Gain extra benefits by becoming a Supporting Member Click here find out how!

Classic Performance Products Classic Parts
American Auto Wire Classic Industries
Danchuk Catalog
Hellwig Products IncPerformance Rod & CustomJoin the Community today
Ecklers AutoMotiveNu-Relics Power Windows



Username Post: 2002 Yukon A/C rebuild        (Topic#357196)
gchemist 
Senior Chevytalk Moderator
Posts: 24934
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
07-11-19 06:46 PM - Post#2770496    

A friend is bringing a Tahoe for an A/C rebuild. It has rear a/c. Does anyone have short cuts to clean out the rear lines? Does the compressor come out easier through the top with the shroud removed? We are replacing the rear expansion valve too. No expenses spared to replace all major components. Info I found says to charge with 42oz and 11 oz PAG46. Is my info correct?

'83 Silverardo XST - ZZ4 powered
'95 Jimmy SLT (Bought @131,814)
'96 GMC Jimmy LS Ret. @236651 miles


 
rockfangd 
"6th Year" Gold Supporting Member
Posts: 2753
rockfangd
Age: 33
Loc: Utica ny
Reg: 04-13-10
07-11-19 07:45 PM - Post#2770502    
    In response to gchemist

Hello.
Each component gets a share of the oil.
IS it currently not working?
if it is a 4.8, 5.3, or 6.0 the compressor comes out of the bottom. Located passenger side lower.
PAg oil is pag 46
Orifice tube is in the line to the evaporator.
Do not put too much oil in the compressor as it will overwork the clutch, especially being it is lowest in the system.
I make it a habit to manually turn the compressor a few times to circulate the oil before I start the engine.
I also burnish the clutch by cycling it on and off about 10 times in a row.
Closely inspect the condenser, any questionable replace it.
As for the rear
Inspect the lines.
Inspect the evaporator, make sure the box is clean and drains.
Generally unless the whole system is contaminated or rust is a issue The rear is usually not much of a issue.
Best of luck to you

Old School GM fan FOREVER


Edited by rockfangd on 07-11-19 07:53 PM. Reason for edit: No reason given.

 
gchemist 
Senior Chevytalk Moderator
Posts: 24934
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
07-12-19 10:58 AM - Post#2770533    
    In response to rockfangd

rockfang,
It's a 5.3.dual a/c. I found a very loose low pressure valve stem. It was replaced with a new one. The orifice tube shows no signs of metal debri. It's old. I put it on vac for an hour. It held for more than 30 min. However it won't take more than a 1/2 can. The compressor makes a lot of noise too. Wow, how did GM put the low and high pressure ports on the same line? Only the orifice tube separates them. Does it charge up the same way? It had no pressure or R134 left it when I started.



Attachment: tube.jpg (83.24 KB) 5 View(s)




'83 Silverardo XST - ZZ4 powered
'95 Jimmy SLT (Bought @131,814)
'96 GMC Jimmy LS Ret. @236651 miles


 
rockfangd 
"6th Year" Gold Supporting Member
Posts: 2753
rockfangd
Age: 33
Loc: Utica ny
Reg: 04-13-10
07-12-19 06:41 PM - Post#2770564    
    In response to gchemist

Ok so you pulled a vacuum for 1 hour,
let sit for 30 minutes, gauges held,
then charged only half a can.
The compressor kicks in on its own?
Are your valves completely open(I know that sounds stupid but believe me it happens)
What brand gauges are you using?
Was the compressor replaced? Those compressors were really common to failure due to the design of the system, too much oil gets down into the compressor and it bogs the compressor on startup, eventually it locks up or fails

Old School GM fan FOREVER


Edited by rockfangd on 07-12-19 06:44 PM. Reason for edit: No reason given.

 
gchemist 
Senior Chevytalk Moderator
Posts: 24934
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
07-13-19 05:43 AM - Post#2770582    
    In response to rockfangd

After failing to charge, I went ahead and did a full replacement. The compressor made too much noise anyway. We replaced the condenser, compressor, orifice tube, drier, gaskets, o-rings, and rear expansion valve. We lucked out on the rear valve. The housing designed changed. The valve is located at the back rear part of it. We used a sharp knife and cut an access hole. Using wrenches we removed the valve. A new o ring was used to install the new valve. We even pushed the copper end back into the factory glue on the evaporator line. The valve was clogged up with junk.
The right headlight and turn signal were removed. The plastic housing for lights was removed too. With it removed, the condenser slid out to the right.
The drier came off easy by taking it off with its bracket attached. The fender wheel liner pulled back to reach compressor bolts. The tensioner and lower compressor bolts were reached through the bottom. The compressor came out over the frame rail and wedged below the heater core hoses. Per instructions we drained all compressor oil. It had 8 oz in it. The kit bottle came in 8 oz. Using a funnel, I poured it into the evaporator. The only other place to add oil was the drier. I didn't think that would have been a good place to add oil. I did turn the compressor manually several turns to lube it.
The system pulled to 24-26 hg fairly quick. I kept it under vacuum for an hour per instructions. Waited 15 min only due to daylight running out. We charged it up. Similarly, I was stunned that the compressor wouldn't kick on. I bypassed the low pressure switch to test compressor activation. It turned on. After a few tries I checked for charging videos. It seems since the high and low pressure sides are on the same line, charging is different. On older systems, the can should not be turned upside down. Doing so sends liquid to the compressor. On this single line port system, you can add cans by inverting them. I had the gauges too high to feed an empty system. It took 3 full cans and a partial. It should be close enough to 42 oz. It's cooling front and rear. My friend will bring it back in a day or two to check pressure readings. He says the compressor is quite and cycling. So, I think we did it. We hope the Korean made pump can hold up to Texas use.

'83 Silverardo XST - ZZ4 powered
'95 Jimmy SLT (Bought @131,814)
'96 GMC Jimmy LS Ret. @236651 miles


Edited by gchemist on 07-13-19 03:32 PM. Reason for edit: No reason given.

 
rockfangd 
"6th Year" Gold Supporting Member
Posts: 2753
rockfangd
Age: 33
Loc: Utica ny
Reg: 04-13-10
07-13-19 08:01 AM - Post#2770593    
    In response to gchemist

Excellent.

Old School GM fan FOREVER


 
gchemist 
Senior Chevytalk Moderator
Posts: 24934
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
07-15-19 04:21 AM - Post#2770722    
    In response to rockfangd

My friend woke up the next morning to install the grill and rear paneling back on. He then drove from Austin to San Antonio with his kids. They were all happy. He says it's iceberg cold! He was so happy he even washed and waxed it. It was almost parked a year without A/C. He saw a few pics I posted and asked me to do it. I learned a lot of shortcuts for a dual A/C system. Hope my info helps someone too.

'83 Silverardo XST - ZZ4 powered
'95 Jimmy SLT (Bought @131,814)
'96 GMC Jimmy LS Ret. @236651 miles


 
gchemist 
Senior Chevytalk Moderator
Posts: 24934
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
07-17-19 06:05 AM - Post#2770892    
    In response to gchemist

So far so good. Now, plans are to ditch the clutch fan and install electric fans. Either LS1 or +05 truck fans. Since the ECM can handle control with programming, that's the option I'm recommending.

Has anyone up graded to electric fans? So far, I've found two different places that sell a harness and ECM programming. Fans can be purchased separately or as a combo.

'83 Silverardo XST - ZZ4 powered
'95 Jimmy SLT (Bought @131,814)
'96 GMC Jimmy LS Ret. @236651 miles


 
jktucker92 
Silver Supporting Member
Posts: 309
jktucker92
Loc: West Richland, WA
Reg: 02-05-17
07-17-19 09:16 AM - Post#2770905    
    In response to gchemist

Upgrading to the '05+ setup is supposed to be pretty straightforward. You just need the relay box and wiring from a donor truck, along with the fans. From what I've seen, everything snaps together, and you just have to add a pin to your ECM connector. I haven't done it yet, but a friend did it and advised me to do the same.



 
gchemist 
Senior Chevytalk Moderator
Posts: 24934
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
07-17-19 09:55 AM - Post#2770912    
    In response to jktucker92

jktucker92,
Thanks for the info. Do the 05+ trucks use a bigger radiator? Seems that to use 05+ fans that bolt on, the radiator must be a bigger size. I'll have go look for 05+ truck to review the relay box.

'83 Silverardo XST - ZZ4 powered
'95 Jimmy SLT (Bought @131,814)
'96 GMC Jimmy LS Ret. @236651 miles


 
jktucker92 
Silver Supporting Member
Posts: 309
jktucker92
Loc: West Richland, WA
Reg: 02-05-17
07-18-19 05:01 PM - Post#2771009    
    In response to gchemist

I thought it was the same radiator, and the fans used the fan shroud mount points. Need to look at one in a junkyard to confirm.



 
gchemist 
Senior Chevytalk Moderator
Posts: 24934
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
07-29-19 04:27 AM - Post#2771878    
    In response to jktucker92

Another fellow Vet had the same problem on his 2002 Tahoe. Using pics and info from me he was able to make repairs. He had it evacuated and recharged at a local shop. He made a bigger cut to access the lower nut. He used Eternabond(EPDM) tape to seal his back up.

Attachment: IMG_2471__2_.jpg (31.24 KB) 4 View(s)


2002 Tahoe with rear A/C expansion valve.


'83 Silverardo XST - ZZ4 powered
'95 Jimmy SLT (Bought @131,814)
'96 GMC Jimmy LS Ret. @236651 miles


 
Icon Legend Permissions Topic Options
Report Post

Quote Post

Quick Reply

Print Topic

Email Topic

337 Views
FusionBB
FusionBB™ Version 2.1
©2003-2006 InteractivePHP, Inc.
Execution time: 0.083 seconds.   Total Queries: 19   Zlib Compression is on.
All times are (GMT -0800) Pacific. Current time is 09:20 AM
Top