the system is otherwise in good working condition (compressor has not seized, system has not leaked excessive oil, etc). If the compressor internals have been compromised then the entire compressor should be replaced.

NOTE: Bearing Repair vs. New Compressor
Many people seem to think it is better to just put on new compressor. I would advise against this unless the compressor is damaged internally. Aside from the extra $400+ for a new compressor, drier/filter & required recharge, there is considerable risk that the recharge may not be done correctly - infant mortality of replacement AC compressors is very high due to improper charging procedures (incorrect amount of oil, wrong oil type, failure to completely recover all old oil & refrigerant, failure to flush debris from the system, etc, etc). It is NOT a DIY job, and even shops often screw it up; too risky and too expensive when all that's needed is a new bearing.

Replacing the bearing will take 1-2 hours for a novice, barring any unforeseen problems. I could do it again in 30 minutes but if you don't want to try it, just buy the bearing and take it to a local mechanic. negotiate a reasonable fee -- 1hr labor or $75. Any competent mechanic with a press can do the whole job for that, you'll still save a lot of $$ and not have to worry about the recharge.

Repair Procedure: - This should take 1-2 hours if all goes well
i) Tools needed:
- AC clutch removal tool (free rental from Autozone)
- snap ring pliers (free rental, or $6 to buy)
- 10mm & 14mm sockets
- 12mm wrench
- hammer & round blunt for bearing extraction
- 10 ton press for bearing insertion (or pay a shop $15 to do it)

ii) Parts needed:
- AC Clutch bearing (<$20 from Houston bearing online)
NOTE: There are at least 4 different compressors on the 4th gen(1995-99), and you need to verify the compressor model and/or bearing size before you order the bearing. of these will work....*6017@@

EDIT---> The bearing for the '99 Calsonic v618 is a standard ball bearing 62mm x 40mm x 24mm (ODxIDxW). It can be purchased from any bearing supply company for <$20 just find one and tell them what you need. Here's one that should work...

- 36"~37" belt (if you wish to bypass compressor while completing the job). EDIT - measure the bypass belt path for your car with string... it seems some 4th gens are set up differently, or some people have UDP pulleys.

iii) Compressor Bypass - you my want to bypass the compressor if you need to drive the car while performing the job (e.g. if you need to take the pulley to a shop to press the new bearing in). Simply buy an appropriate 6-groove belt (NAPA is a good source) and run it around the alternator and you're good to go. Measure the bypass belt path with string to determine your belt size.

iv) Repair Steps
1) Raise vehicle on ramps & remove plastic shroud underneath AC compressor.
2) Loosen idler pulley nut, relieve tension on belt and remove belt.
3) Confirm noisy bearing by spinning pulley as show in video above.
4) The AC clutch and pulley assemblies are as follows:

5) Remove clutch center bolt using the clutch tool as follows

6) Remove clutch assembly by pulling outward with hand pressure - be careful to keep the shim. If clutch disc does not come off with hand pressure, a puller will be required. This may require detaching the compressor body from the engine block (while keeping refrigerant lines connected) and positioning it so as to make room for the puller.

7) Remove pulley snap ring.

8) Remove pulley with hand pressure. Again, a puller may be required.
9) Extract bearing using a hammer, a suitable round iron "blunt", and 2 boards for elevation. This will require a tremendous amount of force. The bearing is held in with "peens" -- little indentations in the pulley housing. you will need to force the bearing past those peens....

10) Press in new bearing: If you have access to a 10T hydraulic press you can do this in less than 5 minutes be sure to use a suitable "pusher race" so as not to damage the new bearing. Alternately, take the pulley and bearing to a trusted mechanic and negotiate a reasonable fee. For 10 minutes of work it shouldn't cost more than $15.

here's the new bearing pressed into the pulley (note the remnants of the "peens")...

NOTE: I would not use a hammer to force the new bearing in - I believe that would damage it. The force of extraction caused my old bearing to seize.

11) Re-install the pulley and clutch onto the compressor in the same way they were removed.

12) Measure clutch gap to confirm it is within FSM specs.

13) Tighten clutch center bolt, re-install AC belt and tighten to specs.

14) Start engine and test for proper AC clutch engagement.

Alternate Approach: AC Compressor Re-builder...

If you don't want to deal with the hassle of extracting the bearing and pressing it in, you can buy a rebuilt pulley and clutch assembly from an AC re-builder in Florida for $80+shipping w/ exchange. their website is