A/C questions

[89GMCSuburban]

Bingo, also, the oil becomes a sludge and likes to sieze every moving part of your AC system. Thankfully, GM used orifice tubes on these guys instead of a TXV (expansion valve), so buy the flush kit, a new compressor, accumulator and orifice tube and call it a day.

 

[cbbr]

Bingo, also, the oil becomes a sludge and likes to sieze every moving part of your AC system. Thankfully, GM used orifice tubes on these guys instead of a TXV (expansion valve), so buy the flush kit, a new compressor, accumulator and orifice tube and call it a day.

I'll add that now is a great time to convert to 134 once everything is flushed/drawn down.

 

[Justin Fleming]

I will have someone flush the system out after I put all new seals in. I will also be putting 134a back into the system. I will put a new dryer in and a new blue O piece. I am courious about the pump? The pump works fine and the air was rather cold when I had everything hooked up. So I am uncertain that I would replace that.

Any other comments are appreciated.


thanks

Justin

 

[cbbr]

If you had metal shavings in the orifice tube filter, its just a matter of time. It would be a good idea to do it all at once because when the compressor goes out, you have to replace the accumulator/orifice tube/ freon and have it flushed/drawn down again.

 

[opfor2]

I will have someone flush the system out after I put all new seals in.

No!!!! Flush the system (evaporator & condensor) BEFORE you replace any seals or o-rings. You can use a/c flush, paint thinner, or lacquer thinner. Flush the system until the flush fluid is clear and then flush again. Pump a lot of compressed air through the system to remove all dirt and flushing fluid. Allow the system to remain open for approx one hour so all the fluid can evaporate. Once this is done, know you can put the system back together using new o-rings and seals. Don’t forget to use Nylog on the o-rings and seals. And remember, you don’t flush the compressor, accumulator, dryer, or mufflers if your system has them. Most importantly don’t forget to pull a hard and long vacuum on the system of at least 29 Hg’s.

Good luck

Dan..

 

[Robert D]

If I were to replace the hoses, accumulator, condenser, compressor, what else would be necessary on these trucks? On the Porsche the A/C was simple enough with just replacing the compressor, dryer, lines. I do not yet own a Haynes manual, but is there directions within the Haynes for A/C rebuilds?

 

[opfor2]

Replace the orifice tube, but get a Ford Blue, not the OEM GM white "O" tube. And say away from the crappy "Smart" VoV's they suck.

Dan..

 

[89GMCSuburban]

Evaporator is the only thing you left out. That would replace every major piece in the AC. I wouldn't spend that much money on it though, man. What if it's a bad $8 low pressure sensor and you pitch almost $1,000 at the ac and it STILL doesn't work?

 

[Robert D]

Well the PO said he took the truck to a shop a few years ago and they quoted 2k for the repairs. He took it an in-law and was quoted 1500. They told him the hoses were bad among other things...he isn't very mechanically inclined and seems to have had most work done by shops. On the P-Car to test the A/C compressor clutch (it was an e-mag) all one had to do was hook a power source to the compressor and see if it engaged. Is the compressor on this truck the same situation? Is there a benefit to swapping entire compressor/clutch vs. clutch alone (aside from cost)? I'm going to most likely convert to 134a, and I've done this in 2 944s without flushing the system completely of r12. They both worked for over 2yrs before any further problems.


EDIT: When I mean not flushing completely, I mean I didn't VAC the system. I drained the r12 and filled with 134a.

 

[89GMCSuburban]

Best way, pull the plug on the low pressure switch (on the accumulator) and put a paper clip between the terminals of the plug. If the clutch comes on (with the AC on on the dash) you have power to it. That tests more than just the compressor clutch, so it's the better way to do it.

$1,500 was probably for a R134 conversion, and you have to remember, that includes labor...lots of it.

 

[Robert D]

I will try that Wednesday evening when working on the truck.