A/c Compressor

[RFeldes]

What is the easy way of going about replacing the compressor. Above or below? Any lessons learned out there? Thanks

[Lextreme]

Lesson? Its too easy that is why no one really write about it. There are three 14mm bolts. One on top and two at the bottom. U also need to slowly bleed the freon and remove the two lines along with two electrical plugs. U gotta remove the fan belt first. The fan belt is held by a 14mm belt tensioner.

U need to jack the car up inorder to access the two 14mm. The job will take about 30 minutes. Most of the time, clutch is the one that broke.

david

(spelling)

What is the easy way of going about replacing the compressor. Above or below? Any lessons learned out there? Thanks

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[RFeldes]

Thanks for your help David.

[cruznroadking]

I know i've mentioned in other a/c posts. Be careful not to get freon in your eyes. Wear eye protection. Freon in your eyes will make you go blind.

[RFeldes]

Hi cruzinroadking,

The system is void of freon now and I am grateful for the advice and will be careful. Thanks for your input, as it is a very important piece of advice for us all.

Always better safe than sorry, and eye protection is always important especially under the vehicle. Auto parts are available, but human parts are harder to find and more expensive than Lexus parts.

[Lexls]

How do you add the coolant stuff once you've got a new compressor in? Do you have to bring it in to get the system charged?

[monarch]

You have to hook up a vaccuum pump (Autozone apparently rents them) and draw a deep vaccuum on the system to remove system moisture and then charge the refrigerant into the vaccuum.

The vacuum pump is not needed if the system still retains part of its charge because no moisture will have entered and contaminated the system. All a partially charged needs is to be topped off like this: http://www.saber.net/~monarch/acrecharge.jpg

[larryp]

Replaced mine last week in my 91. THere are 3 14mm bolts. You can't get it out from above unless you take half the car apart. Get it from underneath. I had to remove the oil filter bracket to make enough room to get it out (even then it's still tight) - the stabiluzer bar is in the way. Good time to replace your drive belt if it's worn.

[POS]

Be prepared to do the job twice if you don't know what you're doing. The biggest deal, by far, is flushing the old system. If you're replacing the compressor, you need to replace the drier and the expansion valve, you need to flush the crap out of the system, and really flush the crap out of the condensor.

If you don't do all this, there are high odds that you'll put the system back together, it'll work for a few months, then the compressor will fill up with residual crap and fail on you again.

Happened to me, and it's happened to a lot of people on this board and others.

[monarch]

The biggest deal, by far, is flushing the old system.  If you're replacing the compressor, you need to replace the drier and the expansion valve, you need to flush the crap out of the system, and really flush the crap out of the condensor.

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Good point, but can depend on whether or not the compressor actually blew up internally or not.

There are two other reasons a compressor may not run even though it has not blown up.

1. If the refrigerant level is too low the compressor won't run.

2. The magnetic clutch attached to the compressor can screech and smoke and fool the owner into thinking the compressor blew up. If just the magnetic clutch fails it can be replaced.

I have found 400,000+ miles of troublefree Toyota compressor life is possible if the following (mostly Toyota provided) operational guidelines are followed:

1. Run the compressor at least once a month and preferably once a week throughout the year for at least 30 seconds and preferably at least 5 minutes.

2. When first starting the compressor after it has been not been used for a week or more, turn it on only when the engine is at low idling speed - don't turn it on during engine warm up, acceleration or at freeway speeds. (because lubricating oil drains out of the compressor when not in regular use)

3. Run the compressor manually for interior cooling as needed, but do not keep the AC controls continuously in Auto mode as Auto mode results in almost continuous compressor operation resulting in more rapid wear of the compressor and magnetic clutch.

4. Periodically check the refrigerant sight glass to make sure the system is not under or overfilled

with refrigerant and add refrigerant soon if it gets low.

5. Every year or two clean the dust and bugs off the fins of the AC condenser and radiator

with compressed air or low pressure water and detergent.

[RFeldes]

The compressor still runs. I believe it has a bad seal as the freon may last two months or overnite. Average 3-4 days. That tells me when the car stops, the amount of leakage is dictated by the compressor position on the belt. I know that the seal can be replaced but I also get an intermittent flashing a/c light which means it hangs sometime. Since I have to pull it anyways, I figured I would go ahead and replace it, the drier, expansion valve and "O'" rings and convert to 134. Then fix the old one, if it turns out to be the seal, and shelve it as a spare.

[Kennyr]

The compressor still runs. I believe it has a bad seal as the freon may last two months or overnite. Average 3-4 days. That tells me when the car stops, the amount of leakage is dictated by the compressor position on the belt. I know that the seal can be replaced but I also get an intermittent flashing a/c light which means it hangs sometime. Since I have to pull it anyways, I figured I would go ahead and replace it, the drier, expansion valve and "O'" rings and convert to 134. Then fix the old one, if it turns out to be the seal, and shelve it as a spare.

←

Are you using an elerctronic leak detector? That's the way to find the leak. Look at the port next to the fill valve directly under the cruise control unit. If its dirty or wet that's a simple o-ring that goes bad. I wouldn't be replacing the compressor without determining where your leak is coming from first.

[monarch]

RFeldes, just as you know Toyota sells "reseal kits" for the LS400 power steering pump, it also sells reseal kits for the AC compressor.

Planned obsolesence is not the Toyota way of doing business. Instead, Toyota supplies reseal kits for PS pumps and AC compressors, starter contact kits for starters, alternator brush kits for alternators, shift control solenoids for the automatic transmission, replacable magnetic clutches for the AC condenser, etc. because these components are all actually built to last 400,000+ miles or 30+ years. Not the case with American cars.

[RFeldes]

Thanks, Kennyr I did check that ring ands its okay.

Thanks,Monarch I know about the kits and that's how I would repair the old compressor if in fact it is the seal. But, Since I heard a "crunch" from the compressor a while back and it does quit intermittently with the blinking green light and I have to raise it above 2500 rpm to get it to stay on. I decided to just replace it anyway and go from there.

[Lextreme]

This link might help How To Replace A/C Compressor

[RFeldes]

Thank you Lextreme!!

[Zim]

The biggest deal, by far, is flushing the old system.  If you're replacing the compressor, you need to replace the drier and the expansion valve, you need to flush the crap out of the system, and really flush the crap out of the condensor.

←

Good point, but can depend on whether or not the compressor actually blew up internally or not.

There are two other reasons a compressor may not run even though it has not blown up.

1. If the refrigerant level is too low the compressor won't run.

2. The magnetic clutch attached to the compressor can screech and smoke and fool the owner into thinking the compressor blew up. If just the magnetic clutch fails it can be replaced.

I have found 400,000+ miles of troublefree Toyota compressor life is possible if the following (mostly Toyota provided) operational guidelines are followed:

1. Run the compressor at least once a month and preferably once a week throughout the year for at least 30 seconds and preferably at least 5 minutes.

2. When first starting the compressor after it has been not been used for a week or more, turn it on only when the engine is at low idling speed - don't turn it on during engine warm up, acceleration or at freeway speeds. (because lubricating oil drains out of the compressor when not in regular use)

3. Run the compressor manually for interior cooling as needed, but do not keep the AC controls continuously in Auto mode as Auto mode results in almost continuous compressor operation resulting in more rapid wear of the compressor and magnetic clutch.

4. Periodically check the refrigerant sight glass to make sure the system is not under or overfilled

with refrigerant and add refrigerant soon if it gets low.

5. Every year or two clean the dust and bugs off the fins of the AC condenser and radiator

with compressed air or low pressure water and detergent.

←

Regarding step #4 - where is the sight glass on a 94 SC400?

Thanks

Zim

140k

94 SC400

[VBdenny]

So if my A/C doesn't work and the A/C never flashed, it could just be a leak? I have the R-12 so that isn't a problem.

Is there a sightglass on a 90LS?

Thanks

[pachocco1]

On page AC-21 it shows the sight glass in the front of the radiator/condensor. It may be dirty and requiring cleaning to get a good visual if the R12/134a. Compressor removal and seal replacement is also documented. Have fun.

coolings.pdf

[larryp]

There's also a sight glass on top of the receiver drier that is much easier to see than the one on the condensor. You have to remove the right headlight to see it though.

[VBdenny]

Thanks for the great info, Haven't had a chance to get to it yet, something always comes up. Had to put a lower ball joint in my Caprice today, lots of fun for only $9.99

[VBdenny]

pachocco1 Great file, thanks, exactly what I needed.

Denny

[RFeldes]

Thank you guys for all your input, but a "Murphy" is always around, I got a new compressor and replaced the old one. Alas, still a leak, but my wise mechanic found the leak on the high pressure hose "under" the compressor. What was happening was the freon and oil were spraying onto the compressor in turn making the compressor slip on the drive belt and giving the blinking light for RPM malfunction.

What a circus, as the high pressure hose was less than $200 and the compressor was $350 plus labor $300. Anyway I have a new compressor and new drier $50 along with vacuum and R134. I am happy to report all is well and I'm cool at last.

LESSON: That high pressure hose under the compressor goes out frequently and causes ac failures. By frequently I mean on an LS at 90k miles. What a car!!

We actually put the electronic snifter on the compressor from above and found a leak and thought it was the compressor when in fact, it was coming from underneath. So, my advice is to always check that high pressure hose from under the car. Hope my lesson will save someone some money. Thanks for your help.

[VBdenny]

I wil gladly take that advice when I check. My neighbor has a sniffer so I will be using that. Sure is nice to know these things in advance.

[jadecuir]

I had the same problem, sort of, with my '90 LS. The system stopped working, and I took it to a local AC shop. Diagnosis: bad compressor. I put off repairs for almost 2 years. Then, a friend with AC knowledge and equipment helped me check it out. After recharge and oiling of the system, I've had no problems for 3 months now. The only thing we can figure happened is a leak at one of the valves; there were no caps on any of the three valves! There are now.