AC Compressor

[frank rabbets]

Yes up down or sideways play describes it. It's not like a buckled cycle wheel.

I can't see much movement on the video.

 

[silvercruiser]

No its not much movement, and it all still works as it should its just the bearing noise that concerns me.

 

[frank rabbets]

The main bearing is locked when the a/c is on and won't be turning therefore that won't be what's making the noise.

 

[silvercruiser]

The main bearing is locked when the a/c is on and won't be turning therefore that won't be what's making the noise.

Now im Confused

In my head i see it that when the aircon is off (unlocked) it runs on the bearing on the front pulley so that bearing is all ok as when off, its all good, and then when the aircon is on and the magnetic clutch locks in and the whole spindle turns the compressor and i thought the main spindle would have an internal bearing which would now be turning and making the noise because its got play in it? or am i missing something?

 

[frank rabbets]

What you describe is exactly how the pump works. Sorry for confusing things with the wobble. The wobble itself might be causing the noise but mine was visibly really bad and was silent. As you say it might well be the bearings inside the pump which are noisy. You could try turning the front clutch plate and shaft round by hand with the engine OFF. This should not feel notchy. Also it should smoothly tighten up as the pistons compress the gas. If the spindle turns freely the pump is not working properly.

 

[StarCruiser]

The main bearing is locked when the a/c is on and won't be turning therefore that won't be what's making the noise.

Won't the pulley still be turning on the bearing Frank? As the bearing is between the pump nose which is static and the pulley, just with the clutch plate pulled in and engaged with the pulley?

 

[silvercruiser]

Well, i have bit the bullet and ordered a new compressor.

 

[frank rabbets]

I'll have to look at my bits and pieces to check Richard.

 

[frank rabbets]

Yes you're right Richard. I still think the noise must be the compressor as silence when not engaged.

I think a new compressor comes with a full system charge of oil doesn't it ? I wonder if they allow for the oil left in the system as not all comes out with the old compressor but spread around the system.

 

[silvercruiser]

once its swapped out il be stripping the old one to see what was making the noise.

 

[silvercruiser]

Yes you're right Richard. I still think the noise must be the compressor as silence when not engaged.

I think a new compressor comes with a full system charge of oil doesn't it ? I wonder if they allow for the oil left in the system as not all comes out with the old compressor but spread around the system.

Will it hurt the system having a bit too much oil floating around?

 

[frank rabbets]

I don't think the extra oil will hurt. There may well be fitting instructions with the new one. There is no easy way to get the old oil out. For a start it clings to the inside walls of the condenser tubes. I washed mine out with deagresaer to get the debris out and then I had to get all the degreaser out using a hair drier on the fins. The condenser got hot and smelly then suddenly very cold as the degreaser suddenly evaporated. Not much debris came out so I would think with yours to put a genuine drier/filter on and you should be fine but Richard may have a view on this. None of my debris had even got to the drier/filter and it was certainly a bad break up as you can see from the pictures.

 

[Dave]

You drain the old oil from the old compressor, and measure the amount. You then drain the new compressor, and replace the same amount of oil as came from the old compressor. Preferably use new fresh oil, and not the stuff you drained from the new compressor. Depending on what else gets replaced/flushed, then the amount going back into the system gets adjusted accordingly.

 

[silvercruiser]

Thank you for all the Info.

 

[StarCruiser]

You drain the old oil from the old compressor, and measure the amount. You then drain the new compressor, and replace the same amount of oil as came from the old compressor. Preferably use new fresh oil, and not the stuff you drained from the new compressor. Depending on what else gets replaced/flushed, then the amount going back into the system gets adjusted accordingly.

This is ok Dave except that the system loses oil over time. My fridge engineer pal blew out my system with nitrogen at first then a squirt of 134a and not a drop of oil came back out. He was certain this would be sufficient and was adamant that the oil level supplied with the compressor would be fine with any that was left in the system. Good luck finding the correct receiver/filter/drier, we had quite a job but did find one that was shorter but my pal was not put off by this. I can't remember whether it was the one he got or the eBay one I got but one fitted and one didn't.

My AC has been running fine since so all is good.

 

[Dave]

It will only lose oil through a leak, or if parts are replaced. The oil fill in a compressor is never the right qty as they dont know how much the system holds on the vehicle. This varies, not least with something that has rear air.

Blowing nitrogen through wont push out any oil, and it will take a lot of refrigerant to do so also.

Too much oil will stop the ac cooling, and can slug the compressor. Car ac and fridges are different animals.

 

[StarCruiser]

Totally agree Dave. This guy works on everything from a restaurant cold room through vehicle AC, refrigerated vehicles, water chillers, everything that is refrigeration and has done for over 30 years. His take on it was that it was better to have too much oil within reason than not enough. It was not critical to have the exact amount. We left the condenser to drain in various angles and got little to nothing out and separated and drained the pipes where possible, it was the evaporator he blew out and even he said it was unlikely to shift much. Of course my compressor had seized through lack of oil and refrigerant from leakage, mostly through the shaft seal though we changed all the O rings to be on the safe side. Oil plugging is a possibility but is usually down to having low points in pipework (flexi pipes hanging low can do it) that can gather oil and refrigerant if the right conditions exist. This is most unlikely on a well designed system such as in a vehicle (like the cruisers).

 

[frank rabbets]

That's the trouble with the car a/c system. It's not possible to "check" the oil level. I THOUGHT it was done when these auto machines regas the system, so did their operators. I learned the hard way by replacing parts, losing oil, and seizing my compressor on regassing. The machines can add clean oil if told to do so but cannot check if there is the correct amount of oil is in the system. So when I had a slight leak last year we put 2 ounces in as a guess.

 

[StarCruiser]

Again, too much oil UP TO A POINT is better than too little though it is only really possible to know the exact amount from new which is a luxury we don't have. They will run on remarkably little oil though (see statement above…). Mine clearly was low on oil for a lon time before it failed, though of course it led to failure.

 

[clivehorridge]

My A/C is behaving a bit odd lately. It works well for the first 1/2 hr, then it fades off cold to regular ambient temp.

It's probably low on fluid (again) but there's nobody here who knows what to do... not properly. They all have a go... though.

The o rings on the bulkhead connections may be the culprit.