GM Truck Club Forum banner
1 - 20 of 24 Posts

·
Registered
Joined
·
582 Posts
Discussion Starter · #1 ·
Just an FYI to help other folks

Have not worked on my broken ac in a long time. Last time mechanic charged it, worked, later failed and he said compressor shot.

Therefore, took a while to get all equipment and understand how to use. Not explaining how to test in this writing.

1st - Checked vacumn
Vacumn. 26 mm Hg - Pulled down quickly for an economy vacumn.
Held vacumn for 30 minutes.
No leaks

Charging
Charged and took about a half can.

Issues
Low and high side pressures not in line with specs (off alot) relative to temperature.
Noticed oil all over compressor and clutch not working right.
Already replaced clutch once long time ago.


Going to replace compressor, orifice, and condensor with oem rather than troubleshoot at this point due to age and my observations.

Purchased yellow jacket parts mainly due to quality and safety. Worked and sealed perfectly. You can get all these material much cheaper elsewhere. It is just my choice.

Yellow Jacket

Series 41 Brass Manifold ~ $100
High Side Coupler - 41337~ $50
Low Side Coupler - 41338 ~ $50
Quick Coupler for Charging -19165~ $10

Sure Bilt

R-134A Can Tap Dispensor - Self-sealing non piercing type Autozone (Trying to find a yellow jacket one)

Vacumn Pump Robinair 15500 = 5CFM, 2 stage, 35 um, 1/2 hp, has all adapters ~ $210
Once it pulls down quiet as a bug, This is more of an economy pump, not everyday use but not cheap..

Had to change oil first time pulling vacumn after 10 minutes since oil turned slight yellow. Was fine after that. Junk in system.

Will keep you posted on how it goes. Need to order parts which takes time and availability, and shipping is not the best. Took almost a month to get vacumn pump. Lost the first one to never never land. Customer service is good, however. Some stuff you can't control nowadays.
 

·
Registered
2001 Suburban 5.3L, 310k miles
Joined
·
1,845 Posts
My 2001 still has all original ac system at 303k miles.
I change orifice tube and put an acid neutralizer every 100k.
Don't run ac with low refrigerant charge.
When low on charge, fix leak sources immediately. My only leak sources were the low and high side Schrader valves and drier/ accumulator mounted low pressure switch.
I bought a spare ac compressor and drier/accumulator when it was at 100k anticipating it will not last over 100k miles.
Original compressor is still working !


Good luck @wdc1 .
Don't use vacuum for leak test.
Use positive pressure to 200 psi and Big Blue micro leak detector for leak testing.
 

·
Registered
Joined
·
582 Posts
Discussion Starter · #4 ·
My 2001 still has all original ac system at 303k miles.
I change orifice tube and put an acid neutralizer every 100k.
Don't run ac with low refrigerant charge.
When low on charge, fix leak sources immediately. My only leak sources were the low and high side Schrader valves and drier/ accumulator mounted low pressure switch.
I bought a spare ac compressor and drier/accumulator when it was at 100k anticipating it will not last over 100k miles.
Original compressor is still working !


Good luck @wdc1 .
Don't use vacuum for leak test.
Use positive pressure to 200 psi and Big Blue micro leak detector for leak testing.
Thank you. It took a while to make sure I have the right equipment, use it and test but good now but saves money in long run.

You use a nitrogen (100 %, no water, tank) correct? Where to get it and can system take 200 psi? I see some small nitrogen cylinders but just need regulator or maybe they rent.
 

·
Registered
Joined
·
582 Posts
Discussion Starter · #6 ·
Removed the accumulator (easy) and compressor (harder) and orifice.
Ordered parts(3) and arrived today. All OEM. Rock Auto

Flushing question. Before compressor and accumulator and orifice install.

(Have compressor so can pour in solvent and push in 60 psi easily. (Compressor has water filter.)
Thinking of using IPA (99%) Technical Grade for cleaning.
  • Flush from fire wall to rear ac OK. Only an evaporator there.
  • Flush disconnected lines OK.
  • Don’t flush parallel-flow condenser??. Apparently you can’t and they suggest to buy new one. Not sure I have one.
  • Don’t see an expansion valve and not sure where it is. Someone said said can’t flush that.
Just want to make sure what I can flush. Thanks.
 

·
Registered
2001 Suburban 5.3L, 310k miles
Joined
·
1,845 Posts
How did the compressor fail?
Did you see a lot of metal debris on the orifice tube screen?
 

·
Registered
Joined
·
582 Posts
Discussion Starter · #8 ·
A long time ago I replaced the clutch(failed) and it was a pain and cost alot so if it failed again I said it is better to buy a new compressor with clutch cost wise. Also in taking off the clutch damaged something on compressor chipped off that I can't remember but went ahead and used it as is. Once I pull off clutch which is like stuck on wil find what I did in the past. Trying to so clean out. No metal I can see in orific but did not look good. Very dirty. Cleaned it with brake cleaner and saw nothing but could of been flushed out. There appears to be this green junk in some lines maybe leak test the shop put in.
 

·
Registered
2001 Suburban 5.3L, 310k miles
Joined
·
1,845 Posts
That's good then if the orifice has no metallic debris from compressor mechanical failure.
No need to flush.
Replace the compressor, drier, front orifice and rear expansion valve, pressurize with nitrogen to 200 psi and do a leak down test.
 

·
Registered
Joined
·
582 Posts
Discussion Starter · #10 ·
All my parts (3 as mentioned above) are in except the rear expansion valve but installing what I have. I can see why the orifice is a good test for how clean the system is. Saw some on You tube with metal and debris and totally clogged, Mine I was able to clean off easily.
That said removed the back panel. Lots of screws and wire disconnects but just takes some time. Heater core and condensor look brand new. No debris, liquid, seepage observed. Will blow out dust with my compressor. My suburabn has good room to remove expansion valve but I looked at other suburbans that are really tucked in there. Will keep you posted. Thanks. I am a night owl on working. Like the peace and quiet, helps me focus, hence late email.
 

·
Registered
2001 Suburban 5.3L, 310k miles
Joined
·
1,845 Posts
Actually, if the compressor did not lock up and fail internally, the system shd be clean.

My original HVAC has 302k miles now and the expansion valve still works and cools the rear cabin.

Just clean the evaporator coil and the fan it shd be good. Do not forget to clean the evaporator condensate pan drain. Mine got clogged, it overflowed and soaked the rear carpet wet. It smelled real bad. I had to lift the carpet up to dry the carpet pad for a few days.
 

·
Registered
Joined
·
582 Posts
Discussion Starter · #13 ·
All back together and doubled checked all for tightness and electrical connections.

Using yellow jacket gauge.

Connections were low side (blue hose) connected to low side coupler on car, high side (red hose) connected to high side coupler on car, vacumn (hose yellow) hooked to vacumn pump. Both knobs open on gauges on and both high and low side couplers open.

Pulled down 28 mm hg easily.

Turned off low and high side at gauges,

Let sit for 30 minutes. Held fine.

Purged yellow hose with R134.

Turned on car and AC/

Turned on low side at gauge. and charged 3/4 small can. Both high and low side at 60 psi and stopped.

Clutch not kicking in. I can turn by hand with car off but won't click on when ac on and charging. Not sure why.
 

·
Registered
Joined
·
582 Posts
Discussion Starter · #14 ·
I did not disconnect battery in all this since it was used during the week and the truck does not like battery disconnect.

Takes a while to relearn. I had to clean out a lot of grease, dirt, etc.with degreaser and water.

When I thought of that I said check the fuse. Yup, 10 amp ac comp was blown. Just to test since I had no 10 Amp( all the rest I had!!) so put a 7.5 amp in there. Clutch clicks on and off now. Not fully charged of course but will do that soon.
 

·
Registered
Joined
·
582 Posts
Discussion Starter · #15 ·
All put back together except cover in rear ac. Also have to find picture on how clip connects to rear expansion valve.
Will also monitor for leaks and how it works over time. Fall coming but there will be hot days for sure.

Have not measured how cold but will but feels comfortable front and rear but not very cold.

Your thoughts on replacing condensor which also includes trans cooler for the age of vehicle?

Low side very cold and high side hot or very warm as expected,
 

·
Registered
Joined
·
582 Posts
Discussion Starter · #16 ·
All put back together except cover in rear ac. Also have to find picture on how clip connects to rear expansion valve.
Will also monitor for leaks and how it works over time. Fall coming but there will be hot days for sure.

Have not measured how cold but will but feels comfortable front and rear but not very cold.

Your thoughts on replacing condensor which also includes trans cooler for the age of vehicle?

Low side very cold and high side hot or very warm as expected,
By the way once enough charge was in clutch kicked in an
d out nicely.
 

·
Registered
Joined
·
582 Posts
Discussion Starter · #17 ·
All back together and works fine. Hard the first time now much easier. Could be a little colder but may be due to front condenser but will hold off on that. Need to pay off all I bought. Used paypal no interest. Thanks for all your help.
 

·
Registered
2001 Suburban 5.3L, 310k miles
Joined
·
1,845 Posts
I had a marginal ac on my 2001 especially at idle when stopped during the summer. It cools very good at speed.
I had a clutch fan that will not fully engage when hot. Replaced that around 190k miles and it started cooling at idle.
 

·
Registered
Joined
·
582 Posts
Discussion Starter · #20 ·
Truck start (sitting overnight) clutch fan runs. Truck start clutch fan runs when ac runs.

Never stops. Hard to move fan and when try to spin goes a few inches.

Think the clutch fan is bad.

From my records changed thermostat , water pump, and coolant recovery cap at 127,000 2014 no clutch fan.

Therefore, never changed and now at 202000.
 
1 - 20 of 24 Posts
Top