Write-Up: AC Compressor & Clutch Replacement

yep al i used them when i had to replace the ac unit in mine last summer. buy one with a gauge its worth the extra few bucks as long as its the reusable one. kinda looks like a tire lol. mine blows artic cold with no probs

joshuadalegrimes wrote:

yep al i used them when i had to replace the ac unit in mine last summer. buy one with a gauge its worth the extra few bucks as long as its the reusable one. kinda looks like a tire lol. mine blows artic cold with no probs

Thanks Joshua, I'll give it a try!

Al

I'd check one thing before you charge the AC. Make sure the sensor to the air filter box is plugged in and not damaged. If the IAT sensor is disconnected or damaged, it will cause the AC to switch on/off in a seemingly random fashion. Good luck!

Quick question about the A/C compressor clutch gap. Watching some online videos and other references, the air-gap between the clutch plates for a GM unit is .020 to .035. I set mine to .027,but after running it a bit and having the clutch engage correctly, I see that the gap has closed to a very very narrow gap, I'd guess .020 or less.

I looked at the same clutch on my 95 Roadmaster and it too is a very very close gap.

So I'm wondering if the spec is to set the gap at .020 to .035 and then the plate auto adjusts and closes and maintains the gap to just a hair's width automatically as it is used?

I was expecting the .027 gap to remain, but looking at my Roadmaster clutch, maybe that is a false assumption.

What gap do your compressor clutch plates exhibit once in use?

Thanks
Al

Mine was actually closer to .040 when I installed; it was still able to lock up just fine. I think over time the gap may have gotten slightly smaller. Looks that way. I would rather have the gap on the large side than risk it rubbing. In theory it could rub a little - should even out over time.

My mechanic said it can close up a bit after installation, but as long as it isn't dragging then it is fine.

Al

An update: It's been about a month since I installed the A/C clutch, and the gap apparently was a bit too wide. I had noticed that the "slap" of the compressor was very loud and pronounced. After re-measuring the gap I found it to be well over .030" which is beyond the .020-.030" recommended gap for this compressor.

I was fairly certain I had installed it within that spec, but either I mis-measured or the gap opened. Hard to say for sure, but I suspect my own user error is more likely

So I re-rented the compressor clutch puller/installer kit again, and tightened up the gap to .021" and after driving for a week I can definitely tell that the engagement is quieter and there is no drag.

But here's something interesting: The gap has now closed up a bit on its own under .020". I found this to be true on my 95 Roadmaster's compressor clutch gap as well, where it was under .020". I think this may be just how these press fit clutches work, where you install them to spec and they auto adjust to some degree to find their gap "sweet spot".

The clutch isn't dragging at all and is engaging just fine. I asked my mechanic about it and he basically said it doesn't matter as long as it isn't dragging.

I guess when it was way over spec it couldn't close that gap though, perhaps just being too far out.

Al

So my car was making an loud grinding noise when running coming from the ac pump and the ac did not work at all. So we looked at one of my dad's parts cars to see if we could use one off of there. We found one that worked and it didn't make that loud noise.

We removed my old a/c pump and put this new(used) one on. We then took it to our mechanic to have the system recharged. The system has been charged up to 75% but the clutch is not engaging so he can't charge it all the way. What would cause the clutch not to engage in my car?

This new(used) a/c pump worked before. No oil drained in the process of removing this new(used) one we made sure. Please help my dad is trying to get my car ready to be shipped over to me in Hawaii. He checked all the fuses as well.

I am going to take the climate control unit apart and fix the dimming issue and see if there is anything else going on inside there to cause this issue when it get here

I'm having problems with my a/c compressor. When I turn the climate control on and open the hood, my compressor is making a lot of noise when engaged. It stays engaged for a few seconds, then disengages and sounds normal. Then a few seconds later, it engages again and has a lot of noise. It goes in like 15 second intervals. When I go inside the car, the air coming through the vents starts to cool when the compressor is engaged, and then heats back up when I hear it disengage. It's never engaged long enough to really blow out cold air, but it was in the 70's today and it was blowing out a little colder than the air outside.

Any ideas as to whether I'm going to need a whole new compressor or what exactly might be wrong with it? I just did a full coolant flush and switched from orange to green. The few weeks of warm weather before that I didn't run my a/c because i was having cooling problems, so I don't know exactly when this happened. Low coolant light was turning on but when going to fill my radiator I noticed a bunch of white gunk which looked a lot like what you would see if you combined antifreezes. That's why I did the full flush. My car was blowing really cold last summer.

Any help would be great. Car is at 220k miles with the only engine mods being zzp 15mm wires, and a gutted airbox.

Sounds like at the very least your A/C refrigerant charge is low. That generally means you have a leak somewhere, so just filling it back up MAY not help for long. Unless you know your way around an automobile A/C system and have the right tools (not that cheap refill/leak-stop stuff from the auto parts store) then this is one I'd recommend you take to an A/C shop and have them check.

One aside is that I've had many shops tell me my compressor is bad, or leaking and refilling with refrigerant is just going to leak back out in a year. In all my examples, the system has held for years following a proper evacuation and refill. But that is just my experience, others may certainly vary based on the type and significance of the leak. But my strategy has been to have them refill it and give it a try and see. If it leaks right out, yep you're out some $ for the failed refill, but OTOH if it holds you are good until the compressor, etc actually dies.

I had a similar issue on my 95, where I replaced the clutch and then had the system refilled. I was told it may all leak back out as the seals probably got cooked in the compressor, but "knock on wood" a year later the A/C still cools fine.

Now my compressor is still too noisy IMHO, so I suspect it will die at some point. But I'll run it until it does

Al

Al's advice is good. A full evacuation will also tell them if the system can hold a vacuum at all - if the system doesn't hold a vacuum, it has a big enough leak that you know it's not worth filling. At point either the leak should be obvious or else they will fill it along with a dye. Come back a week later to have the dye inspection - it's ultraviolet and requires a blacklight to see. (not really, it's a very bright yellow)

Even after all this, my dad still has to add a can of freon every couple of months to my old Yukon down in Florida. He had the rear evaporator replaced (obvious dye showing there) and it still has the same slow leak it had before. No evidence of a compressor leak, but for him a can of freon every few months is cheaper than a compressor (not in the long run, I know I know).

A little thing that hasn't been mentioned. The A/C clutch WILL cycle on and off continuously, even when the system is full. Whenever the pressure in the A/C system gets low is when the compressor kicks on...so obviously more when the charge is low. If the compressor is making a horrible noise when it's engaged, chances are the compressor is failing internally, spreading metal shards throughout your A/C system. Can you throw a can of R134 in it to see if it helps? Absolutely. I'm just sayin, don't be surprised if the compressor is in fact bad. They aren't supposed to be extremely noisy. Even if the system was empty, the PCM wouldn't even turn it on, so there's something in there.

FYI...when a compressor fails internally, it will fill the whole system with metal (as stated above), especially the Orifice Tube and the Receiver/Dryer. The Orifice tube needs to be replaced, and the system needs to be flushed with A/C system cleaner otherwise the new Compressor will inevitably fail.

Hi all, I need some opinions. My AC clutch is going out, but I don't have time to replace it before I do a road trip tomorrow (about 500 miles round trip, Toledo to Cincinnati and back). I looked in the engine bay and there are metal shavings here and there near it.  The clutch isn't engaging when I turn on the AC, as I think I've lost enough R134a to where it's just not engaging at all anymore, so it's making that metal ringing noise all the time.

I'm wondering if you think it's safe for me to drive, or if the clutch might seize up on the road (do not want!). I can always drive my Firebird (which also has no AC), but it's supposed to rain and I try to not drive it in the rain. Plus I just waxed it.    Thoughts?

gunmetalRED wrote:

I'm wondering if you think it's safe for me to drive, or if the clutch might seize up on the road (do not want!). I can always drive my Firebird (which also has no AC), but it's supposed to rain and I try to not drive it in the rain. Plus I just waxed it.    Thoughts?

That thing could lock up on you tomorrow, or it could lock up 3 months from now. There's no way of telling how long it will last like that. It's one of those things that goes when it goes.

Agh, that's what I kinda figured. Thanks! I guess I'd rather risk driving in rain than having it lock up in the middle of nowhere.

Worst case scenario you switch the climate to "Eco" (Vent) and the A/C won't run. Other worst case is you reach down and unplug the A/C compressor so you can switch the airflow to defrost. People drove for years without A/C compressors and still made it through the rain!

The car I'm being stubborn about driving in the rain is actually my Firebird-- I try not to get it wet (yeah I'm one of those people) and I just waxed it, haha.  I'm just afraid my Riv's AC clutch will lock up on a road trip this weekend (Murphy's law says...)

Soooo I just ordered the Delphi compressor/clutch assembly and all the other goodies from Amazon (free shipping and the ACDelco compressor is only $169!).  I figure for an extra $70 I might as well just replace the compressor with the clutch. Mine blows cold air when it works, but is starting to whine a little... and I'd rather just do this job only once, ha.

Hey guys, I've been getting this intermittent, higher pitched noise coming from the engine bay ever since I bought my Riv. A friends dad noticed metal shavings around the A/C compressor pulley and I ignored it a little bit because I don't use the A/C. Prefer to drive with the window down. Anyways, today my uncle was looking down there and said that the A/C pulley should be spinning. It wasn't at all! We started smelling burning rubber, so we shut the car down. I'm thinking about getting an A/C bypass pulley, but I have no idea of knowing if there's any refrigerant still in the system. I don't want to risk driving to a shop to get the refrigerant out because the A/C pulley has totally locked up. I really don't want to be stranded on the side of the road because of a broken belt.

Why isn't the pulley spinning? Is it because of the clutch? If so, is there a way to get the clutch to engage so I can make it to a shop? I'm not versed on all this A/C stuff, so any help and/or information is appreciated.

KnottyEagle wrote:

Hey guys, I've been getting this intermittent, higher pitched noise coming from the engine bay ever since I bought my Riv. A friends dad noticed metal shavings around the A/C compressor pulley and I ignored it a little bit because I don't use the A/C. Prefer to drive with the window down. Anyways, today my uncle was looking down there and said that the A/C pulley should be spinning. It wasn't at all! We started smelling burning rubber, so we shut the car down. I'm thinking about getting an A/C bypass pulley, but I have no idea of knowing if there's any refrigerant still in the system. I don't want to risk driving to a shop to get the refrigerant out because the A/C pulley has totally locked up. I really don't want to be stranded on the side of the road because of a broken belt.

Why isn't the pulley spinning? Is it because of the clutch? If so, is there a way to get the clutch to engage so I can make it to a shop? I'm not versed on all this A/C stuff, so any help and/or information is appreciated.

The compressors and clutches are pretty common repair/replacement items. A/C is built into the car, it's part of the automatic climate control. If you want to remove it and put in a bypass pulley you'll have to get a that before you get it towed to a shop. You can't drive it there without a belt, and then you'd need to get it towed back home since the belt routing requires that something be in that place. So at this point you have to either a) repair the clutch/pulley or replace the compressor or b) order that A/C delete pulley overnight...

How do the two lines going into the back of the compressor come off? I see there's a nut, but didn't know if I would have to pry the lines out or if they just slipped out after that nut came off.

Take that nut off and pull. You might have to pry a little bit, but don't bend anything.

Abaddon wrote:

Take that nut off and pull. You might have to pry a little bit, but don't bend anything.

Cool. I got it broken loose for now. I'll finish this up tomorrow.

When I did this the pulley puller wouldn't work with the compressor in the car so I pulled it. The threads in the clutch for the puller were rusted and full of grime and it wasn't happening.

I had my mechanic replace my compressor, orifice tube, and dryer two years ago at 77,000 miles. My old compressor had leaked and needed replacement. I got a Denso compressor at RockAuto and my mechanic replaced it. Now, 2 years and 5,000 miles later the compressor blows cold but is rattling when the AC is engaged, sounds like there are rocks in the compressor and is getting worse. The compressor only had a one year warranty so I need a new one. What should I get? At RockAuto there are several options:

Delphi.
Four Seasons.
AC Delco Professional advantage.
AC Delco original OEM replacement.

Which compressor should I get so I don't spend anymore $$$ on this? I will also have my mechanic flush the system this time. I don't think he did this last time since everything leaked out and it was dry.

Thanks for your advice!