a/c compressor

Post by **natsoundup** » Mon Aug 18, 2003 6:07 am

When replacing the A/C compressor do you have to disconnect the lines from the compressor...or do you un-do the lines from the top and just slide the compressor off...

Does it matter...or is it easier one way or the other?

I am considering doing this job since I have much of the front of the engine pulled off... The drier is free, since I took out the radiator.

Pulled the thermostat..couldn't believe how new it looked for 13 years old and how heavy it was...

1990 Q 156 k miles.

Post by **forecast** » Mon Aug 18, 2003 6:07 am

You can disco the hoses at the compressor.

The big question is why? To replace the drier. OK

Is there something wrong with the AC right now?

If you want to change the drier, I'd recommend you have it done where they can store the R12 and do all vacuming needed.

R12 is costly enough that under no circumstance should you just vent it to atmosphere to hurry up a job.

Unless you really have to, you don't want to change the system to r134 since the effectivness will drop.

Post by **natsoundup** » Mon Aug 18, 2003 6:07 am

The compressor locked up.... so I am doing a lot of other work myself and the drier is in eyesight...so is the compressor....

I will then take it to a place to vacuum the lines and do the r-12.

Post by **Q45tech** » Mon Aug 18, 2003 6:07 am

Just make sure the dryer is not exposed to the atmosphere for more than a few minutes before vacuuming the system........the dessicant degrades rapidly in the presence of air moisture.

Post by **Q451990** » Mon Aug 18, 2003 6:07 am

When I replaced the evaporator in my truck I borrowed a vacuum pump and pulled a vacuum with the old dryer in place - just to make sure everything was sealed correctly. I replaced all of the o-rings, evaporator, drained the oil out of the compressor, etc. Then, after confirming that it would hold (stayed at -30psi for about 30 minutes) I swapped the dryer and vacuumed for 48 hours. I only intended to do it for 24, but didn't have time after the first day so I just let the pump keep on running...

My point being, you may want to have the place that's recharging check it first for air tightness before putting in the new dryer - it's pretty easy to access...

Heath

Post by **Q45tech** » Mon Aug 18, 2003 6:07 am

Usually 30 minutes of vacuuming is enough, many speedy shops do 15 or less. recharge and oil weight EXACTNESS is critical to getting every possible degree of drop without overcharging [even 5%] which can cause a temperature rise once the system has been running for 20-30 minutes on the highway.

Post by **natsoundup** » Mon Aug 18, 2003 6:07 am

does the A/C compressor have more than 3 bolts to remove...

I have unbolted two underneath.... and one on front....... I seem to be hung up in trying to get it out...

the a/c lines were easy to unbolt..

Post by **natsoundup** » Mon Aug 18, 2003 6:07 am

I think I found the fourth bolt...in the back up into the compressor...

What kind of tools does it take to access this bolt...I am stymied

Post by **Q451990** » Mon Aug 18, 2003 6:07 am

Just looked at that one myself - nothing like having a reference car on jack stands in your garage. Maybe you have to unbolt the tie-downs for the high pressure power steering hoses, or use a really long extension and fish it through from the other side of the crossmember that supports the engine? I'm looking forward to seeing what someone who's actully done this recommends too!

Heath

Post by **natsoundup** » Mon Aug 18, 2003 6:07 am

I'll impatiently wait....actually my compressor won't be here until tomorrow or Thursday...

Post by **Q451990** » Mon Aug 18, 2003 6:07 am

If your compressor locked, you may want to think about flushing the lines, condensor, and evaporator. Sometimes compressors spew shavings and parts when they self destruct, so getting that stuff out is important.

Heath

Post by **natsoundup** » Mon Aug 18, 2003 6:07 am

c'mon....somebody must know what combination of tools it takes to get the rear upper bolt off the compressor.

I am counting on you guys.

Post by **Q451990** » Mon Aug 18, 2003 6:07 am

You might try calling Joe or a dealer there in Greenville. I've had some luck getting brief technical advice that way...

Heath

Post by **natsoundup** » Mon Aug 18, 2003 6:07 am

e-mailed Joe...thanks for the suggestion.

Don't have much faith in the techs here at Infiniti of Greenville.I just would hate to put the front of the car back together and pay someone to take out the compressor.

Post by **forecast** » Mon Aug 18, 2003 6:07 am

I use 3/8 drive ratchet and short 14 mm socket. common enough tool

Getting it in place is a learned trick though.

I'm happy to help, but I don't check the board every day.

Post by **natsoundup** » Mon Aug 18, 2003 6:07 am

Thanks forecast for the reply...

There doesn't seem to be enough room for a 3/8 inch drive...what kind of extension do you use...

I was going to try my 1/4 inch drive with the 14 mm socket, a swivel...and a long extension..

due to my schedule I haven't had a chance to crawl under in a day or so... I think my compressor will arrive today or tomorrow...

Post by **forecast** » Mon Aug 18, 2003 6:07 am

Push the wiring harness out of the way, you may need to disconnect where the wiring harness attaches to oil pan tie down to get enough slack.

you will snap you 1/4 drive this is supposed to be about 40ft/lbs.

As for the wrench... just standard ... I normally don't let strangers look at my tools but...

Post by **natsoundup** » Mon Aug 18, 2003 6:07 am

thanks... i'll see what I can do...

Post by **Q451990** » Mon Aug 18, 2003 6:07 am

I looked at this again with a better light, and I think by disconnecting and moving the harness aside, and disconnecting that power steering hose tie down brackets (that makes a "U" shape) to get better access.

Heath

Post by **natsoundup** » Mon Aug 18, 2003 6:07 am

I am going to go after it tonight.....the compressor came yesterday...

Post by **natsoundup** » Mon Aug 18, 2003 6:07 am

Success so far..... Heath....your suggestions work...and forecast...the 3/8" ratchet worked.... still a pain getting that last bolt out.....and back in....

The compressor is not shipped with oil..... the old compressor said it took 10 oz.... the under the hood sticker said 8..... I put in a little more than 8...

I did make a mistake ...forgot to order the o-rings from Joe...so I go to the dealer....he has only two of 6 I needed....they will be here Monday....go figure....tried to match them up at Pep Boys...won't take a chance...

Since there was room.... I messed with the alternator a bit....I tried the Superglue gel trick....it worked..although I had the space to get it back on.....

Put the new pulley on.... and some belts ...still have to put the new thermostate, fan, and hoses in...then re-install the radiator...oh and the new drier....

I figured I am saving a good 700-800 dollars in labor doing all this stuff..

My biggest fear is that I just should have gone ahead and replaced the original alternator and water pump while I had a wide open view....oh well..

1990 Q45 156k miles

Post by **Q45tech** » Mon Aug 18, 2003 6:07 am

http://xp20.ashrae.org/ABOUT/sept99.pdf ... /l...c.pdf

Post by **natsoundup** » Mon Aug 18, 2003 6:07 am

Tech---- I enjoyed the first read (not so techinical)

You are usually not a man of so few words......

I figure I am paying myself about a thousand bucks with all the work I am doing......

....if it wasn't for the good people on this board it would not be possible.......

Post by **Q45tech** » Mon Aug 18, 2003 6:07 am

I try to sucker you in with the easy pictureful reads.

Owners of 90-95-even 2004 cars don't realize how easy they have it, just wait till the super critical carbon dioxide AC comes into use.

a/c compressor

a/c compressor

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