93 6.5 A/C not working right

[slicer89]

I recently refilled my 93 A/C with 134a. (It had already been retrofitted from r12) and for whatever reason, when it runs... Sometimes it will squeel quite loudly from the AC compressor and other times it will take a while before it does.... And up here in Montana it would be nice to have it working in the summer - But I don't want to throw my belt, or burn it up.

I didn't over charge it, The gauge on the AC pro can I got said it was right around where it needed to be

Is the compressor going out, or did I do something wrong?

[DmaxMaverick]

It could be overcharged, regardless of what the "can" says. The gage with the can/kit is intended for original R134a systems, not specifically "converted" systems. The HI and LO sides need to be monitored to really know what the system is doing, and what it requires. Too much oil can also be a problem, as it displaces freon, doesn't compress, and doesn't evaporate.

First, determine what's squealing. Is it the belt, or clutch? If it's the belt, is it stalling, or squealing while it's turning, intermittent or continuous? The belt could be due for replacement, or it's not up to the needed quality. Any more "squeal" than an occasional chirp will likely condemn the belt, anyway.

If it's the clutch, it can be replaced (not a job for just anyone), but usually means a new pump.

[slicer89]

It could be overcharged, regardless of what the "can" says. The gage with the can/kit is intended for original R134a systems, not specifically "converted" systems. The HI and LO sides need to be monitored to really know what the system is doing, and what it requires. Too much oil can also be a problem, as it displaces freon, doesn't compress, and doesn't evaporate.

First, determine what's squealing. Is it the belt, or clutch? If it's the belt, is it stalling, or squealing while it's turning, intermittent or continuous? The belt could be due for replacement, or it's not up to the needed quality. Any more "squeal" than an occasional chirp will likely condemn the belt, anyway.

If it's the clutch, it can be replaced (not a job for just anyone), but usually means a new pump.

I see. I know someone who has some refrigerant gauges (Don't know the technical name) and will see if I can use them

It's the belt. It seems like as soon as the clutch engages, it starts to squeal. If it will help, I could make a video of what it's doing? It's hard to describe.

[DmaxMaverick]

I would start with a new (quality) belt. If the old belt is aged or glazed, it may not matter what you do, it will continue to slip.

You will need an R12 gage set or conversion adapters for the R134a set. The fittings are different, between R12 and R134a systems. The "range" markings on the R12 set won't correlate, either. You'll need someone experienced with converted systems to optimize your specific system. This is not a DIY thing, w/o experience. Bad (catastrophic) things can happen, the least of which is not having A/C.

[dsnyder]

A squealing AC can be a loose belt, high head pressure or even a compressor or compressor clutch going bad. Without gauges it is tough to say which.

First make sure the belt is reasonably new and tensioned enough.

Does the squealing happen when it is very hot outside or all the time? The harder the AC works, the harder it is to turn the compressor so if your belt is good and it squeals when it is quite hot out, that can be an overcharged system. Most systems have high pressure cut outs and Montana is relatively not that hot so I think the overcharge is doubtful.

A bad compressor clutch can also cause issues... as the clutch gets weak it slips.

When specifically does it squeal? After a fast run when you drop back to idle or when you first engage? The fast run drop back would be high head pressures, the first engage would be belt or compressor issues.