Automotive Air Conditioning Information Forum

Working on my "new to me" '99 Caddy Deville Base, 67000 miles. The compressor, looks to be a parts house replacement, orange sticker, number 9366. Everything has been working / was working fine, then "Low Refrigerant" A/C off came up on dash. I put 4 oz dhot 110 degree cabin,ie in it and 12 ozs R134a, 16 oz total.. Pressures were Low 40, Hi 70 at 90 F temp. Cooled for about 10 minutes, 25 Degree temp drop, big shop fan in front of radiator/condensor, then I heard like a vibrating brrrrrrr noise. Sounded like a pop off valve, but I don't think (at least I can't see it) this compressor has one. The hole looks to be plugged with the standard plug & snap ring. Checked pressure again, 30 low, 100 high, compressor not running, service A/C light on. Seemed the system was holding pressure, later pressures would equalize & hold at 100 PSI.
Checked for leaks (UV light & bubble test), slightly yellow around compressor manifold, no bubbles. I took the oil filter off to get a better look. Pretty tight space on the 4.6 NorthStar. Evacuated system, vacuum of 30 held for 1 hour, re gased, 12 oz thru hi side, engine off, then 10 oz thru low side compressor running (jumped hot wire to compressor clutch) . Pressure built to 30 low, 150 hi, 94 temp, then the BRRRRR again & gas coming out around compressor manifold. The 15 mm bolt appears tight, I can't budge it! I can see green/yellow around O rings.
Question 1: What would make this high side O ring blow out all of a sudden? Restriction somewhere? Or maybe the previous shop repair not done up to specs.
Looks like original accumulator /dryer, at least GM sticker is still on the top. No wrench marks on dryer fittings or on high side orifice tube. Car Fax report shows auto was serviced regularly at Caddy Dealer.
Question 2": Is the original OEM condenser a parrell flow?
I'm thinking I better change out to a bigger, parrell flow condenser, a new compressor, dryer, and orifice tube. i.e., one of the "Kits" from ACKits to make sure everything is done correctly...
I'm going to check orifice tube tomorrow. Here in HOT & HUMID Mississippi, would the self adjusting Orifice Tube be better?
Thoughts & advice please!

I took the Orifice tube out of the '99 Caddy Deville. Looks like the BLACK DEATH! Black soot completely stopped up OT, somewhat oily, not dry. OT appears to be white, but after washing has more of a yellow tint.
My thoughts the aftermarket AC compressor is toast! Opinions please?
I have a new Four Seasons HD6 compressor, condensor, Accumulator but I dread DIY installation in this 105 degree heat!
Guess I'll flush the evaporator & lines, install the new parts, vacuum down, and try again!
How do you Attach pictures?? Clicking on "Attachments", It says "File too large". It's only 338KB's

I see that you posted your issue on another thread. That confused me until I noticed that your original post went unanswered. You should have just posted a second time on your original thread, which would have moved your questions to the top of the forum list. Regardless, I'll try offering some thoughts to your original questions here.

Bear in mind that the rather complicated A/C system in your car most likely requires a specialized scan tool to diagnose it and re-set any trouble codes (typically B1347 or B1348) that might be embedded in the Heater and A/C Programmer located under the RH side of the instrument panel. Any A/C trouble codes will have to be cleared before the compressor will re-start, even if the system is repaired and recharged. Your Cadillac dealer should have the capability to do that. The VERY LOW REFRIGERANT-A/C COMPRESSOR OFF message on the Driver Information Center will be cleared at the same time.

You said, " I put 4 oz dhot 110 degree cabin,ie in it and 12 ozs R134a, 16 oz total.."

Sorry, but I don't know what that is. I hope it wasn't sealer, though, as introducing sealer into the A/C system will probably clog it up and cause more problems than you had originally. Sealer will also ruin an A/C shop's expensive equipment.

You said, " Pressures were Low 40, Hi 70 at 90 F temp. Cooled for about 10 minutes, 25 Degree temp drop, big shop fan in front of radiator/condensor, then I heard like a vibrating brrrrrrr noise. Sounded like a pop off valve, but I don't think (at least I can't see it) this compressor has one. The hole looks to be plugged with the standard plug & snap ring. Checked pressure again, 30 low, 100 high, compressor not running, service A/C light on. Seemed the system was holding pressure, later pressures would equalize & hold at 100 PSI."

I suggest doing the simple procedures first: Recover whatever refrigerant remains in the system, evacuate, and recharge with the exact weight the specs call for, then measure the pressures and vent temp IF you can get the compressor to run. If you're still getting very low pressures on the high side with the system running at 1,800 RPM, then the compressor has probably destroyed itself internally.

You asked, " Question 1: What would make this high side O ring blow out all of a sudden? Restriction somewhere? Or maybe the previous shop repair not done up to specs."

Extremely high pressure, a restriction, parts not fitting together correctly, or a faulty o-ring could cause it to blow out.

You asked, " Question 2": Is the original OEM condenser a parrell flow? I'm thinking I better change out to a bigger, parrell flow condenser, a new compressor, dryer, and orifice tube. i.e., one of the "Kits" from ACKits to make sure everything is done correctly... I'm going to check orifice tube tomorrow. Here in HOT & HUMID Mississippi, would the self adjusting Orifice Tube be better?"

I believe the original condenser in your car is the parallel flow type. You can check this easily by examining it. Parallel flow has many narrow tubes that run individually from one side to the other. The tube-and-fin type has a somewhat larger serpentine tube that zig-zags back and forth. Changing to a larger condenser (that might not fit anyway) isn't really necessary as the system was designed to be efficient from the factory, and a different condenser might also disrupt the system's sensitive dynamics. I'd recommend staying with all original-spec parts.

Okay, I posted before I saw your second post. If you have Black Death, the compressor is toast. The system will need to be flushed and components replaced.

Sorry about the confusion, Spell check is a curse sometimes.
I added 4 oz of dye.
On the Caddy NorthStar 4.6L, it is impossible to see, even with an endoscope & mirrors, the back of the AC Compressor. The oil filter and it's housing has to be removed from the engine block. This compressor (HD6) has no relief valve on the back. The hi pressure relief switch is on the hi side outlet line.
AFter evacuation and "attempting to recharge" 18 oz, by weight, is all the system will take (requires 32 oz) before the BRRRRRR sound from the compressor. I removed the Orifice tube which was clogged with black oily matter. Unable to post a picture, DUH, can't figure out how. Says attachment file too large, it's only 338 KB!
Installed new white vacuum tube, the CORRECT way, old one appeared to be in backwards, and it still blows on the back of compressor at 18 oz. Low Side at 50 psi, hi side at 125 psi, 93 temp. System does not lose ALL of it's R134a, static pressures 40 both sides.
Sniffer and bubble test shows no leaks (static, engine off). Holds 30 pounds of vacuum overnight. 2 stage, 5.5 CFM new pump.
Obviously the non-OEM compressor is faulty.
I just dread having to replace all this stuff as HOT as it is here now.
When I do overhaul, what about the "Self Adjusting Orifice Tube"?
More trouble than it's worth?
BTW, how do you insert images or post pictures?
Thanks for answering

Oh, oh...four ounces of UV dye is way too much. You need less than one-fourth of that amount next time, only about one-half ounce or so.

Flushing the evaporator and lines (if they don't have mufflers), then installing the new components sounds like a good plan. Even with a full charge, the new compressor might not run until you clear the trouble code(s), as I mentioned earlier. The old compressor is definitely shot and also probably leaking someplace.

I've never installed a variable OT, so I can't comment on that. It's hard to go wrong with the original-spec part, though, IMHO.

I'm fairly new to this forum and never tried posting pictures or other attachments. One of the moderators could surely help with that.

It's brutally hot here in South Carolina as well and certainly no fun working outdoors. Good luck with the project, stay hydrated, and let us know the final outcome.

The small 4 oz can of dye + R134a is mostly refrigerant.
Seems like the OL BLACK DEATH GETS a lot of the parts house compressors. The system probably wasn't rebuilt correctly. The accumulator looks original. ORT in backwards! OEM condensor, etc. All new parts & a good drawdown oughta fix it.
Clearing the B1347 & 1348 codes is another matter. Hold warm & off button, then push down on fan speed may clear them.
Thanks, will keep u updated.

rebranger wrote:The small 4 oz can of dye + R134a is mostly refrigerant.

Got it...good!

rebranger wrote:Seems like the OL BLACK DEATH GETS a lot of the parts house compressors. The system probably wasn't rebuilt correctly. The accumulator looks original. ORT in backwards! OEM condensor, etc. All new parts & a good drawdown oughta fix it.

Agree about the apparently incorrect rebuild. If someone put a compressor in it, he/she also should have changed the condenser, accumulator, and OT. Hopefully, you'll have it working again soon, especially now when you need it most during the hot summer.

rebranger wrote:Clearing the B1347 & 1348 codes is another matter. Hold warm & off button, then push down on fan speed may clear them.

It's certainly worth a try. If it works, you won't have to make an appointment at your local (expensive) Cadillac dealer to have them clear the codes.