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Username Post: R4 R134 charge        (Topic#357223)
gchemist 
Senior Chevytalk Moderator
Posts: 24893
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
07-14-19 10:22 AM - Post#2770673    

After fixing a Tahoe dual A/C system on Friday, I decided to tackle BADBOW. It's been a while since I drove it with A/C. The pressure port valve stem was found loose. I should have known a leak was somewhere. The gauges indicated it had a partial charge. Having two partial cans available, I put them in. I kept adding until the low side came up above 40 PSI. For the current temp, 45-55 PSI would be ideal. The high side went up to 250-260 before a trinary switch would cycle the LS1 fans. Both partials cans were empty before low pressure reached 50. 40-45 will do for now. Pressure dropped really fast once fans were running. I watched fans and pressure cycle nicely. Afterwards, a nice ride in cold A/C was warranted for a car wash. I'll be driving to work all week. No rain expected this week. Temps will be close to 100.
The new ceramic tint works great too.

Attachment: R4compressor.jpg (123.79 KB) 7 View(s)


R134 charge


Attachment: pressure.jpg (92.54 KB) 6 View(s)


R134 pressures


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


 
100 CHEVY 
Dedicated Member
Posts: 6492
100 CHEVY
Loc: Helena,Missippi,U.S.A.
Reg: 12-09-04
07-14-19 10:35 AM - Post#2770676    
    In response to gchemist

Ain't it great to ride in a cool truck!
Just vacced and recharged my 68,C-10 last week.Still has a very slow leak somewhere,but will last the season.
Need to fix my 79,C-10 next.
Mike.

"You gonna leave it like that?
http://www.picturetrail.com/100chevy


 
gchemist 
Senior Chevytalk Moderator
Posts: 24893
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
07-16-19 04:05 AM - Post#2770801    
    In response to 100 CHEVY

Third running day. I have to turn it down to the second fan setting or it freezes me out. So far so good. Next, bypass the heater core for extra cooling. I'll go get a few clamps this week.

Grab a Elitech WJL-6000 on line. It's dirt cheap. I use it to find leaks in R134 systems. It's been good so far. Good batteries are important.

The compressor is at least 3-4 years old. My local shop does not rebuild them anymore. The shops says it's a bad compressor. I'll run it until it blows up. The last one blew up after a high RPM run. R4s don't make it past 5000 RPMs. So if I punch it WOT, I need to have A/C turned off. I'm going carry the bypass pulley, new belt, and some tools in case it locks up while driving around. A dash light will tell me if the belt gives out. The light turns on when the alternator stops charging.

An auxiliary front cooling fan is on the list for addition too.

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


Edited by gchemist on 07-16-19 04:06 AM. Reason for edit: No reason given.

 
gchemist 
Senior Chevytalk Moderator
Posts: 24893
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
07-16-19 04:35 AM - Post#2770804    
    In response to gchemist

Tech tip on how to close the radiator/condenser gap for better A/C and engine cooling.

http://www.gmtips.com/3rd-degree/dox/tips/c ool/ac-...

The front grill be off soon. I'm waiting on a vinyl bow tie wrap emblem. When I install the emblem, I'll add insulation to close the radiator/condenser gap.

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


Edited by gchemist on 07-16-19 04:36 AM. Reason for edit: No reason given.

 
gchemist 
Senior Chevytalk Moderator
Posts: 24893
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
07-16-19 06:11 AM - Post#2770813    
    In response to gchemist

If anyone is looking to order strips to close the radiator/condenser gap, look at these Vette options.
Vette radiator/condenser options.

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


 
gchemist 
Senior Chevytalk Moderator
Posts: 24893
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
07-18-19 06:54 PM - Post#2771020    
    In response to gchemist

The radiator and condenser gap is closed. Cooling and A/C will work better. The gap is well over 1.5". I'll watch engine temps and A/C temps. If this works good, then I'll hold off installing an auxiliary condenser cooling fan. A 12" stock bracket fan is ready if necessary. A 6' pipe rubber insulation hose was trimmed to fit. Don't use foam. Foam will melt under radiator heat. The rubber should hold up.

Attachment: IMG_1749.jpg (55.81 KB) 7 View(s)


Right radiator and condenser gap.


Attachment: IMG_1750.jpg (70.42 KB) 5 View(s)


Left radiator and condenser gap.


Attachment: IMG_1751.jpg (97.82 KB) 5 View(s)


Right side gap closed.


Attachment: IMG_1752.jpg (94.1 KB) 5 View(s)


Left side gap closed by wrapping pipe insulation around radiator corner.


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


 
gchemist 
Senior Chevytalk Moderator
Posts: 24893
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
08-11-19 12:15 PM - Post#2772966    
    In response to gchemist

Update:
The R4 is working well right now. I did catch it slipping the other day. So I checked the clutch gap. So far even in 90+ degree weather, cooling and A/C are working good with a dual fan LS1 set up. The fans are quieter since air is pulled through condenser and radiator. I had to fix my Nitro A/C system on Thur. It pulls to 40 degrees while driving. Hope BADBOW can do the same or better.

A new R4 replacement compressor is next. I bought a Sanden SD7HD with an R4 hose end plate. The hoses will bolt on. My only concern is one hose. The high pressure hose may be too short. The hoses are custom cut. My local shop even updated the drier. I'll be able to remove the lower "J" fitting. Instead, the hose will connect directly to the drier. I have all the parts minus an orifice tube. I won't have time to install it this week. Maybe next week. With planned updates it may take 2-3 days. Updates include: 100 amp relays (3), one for each fan, upgraded fuses, better wire routing and auxiliary fan install. All this plus the bypass valve.

The plus, a Sanden HD compressor can do 8000 RPMs. I'm afraid to go over 3000 RPMs right now. One hard pull to 5000+ RPMs blew up the last R4. The R4 is a real power hog. I can't wait to ditch it.

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


 
gchemist 
Senior Chevytalk Moderator
Posts: 24893
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
08-13-19 06:18 AM - Post#2773121    
    In response to gchemist

Accumulating parts for an R4 to SANDEN conversion. The Sanden can take a hit to 7000 RPMs. It can maintain 6000 RPMs continuously. It will be nice to hit WOT again and not worry about it blowing itself up.

Oil charge will probably match a 88-95 1500 truck. The compressor is on the same side. R134a levels will be based on pressure. I'm working on at least a minimum amount. An auxiliary fan will help cool the condenser faster.

More A/C info: https://www.chevytalk.org/fusionbb/showtopic.php?t...

My truck has a serpentine belt. So A/C specs are going to be close a '94 full size truck.


Attachment: drier.jpg (43.08 KB) 2 View(s)


Updated drier to remove the lower J connection.


Attachment: SANDEN4864.jpg (75.11 KB) 2 View(s)


SANDEN 4864 model. It has an R4 hose rear plate connection.


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


Edited by gchemist on 08-13-19 02:23 PM. Reason for edit: No reason given.

 
gchemist 
Senior Chevytalk Moderator
Posts: 24893
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
08-15-19 07:57 PM - Post#2773281    
    In response to gchemist

Prepping the condenser auxiliary fan. It will use a 100 amp relay for power supply. A trinary switch will control fan activation.

Attachment: gmfan.jpg (127.45 KB) 5 View(s)


GM pusher auxiliary condenser fan.


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


 
1983G20Van 
Super Senior Member
Posts: 3767

Loc: Bedford, Texas, USA
Reg: 11-13-02
08-25-19 09:17 PM - Post#2774044    
    In response to gchemist

  • gchemist Said:
Accumulating parts for an R4 to SANDEN conversion. The Sanden can take a hit to 7000 RPMs. It can maintain 6000 RPMs continuously. It will be nice to hit WOT again and not worry about it blowing itself up.

Oil charge will probably match a 88-95 1500 truck. The compressor is on the same side. R134a levels will be based on pressure. I'm working on at least a minimum amount. An auxiliary fan will help cool the condenser faster.

More A/C info: https://www.chevytalk.org/fusionbb/showtopic.php?t...

My truck has a serpentine belt. So A/C specs are going to be close a '94 full size truck.




There is a very easy way to fix your compressor problem. Add a TH400 kickdown switch to your accelerator pedal bracket. Hook one side of the switch to ground. Add a relay into the a/c clutch circuit using the normally closed contact. Power the relay from the supply wire to the clutch. At part throttle the a/c compressor stays engaged. When you go WOT the kickdpwn switch grounds the a/c relay cutting power to the compressor clutch. When you let off the throttle the a/c clutch re-engages. Even with the Sanden upgrade I would still cut the compressor off at WOT for all the power you can get. My old G-van had a factory switch that cut the compressor clutch power feed at WOT. the switch would deactivate just before the Q-Jet opened the secondaries and the 700r4 downshifted. The A6 blew ice cubes but was even more power hungry than the R4 in my opinion especially on the 305.

1983 G20 Van, 350 TPI, Ported 906 Vortecs, Edelbrock 3817 Base, ASM oversize runners. Reed Custom Roller cam, 700r4, 12 bolt with 3.08 gears, Doug Thorley Tri-Y headers, true duals


Edited by 1983G20Van on 08-25-19 09:22 PM. Reason for edit: No reason given.

 
gchemist 
Senior Chevytalk Moderator
Posts: 24893
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
08-26-19 04:30 AM - Post#2774049    
    In response to 1983G20Van

The R4 is definitely power hungry. Even at idle, 800 RPMs, it drops it down to almost 600 RPMs. Cruising at low speeds, I can tell the difference. Even fuel usage is huge. Adding a switch to the pedal should be easy. Thanks for the idea!!

The R4 definitely works. It will freeze the small cab fast. I still need to install a heater core bypass too.

Now on to go look for a switch.

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


 
corvesy 
"4th Year" Gold Supporting Member
Posts: 687
corvesy
Reg: 08-07-08
09-11-19 02:49 PM - Post#2775352    
    In response to gchemist


thanks for the info gchemist. I like the idea of adding air guides to close the gap between rad and condenser. What was your result when you did that?



 
gchemist 
Senior Chevytalk Moderator
Posts: 24893
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
09-11-19 07:00 PM - Post#2775364    
    In response to corvesy

A/C cooling improved at idle. Fans are quieter pulling through condenser and radiator. Engine cooling is faster. I’ll add the auxiliary fan soon. I have it wired up. I need to remove the grill for installation. The trinary switch wires will be moved to a new 100 amp relay.

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


 
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