AC Compressor Issues (1 Viewer)

[CharlestonG8R]

2 years ago, I had my entire AC system replaced. I just wheeled the truck at GSMTR (pardon the mud, please) but it never got hung up on any obstacles, so I don't think anything was damaged... Still, I understand compressors are known to go bad. The compressor clutch sounds pretty bad when it engages and it is engaging/disengaging pretty rapidly (it doesn't normally operate like this).

This is what it sounds/looks like:



I had read other threads where the rapid clutch engagement was due to low coolant... I believed that might be my issue, but here is what the pressure gauge was reading when I attempted to fill the system:



Any ideas?

 

[1973Guppie]

guessing bad bearing in the AC clutch.....

 

[CharlestonG8R]

guessing bad bearing in the AC clutch.....

My thoughts as well, but would that cause the intermittent clutch engagement? Is the system trying to protect itself?

 

[1973Guppie]

My thoughts as well, but would that cause the intermittent clutch engagement? Is the system trying to protect itself?

I really am not sure? I am guessing if the clutch is seeing enough resistance from a bad bearing it might lock up? either way it sounds like at a minimum the clutch assembly should be replaced. It howling like that is not normal. If you still have problems with it engaging once replaced I would look at the electronics and switching mechanisms as culprits. From my understand the clutches go out more often than the actual compressors. But my AC knowledge is limited. Hopefully someone smarter than me will post up! Noah

 

[1973Guppie]

I really am not sure? I am guessing if the clutch is seeing enough resistance from a bad bearing it might lock up? either way it sounds like at a minimum the clutch assembly should be replaced. It howling like that is not normal. If you still have problems with it engaging once replaced I would look at the electronics and switching mechanisms as culprits. From my understand the clutches go out more often than the actual compressors. But my AC knowledge is limited. Hopefully someone smarter than me will post up! Noah

also, to confirm the bad bearing it is easy enough to remove the clutch assembly and spin it by hand, then you can confirm it is a rough bearing....

 

[AMX390]

Being low on refrigerant can cause short cycling, not to mention struggling sounds. Check your sight glass when it is cycled on.

Ewwwww! Just watched your videos, sounds like clutch bearings to me and the gauge does not seem to go low enough to cycle off. I'll have to think about this one a bit more. Does not sound good.

 

[Hinterland]

I had issues with mine turning off under heavy load when pulling hills. Turns out it just had too much pressure. We released a bit down to the middle of the green section of the gauge and its worked awesome ever since. Maybe try that first before replacing expensive parts.

 

[inkpot]

If you have ben in a lot of mud then take a pressure washer to the front end/grill/radiator to clean out everything first.

 

[1972FJ55]

Has anything been done to the A/C system since it was replaced? I'd really want to see what the high-side pressure is to be able to diagnose.
Normally, if the pulley bearing is going bad, it will make noise constantly and I can't tell from the video if the pulley is noisy or it's just the sound of the engine. If the compressor cycles on and off rapidly, it can overheat the bearing and take it out, but the bearing is just the result of something else being wrong.

 

[CharlestonG8R]

Okay, so based on almost everyone's feedback ( @1973Guppie I still need to see if the clutch spins free), I hosed down the engine compartment and idling with the AC clutch disengaged sounds much better. I also checked the sight glass and I see nothing but green (engaged or disengaged), so that's good I think... If anything, I have too much pressure in the system as @Hinterland suggested (did yours cycle rapidly when you had this condition?).

@1972FJ55 it's not constant noise in there, it's really only noisy when the compressor kicks on. To check the high side pressure, I assume I will need one of those manifold type gauges with 3 hoses.

The system is holding pressure, so I don't suspect a leak. My thoughts are that either the compressor is going bad, causing too much resistance, and not staying on (is there a sensor that controls this?) or there is a low freon sensor somewhere that tells the compressor not to stay on (is this a thing?). Those are my guesses at this time...

BTW, after I washed the engine, I threw a P0306 code for a few minutes but it went away. I cleared the code. Is this normal?

 

[1972FJ55]

Yes, you'll need manifold gauges to be able to read the high side. Since the noise is only present when the compressor is engaged, I'd guess it's either an overcharged system, the compressor is failing or there's an obstruction somewhere causing excessive pressure and then the pressure switch shuts the compressor off. The switch is a trinary switch, so it controls both high and low pressure and is located on the small diameter aluminum line by the battery box.

 

[CharlestonG8R]

Well, just to put this thread to bed... Turns out that it was an overcharged system AND a noisy compressor. I'm not sure if the two are related... Anyhow, I figured I should also share my experience with the Harbor Freight A/C Manifold Gauge Set. I shouldn't have been so trusting with this thing. I figured they probably did some sort of leak check on it at the factory, but that just couldn't be possible. The thing looked like a fountain when I hooked it up and opened the valves. It leaked all over and I have green dye all through my engine compartment. The high pressure attach valve fell apart when I turned the knob to disengage the pin. I'm sure others have had good experiences or else they wouldn't sell so many of them. Anyhow, some teflon tape and a screwdriver fixed the manifold for now... And just the right amount of R134a leaked out to get the thing working again. Sincere apologies to the ozone layer, I wasn't intending to be irresponsible.