AC help, please!

Dariusz Salomon said:

Capacities below.

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Dang you the man! So I assume pag150 is fine even though the compressor says pag 46?

I will replace orifice and see if I need to flush or replace compressor… I doubt it will be damaged because it simply blew out the hose due to heat and age, shut off immediately.

TCBRacer77 said:

I’ve seen different switches that “match” my year and model from oreily’s but they have different psi ranges…

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Here's the spec (attached) on the switch on the back of the compressor, from the 1998 manual.

You might look to RockAuto for the selection of switches and the specifications for each.

Dariusz Salomon said:

If you add "too much oil"it just gonna cool less-shouldn't be the cause of failure.

And make sure you add right amount of refrigerant and oil-tho I added more and it is still ok to this day. AC can be a right pain in the back side.

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Augmenting @Dariusz Salomon's comments:

Too much oil has a similar effect as too much refrigerant w.r.t. the high-side pressure; both take up space in the system, particularly on the high-pressure side where the refrigerant is mostly liquid (after it's condensed), and too much of both (liquid refrigerant and oil) "stuffed" into the high-pressure side of the system (i.e., between the compressor and orifice tube) can cause atypically-high high-side pressures. Ask me how I know.

So to whomever reads this, @Dariusz Salomon's comments are spot-on; add the correct amount of both.

TCBRacer77 said:

So I assume pag150 is fine even though the compressor says pag 46?

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It's not hard to find mixed messages on this. Attached are two documents, one from GM that says to use PAG46 in all R134a compressors (except R4 and A6), and another from TCC that says to use PAG150 in an HT6.

Sure, you might have used PAG46 had you known better at the time, but at this stage of the game I wouldn't go ape trying to replace it. That's my $0.02. I don't service AC systems professionally, but I've serviced a few and done some homework too.

1998_K1500_Sub said:

It's not hard to find mixed messages on this. Attached are two documents, one from GM that says to use PAG46 in all R134a compressors (except R4 and A6), and another from TCC that says to use PAG150 in an HT6.

Sure, you might have used PAG46 had you known better at the time, but at this stage of the game I wouldn't go ape trying to replace it. That's my $0.02. I don't service AC systems professionally, but I've serviced a few and done some homework too.

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Thx 98K1500-so are yours. To be safe-I'd find the ac garage-pump out everything with the machine,then pump in cirrect amounts-Sone of the oil will stay in the system(you'd have to flush it to get it out) but if machine shows healthy pressure in hi/lo sides you safe. And what I always say-add dye(pag150 with dye)-if you ever have another leak,you'll find it easily.

Dariusz Salomon said:

To be safe-I'd find the ac garage-pump out everything with the machine,then pump in cirrect amounts-Sone of the oil will stay in the system(you'd have to flush it to get it out) but if machine shows healthy pressure in hi/lo sides you safe. And what I always say-add dye(pag150 with dye)-if you ever have another leak,you'll find it easily.

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At least in my experience with the local GM dealer, the AC service equipment they use removes the refrigerant and, if some of the oil gets pulled along with the refrigerant, it will be removed too. Remember: The oil and liquid refrigerant are miscible, so oil will move readily with the refrigerant if the refrigerant is in a liquid state; if the refrigerant is in a vapor state, the oil may get blown along as the vapor moves through the system (this is how oil moves from the evaporator to the receiver / dryer). The local GM dealer's service tech told me they'll backfill with an ounce of oil after they've performed a controlled discharge / recharge of an AC system, i.e., using their service equipment.

Contrast the above with an uncontrolled discharge. If you break a hose (which you've done), the refrigerant blows out fast and carries a lot of oil with it. Too, since yours broke on the high-pressure side, you likely lost quite a bit of oil. As such, your oil balance is suspect. There are guidelines for re-establishing oil balance in this (uncontrolled blowdown) situation. The professional shop should have some idea what to do. I have a document which discusses this situation, somewhere, and if I find it I'll post it here.

1998_K1500_Sub said:

Contrast the above with an uncontrolled discharge. If you break a hose (which you've done), the refrigerant blows out fast and carries a lot of oil with it. There are guidelines for re-establishing oil balance in this (uncontrolled blowdown) situation. The professional shop should have some idea what to do. I have a document which discusses this situation, somewhere, and if I find it I'll post it here.

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Here's the information from the 1998 GM Service Manual regarding the uncontrollled discharge situation and their recommendation for oil re-balancing.

Others here may have their own advice.

So if I am reading this right, I need to measure how much oil is in compressor, replace with recommended amount listed in that document, and also add the recommended amount of oil to dryer… nothing else right?

TCBRacer77 said:

So if I am reading this right, I need to measure how much oil is in compressor, replace with recommended amount listed in that document, and also add the recommended amount of oil to dryer… nothing else right?

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Remind me: What parts do you intend to replace?
- Receiver / dryer?
- High-pressure hose from compressor to condenser?

1998_K1500_Sub said:

Remind me: What parts do you intend to replace?
- Receiver / dryer?
- High-pressure hose from compressor to condenser?

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Correct Just the hose and dryer and orifice