Compressor seal leak

[joshwilson3]

Looks like the front seal on my compressor is leaking. After I removed the frisbee and put on a new belt, I later started seeing a small amount of black spray on the tensioner, upper control arm, and under side of the hood. It is an 89, so it has the Nippondenso 10PA20C.

Though I have heard of some who's compressor has leaked there for 10+ years with no problems.

Though, I was wondering if anyone here has replaced that seal? I think you can get a new front seal kit from Autozone for $25. I did come across a couple of sites that had some good info.

Nippondenso 10PA20C Compressor Rebuild pics - Rennlist Discussion Forums

www.pelicanparts.com/techarticles/911_Nippondenso_rebuild/911_Nippondenso_rebuild.htm

[boomdriver]

personally, I don't think it's worth replacing a seal. If you have to pull the compressor, a new seal leaves you with an old compressor with a new seal. There are still many worn parts that will fail rendering your work pointless.
If a seal fails after this many years its because the shaft bearing is also failing or there is metal contaminating the system that has chewed away the seal. Next will be the shaft trying to wobble or work its way outward and screwing with belt alignment.

Rebuilt compressors can be had for $200 and the peace of mind that brings is worth lots more.

[joshwilson3]

personally, I don't think it's worth replacing a seal. If you have to pull the compressor, a new seal leaves you with an old compressor with a new seal. There are still many worn parts that will fail rendering your work pointless.
If a seal fails after this many years its because the shaft bearing is also failing or there is metal contaminating the system that has chewed away the seal. Next will be the shaft trying to wobble or work its way outward and screwing with belt alignment.

Rebuilt compressors can be had for $200 and the peace of mind that brings is worth lots more.

I've been told a front seal leak on these Nippondenso compressors is common. I've been told a leaking front seal causes the shaft to go bad in time. Never heard the shaft causing the seal to go bad. I've also heard some guys saying theirs have been leaking for 5-10 years and 100,000 miles and it still holds a charge.

Where are you finding compressors for $200? All I've ever seen are over $400 for rebuilt. And over $600 for new.

Do you have a link of where you got your rebuilt compressor from?

Though, I have read alot to avoid rebuilt compressors. Though, I think I would try just replacing the seal before I'd spend $600+ on a new compressor.

[boomdriver]

I found at rebuilt compressors with warranty at all the local parts stores similar in price. I bought one from O'Reillys for just over $200. Auto-zone had rebuilt for $189 and new for close to $300. Since this compressor is NOT a vette only part and is common on many different makes and models, I was not concerned with a specific type or spec. I have the more common make, not the nipon.
Almost ALL compressors end up at one of two places to be rebuilt, so where you buy is just a matter of their mark-up for the sale price.

I do not understand the ability to "leak" for 10 yrs and still hold a charge...High pressure gas seals do not fail for no reason. Something causes them to leak. They are designed to get tighter with the internal gas pressure.
My reasoning is simple, I won;t re-install used parts that are known to have a defect. Thats just asking to do it again. The last compressor that I had was a rebuilt that was installed well over 12 yrs ago and survived the Arizona desert for many years. The factory unit failed in less than 10 years. I am on my 3rd compressor in 1/4mil miles. 5th alternator.
Good Luck with it, whatever your decision.

[joshwilson3]

I found at rebuilt compressors with warranty at all the local parts stores similar in price. I bought one from O'Reillys for just over $200. Auto-zone had rebuilt for $189 and new for close to $300. Since this compressor is NOT a vette only part and is common on many different makes and models, I was not concerned with a specific type or spec. I have the more common make, not the nipon.
Almost ALL compressors end up at one of two places to be rebuilt, so where you buy is just a matter of their mark-up for the sale price.

I do not understand the ability to "leak" for 10 yrs and still hold a charge...High pressure gas seals do not fail for no reason. Something causes them to leak. They are designed to get tighter with the internal gas pressure.
My reasoning is simple, I won;t re-install used parts that are known to have a defect. Thats just asking to do it again. The last compressor that I had was a rebuilt that was installed well over 12 yrs ago and survived the Arizona desert for many years. The factory unit failed in less than 10 years. I am on my 3rd compressor in 1/4mil miles. 5th alternator.
Good Luck with it, whatever your decision.

Your compressor is different and cheaper than 88+. For the 88+, you are looking at over $400 for a rebuilt. And most say not to get rebuilt compressors, but new. So that is over $600. At the dealer you would be looking at close to $1k for a new compressor. I figured $50 was worth a try. I could at least vacuum it out, and pull the orifice to see if there is metal in there.

Though, I have read of a few guys going through 3-4 compressors very fast. Which I guess that is why they say to avoid rebuilt compressors.

Do you know of any way to check out the clutch? I had noticed a rattle come and go that I couldn't find via my scope. I know the clutch can rattle, so I figured I might need to check it out. I think I will at least pull it off to see if I notice the bearing is bad.

[boomdriver]

Check your tensioner pully bearing and the air pump as the source of the intermittant rattle as well.
I take the belt off and spin things by hand to feel for roughness or end play in shaft bearings that can cause a rattle. The tensioner spring can also cause a chatter sometimes.
Clutch air-gap should be about the thickness of a business card and the plate should be free to move in/out all the way around. Outside of that, a rattle there would be internal from bad rollers or shaft bearings.

additional....
just for grins I called a local parts store...and you;re right, $413 for a rebuilt. Funny thing is, they only want a $10 core charge on that, and my $200 compressor had a $25 core...lol.
Perhaps these Nipon units were designed to be repaired, so go for it. All I can add to that is be CLEAN, and work as if it were a heart surgery and I'm sure it will be alright. All compressors, gas, hydraulic or liquid, have extremely tight tolerances and contamination is the #2 reason for failure. For a $50 seal kit and an afternoon, opposed to buying new, its worth a try at home.
Good luck with it.

[joshwilson3]

Check your tensioner pully bearing and the air pump as the source of the intermittant rattle as well.
I take the belt off and spin things by hand to feel for roughness or end play in shaft bearings that can cause a rattle. The tensioner spring can also cause a chatter sometimes.
Clutch air-gap should be about the thickness of a business card and the plate should be free to move in/out all the way around. Outside of that, a rattle there would be internal from bad rollers or shaft bearings.

additional....
just for grins I called a local parts store...and you;re right, $413 for a rebuilt. Funny thing is, they only want a $10 core charge on that, and my $200 compressor had a $25 core...lol.
Perhaps these Nipon units were designed to be repaired, so go for it. All I can add to that is be CLEAN, and work as if it were a heart surgery and I'm sure it will be alright. All compressors, gas, hydraulic or liquid, have extremely tight tolerances and contamination is the #2 reason for failure. For a $50 seal kit and an afternoon, opposed to buying new, its worth a try at home.
Good luck with it.

I appreciate it. Yeah, I know the tensioner can chatter, which it does some. I had replaced that a few months ago with an OEM unit. As the PO had the wrong tensioner on there and was longer than OEM. So, it also stretched the belt out some. So, I replaced the belt a month ago when I pulled the frisbee off. Then later in the week, I went out of town. And a few days later, I noticed the oil splatter.

I had replaced the smog pump with a 45k mileage OEM unit at the end of last year. As I seized the one on my car when I cleaned the engine. I knew to pull the alternator and battery, but no one said anything about the smog pump.

Yeah, I've read the air gap is .02". And the bolt on the clutch is 10 ft/lbs. If I was to pull the clutch off to look at it, then put it back. Will it have the correct air gap if I reuse the old shims? Or would I need to get a shim kit? I figured you'd only need a shim kit if you replace the clutch, vs. just pulling the old one off and putting it back on.

The one problem of pulling the compressor, is I doubt a shop will hold the R12 they pull from my system. So that means I'd have to convert to R134, which means another $100. Probably more than that as the shops I talked to don't replace o-rings, orifice, accumulator, and flush the system. I think they just put new fittings on, and put a vacuum. Then fill with R134.

I will probably talk to the shop teacher at the local tech school to see if he feels he could replace that seal for me. I will probably have them first pull a vacuum on the system, and replace the orifice. So I can check the old one for metal. As if there is metal, then it probably wouldn't be a good idea to try replacing the seal as the compressor is probably going. But if it is clean, then I will probably try to just replace the seal. It is $25 at Autozone.

[boomdriver]

If the clutch comes off and nothing is changed, there is no reason to worry about more shims, or less. Just check the air-gap to be certain that its not too wide and it should go back together as it was.
Yes, I learned the hard way about washing smog pumps....as well as alternators.

If I were you, I'd brush up on the conversion and do it yourself. You do NOT want to say "convert it to 134-a" to a shop. They will do what is called a "firewall forward" and it hurts...I've seen that come to $1200...easily. PLUS, the shop will take the r-12 but gouge you for an "enviromental disposal fee" and special handling and that ain;t cheap. It's treated like cyanide since it is not to be resold or reused.
Conversion is really easy. the ONLY new parts you need are a dryer, 8oz of the 134-a oil, some alcohol & compressed air, or nitrogen or Co2 to blow the solvent of choice thru individual componants, and a new orifice tube. And an O-ring kit.
Disconnect the various sections, pour in solvent, blow thru and reconnect when all are clean. The compressor just needs to be drained. Do not run solvent thru there. Add oil to the new dryer, connect and evacuate the system. Then recharge with the synthetic 134-a, as it gets cold faster.
I have done several and had good results. Shops will rape customers over these conversions. It should be a crime, what they will charge. Yes, r-12 gets a couple degrees colder, but not much. Much evil has been linked to 134-a but the simple fact of life is that r-12 is slowly going away, and for $75 a lb (approx$250 per charge)you can convert and use $11 per lb gas.

[joshwilson3]

If the clutch comes off and nothing is changed, there is no reason to worry about more shims, or less. Just check the air-gap to be certain that its not too wide and it should go back together as it was.
Yes, I learned the hard way about washing smog pumps....as well as alternators.

If I were you, I'd brush up on the conversion and do it yourself. You do NOT want to say "convert it to 134-a" to a shop. They will do what is called a "firewall forward" and it hurts...I've seen that come to $1200...easily. PLUS, the shop will take the r-12 but gouge you for an "enviromental disposal fee" and special handling and that ain;t cheap. It's treated like cyanide since it is not to be resold or reused.
Conversion is really easy. the ONLY new parts you need are a dryer, 8oz of the 134-a oil, some alcohol & compressed air, or nitrogen or Co2 to blow the solvent of choice thru individual componants, and a new orifice tube. And an O-ring kit.
Disconnect the various sections, pour in solvent, blow thru and reconnect when all are clean. The compressor just needs to be drained. Do not run solvent thru there. Add oil to the new dryer, connect and evacuate the system. Then recharge with the synthetic 134-a, as it gets cold faster.
I have done several and had good results. Shops will rape customers over these conversions. It should be a crime, what they will charge. Yes, r-12 gets a couple degrees colder, but not much. Much evil has been linked to 134-a but the simple fact of life is that r-12 is slowly going away, and for $75 a lb (approx$250 per charge)you can convert and use $11 per lb gas.

I think I'd probably see about having the local tech school do it if they are set up for AC conversion before I'd try it. All I'd have to pay for is parts.

I checked the air gap, and it is .024". I believe it is supposed to be .020" air gap. Is .024" fine?

Once the front seal starts leaking, do you know about how long you have? I noticed it doesn't leak as much after I put the frisbee back on. But I did notice a slight rattle at the front of the engine after I put the frisbee back on every once in a while that I can't find. I'll have to look at it more. But I don't think it is leaking real bad, as with it running, I don't see any oil spitting, and the bottom is clean. After driving it around, there was a small spray on the tensioner and hood. After I put the frisbee back on, there has just been a small spray on the hood, probably 20 small drops last time I drove it.

Can you replace the orifice without changing the drier? I was thinking if the tech school is setup for it, I may see about them just vacuuming it out, run some tests, and replace the orifice. That way I'd know if the orifice is full of metal or not.

[boomdriver]

In regard to the air-gap....I would'nt worry. 0.004 is not much. If it engages now it will in the future. You;d be amazed at how powerful the magnetic field is from that coil behind the clutch...I've seen gaps more in the 1/8" range that did fine.

Once you start loosing oil out the shaft seal, its hard to say how long it will last. Mine failed this past winter reather quickly. I noticed oil slung around under the hood, and belt, then it started to cycle more and more due to low pressure. When it eventually failed I recharged it and it would only hold the charge for 3 days. Mine failed from an bad shaft that was wobbling just enough to effect the shaft seal. Bushings. The shaft eventually started working its way OUT of the compressor and caused me great pain with belt alignment...it ate 3 belts within 2 weeks at $45 a copy.Took me that long to figure out that it was the compressor that was coming out of alignment and forcing the back edge of the belt to chew on the edge of the pulley. Loosing the serpentine belt on the freeway miles from home "motivated" me to go ahead and buy a compressor...in January.
The beginning of that failure was the rollers inside that scattered and probably sent particles thru the system and wiped out the shaft bearings and seal. The compressor rattled a bit, then that got worse until it came apart inside. The orifice was stuck in place with a bunch of metal splinters and grit. It's hard to say how long one will last but I can tell you that its on the way out....tomorrow? next week? next month? maybe. All that is known, is that it WILL fail. That ALWAYS happens when its inconvenient....

Is it possible the belt is picking up some oil from somewhere else and slinging it around??

Once its leaking there is a very limited amount of gas to leak out. It probably leaks more when running because thats when the shaft wobbles and breaks the seal. The deal is that the oil is harder to leak past the seal, but once the oil levels go down then you start leaking gas and that goes quick because its much thinner. A leaking seal can also be an indicator of some other mechanical problems, at least with the kind of compressor on my yr vette.

[joshwilson3]

In regard to the air-gap....I would'nt worry. 0.004 is not much. If it engages now it will in the future. You;d be amazed at how powerful the magnetic field is from that coil behind the clutch...I've seen gaps more in the 1/8" range that did fine.

Once you start loosing oil out the shaft seal, its hard to say how long it will last. Mine failed this past winter reather quickly. I noticed oil slung around under the hood, and belt, then it started to cycle more and more due to low pressure. When it eventually failed I recharged it and it would only hold the charge for 3 days. Mine failed from an bad shaft that was wobbling just enough to effect the shaft seal. Bushings. The shaft eventually started working its way OUT of the compressor and caused me great pain with belt alignment...it ate 3 belts within 2 weeks at $45 a copy.Took me that long to figure out that it was the compressor that was coming out of alignment and forcing the back edge of the belt to chew on the edge of the pulley. Loosing the serpentine belt on the freeway miles from home "motivated" me to go ahead and buy a compressor...in January.
The beginning of that failure was the rollers inside that scattered and probably sent particles thru the system and wiped out the shaft bearings and seal. The compressor rattled a bit, then that got worse until it came apart inside. The orifice was stuck in place with a bunch of metal splinters and grit. It's hard to say how long one will last but I can tell you that its on the way out....tomorrow? next week? next month? maybe. All that is known, is that it WILL fail. That ALWAYS happens when its inconvenient....

Is it possible the belt is picking up some oil from somewhere else and slinging it around??

Once its leaking there is a very limited amount of gas to leak out. It probably leaks more when running because thats when the shaft wobbles and breaks the seal. The deal is that the oil is harder to leak past the seal, but once the oil levels go down then you start leaking gas and that goes quick because its much thinner. A leaking seal can also be an indicator of some other mechanical problems, at least with the kind of compressor on my yr vette.

I'm pretty sure it's from the compressor. This is what I noticed a few weeks after I pulled the frisbee off and replaced the belt. Also some on the hood:



After a week of cleaning and driving/rechecking. I put the frisbee back on. And so far no oil on the tensioner/control arm, just a little on the hood.

When you have the AC on auto 60, is the clutch supposed to be engaged the whole time? I seem to remember months ago that the clutch would kick on and off every so often. But last I idled it, the clutch stayed on the whole time.

And do you think I could have a shop put a vacuum on it, and replace the orifice without replacing the drier? I figured that way I could see how much if any metal there is. As that would let me know if it is worth just replacing the seal or expect to replace the whole thing instead.

I think I'll pull the clutch off and have a look behind it.

[boomdriver]

well, the hard part is finding somebody to handle the r-12. Most places will want a disposal fee and then possibly charge for new gas. I do not know what the policy is on draining, then re-using the old gas. It's voodoo to many places. Actually, its an excuse to charge customers for whatever they can since they will quote federal law about r-12 disposal and handling, so not many places will do favors with r-12 anymore. There are less and less that even refill r-12 systems because of the high cost of disposal and all the documentation that goes along with it. Collecting r-12 cost even more because the used gas has to be kept seperate and disposed of.
Thats why most cars that go for conversion arrive with "empty" systems....
I think I was quoted $300 just to dispose of 2 lbs of r-12 and that was several yrs ago.

There is no reason to replace a dryer unless the system is contaminated, or being converted. you cannot use a r-12 dryer with 134-a gas & oils. It will gum up and clog the system and kill it. In fact, there is a different orifice for 134-a but its not an absolute "got-to" have for conversion. A new r-12 orifice or the clean old one will work.

When you set auto to 60 that over-rides the airbox controls and goes to full cold, so the comp would stay on more. Set it to 68 and it will try to cycle on/off as needed, and adjust thru the airbox hot/cold air mix door.
Same goes for 90...it overrides the system and goes to full heat. Anywhere between 60 and 90 allow for air mix.
The compressor not only shuts off when the pressure gets too low, it also kicks out if the pressure gets too high. Its hard to tell which it does unless you jump the low pressure switch and see what happens. If it does not cut out then the system is running low. If it does cut out then its the high pressure safety switch thats being activated. When you jump the low pressure switch, that takes low pressure out of the equasion as far as the cycling is concerned. Don;t run it too long like that, just a couple minutes. never run it with the high press switch jumped...it could blow apart and the gas can be quite cold when things come apart in your hand....

[joshwilson3]

well, the hard part is finding somebody to handle the r-12. Most places will want a disposal fee and then possibly charge for new gas. I do not know what the policy is on draining, then re-using the old gas. It's voodoo to many places. Actually, its an excuse to charge customers for whatever they can since they will quote federal law about r-12 disposal and handling, so not many places will do favors with r-12 anymore. There are less and less that even refill r-12 systems because of the high cost of disposal and all the documentation that goes along with it. Collecting r-12 cost even more because the used gas has to be kept seperate and disposed of.
Thats why most cars that go for conversion arrive with "empty" systems....
I think I was quoted $300 just to dispose of 2 lbs of r-12 and that was several yrs ago.

There is no reason to replace a dryer unless the system is contaminated, or being converted. you cannot use a r-12 dryer with 134-a gas & oils. It will gum up and clog the system and kill it. In fact, there is a different orifice for 134-a but its not an absolute "got-to" have for conversion. A new r-12 orifice or the clean old one will work.

When you set auto to 60 that over-rides the airbox controls and goes to full cold, so the comp would stay on more. Set it to 68 and it will try to cycle on/off as needed, and adjust thru the airbox hot/cold air mix door.
Same goes for 90...it overrides the system and goes to full heat. Anywhere between 60 and 90 allow for air mix.
The compressor not only shuts off when the pressure gets too low, it also kicks out if the pressure gets too high. Its hard to tell which it does unless you jump the low pressure switch and see what happens. If it does not cut out then the system is running low. If it does cut out then its the high pressure safety switch thats being activated. When you jump the low pressure switch, that takes low pressure out of the equasion as far as the cycling is concerned. Don;t run it too long like that, just a couple minutes. never run it with the high press switch jumped...it could blow apart and the gas can be quite cold when things come apart in your hand....

Ok, thanks. That does suck since I've got cold air. But I may see if the local tech school could pull it out, and put it back in. I don't see why a shop wouldn't do that since places still sell R12 for use. I've always been told that the shops get good money on R12 that they pull?

The one problem with the local shops that I talked to is that they don't replace Orings and the drier. Not sure on the orifice or not, but I doubt it. It just sounds like they just put on new fitings, and replace what is in there. I told this one guy I talked to that you have to replace the drier on a conversion, but he said that you don't need to and has been doing AC for 30 years. Another shop said they don't replace things like orings, drier etc. because they say people don't want to pay for it.

[boomdriver]

Its the disposal that cost so much. Many shops do not have the equipment to recycle and they have to use new gas to recharge a system. Some have equipment dedicated to r-12 and can do it, but they are becoming few and far between as the demand for r-12 service slowly vanishes.
Replacing the dryer is a basic. I dunno what that dudes training is, but thats the first thing to do when converting because the dryer holds a bag of chemical to absorb moisture, and it is where most of the oil is stored. It cannot be washed out and the oil from a r-12 system will not mix with 134-a oil. It turns to mud. Maybe a small amount might be ok, but with the investment of a compressor and the work to change O-rings and do it right, another $75 for a new accumalator/dryer is cheap insurance for a system that will last. Thats also a reason why half assed jobs fail and the rebuilt compressor gets the blame. Failing to properly clean a system assures early failure. I could not even register my compressor warranty until I bought the dryer and new O-rings. If these shops did'nt abuse their customers with outragous prices for a/c service they would be seeing more people willing to pay for new parts. A/c work has always been a hi-dollar service because most people are afraid of it. Its so simple that anyone capable of changing spark plugs, can convert a system successfully. The number one thing is to be clean. Dryers can;t be cleaned, thats why they get replaced.

[joshwilson3]

Its the disposal that cost so much. Many shops do not have the equipment to recycle and they have to use new gas to recharge a system. Some have equipment dedicated to r-12 and can do it, but they are becoming few and far between as the demand for r-12 service slowly vanishes.
Replacing the dryer is a basic. I dunno what that dudes training is, but thats the first thing to do when converting because the dryer holds a bag of chemical to absorb moisture, and it is where most of the oil is stored. It cannot be washed out and the oil from a r-12 system will not mix with 134-a oil. It turns to mud. Maybe a small amount might be ok, but with the investment of a compressor and the work to change O-rings and do it right, another $75 for a new accumalator/dryer is cheap insurance for a system that will last. Thats also a reason why half assed jobs fail and the rebuilt compressor gets the blame. Failing to properly clean a system assures early failure. I could not even register my compressor warranty until I bought the dryer and new O-rings. If these shops did'nt abuse their customers with outragous prices for a/c service they would be seeing more people willing to pay for new parts. A/c work has always been a hi-dollar service because most people are afraid of it. Its so simple that anyone capable of changing spark plugs, can convert a system successfully. The number one thing is to be clean. Dryers can;t be cleaned, thats why they get replaced.

If I got a shop to suck the R12 out, can I then drive back home with no freon? I figured I could at least do that, then replace the Orings and orifice myself. Then bring a new drier and have them replace the drier and flush the system. Run checks and refill with R134.

The only thing is I'd be afraid of tightening the tube too tight.