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best compressor?

bigkev on Thu May 06, 2010 2:37 AM User is offline

Year: 1990
Make: chev
Model: c1500
Engine Size: 4.3
Refrigerant Type: r134

About 2 years ago I put ac on my 1990 chev truck. I used a new evap, new lines, made a newer serpentine condenser fit in it, adjustable cycling switch, and rebuilt r4. From what I have researched it seems that these rebuilt r4's are garbage because they cannot be cost effectively built without cutting corners. This rebuilt compressor only seemed to work good for a few months and then turned into a noisy turd. The clutch is already worn out (doubt it was new) and now its got some really bad internal noise. Thank you big box store for your fine product. So Im just gonna break down and bite the bullet and go new I think. My question to you guys is where can i buy a new r4 that will for sure be new. Im a little scared of buying new off ebay or at a big box chain. So if anyone could tell me where to get a new one from someone who wont send me more junk i would be grateful. I had one other idea, I seen this site sells universal seltics anybody try one yet? I also heard the sanden compressors are kinda good. I can weld and braze so making one mount wont be a huge issue. Should I expect better performance or reliability with either of these compressors or you think ill be happy with a new r4?

HVargas on Thu May 06, 2010 11:22 AM User is offlineView users profile

We do sell universal Sanden compressors and a bracket to mount it on your engine but you can get a new R4 from us here, 20-10457-H.

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Edited: Thu May 06, 2010 at 11:23 AM by HVargas

iceman2555 on Thu May 06, 2010 5:02 PM User is offlineView users profile

The failure of your compressor is probably due to the failure to properly service the system. This is a common cause of compressor noise/failures with retro fitted vehicles. This was a major contributing factor to a drastic increase in compressor failures during the 'hey day' of retrofitting. The problem is the installers assumption that a system can be properly charged by adjusting pressures to obtain properly charged system. This is almost an impossibility with a modern system and even more so for a retro fitted system.
Failure to properly charge the system will result in the same failure....new...reman'd....Sanden.....what ever compressor is installed on the unit.
It is essential that the system be completely charged, the vehicle cooling system 100% operational.
There is a valid test for charging a retro fitted system. This procedure involves the use of temperature drop test instead of simply charging to a pre conceived pressure/vent temp.


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The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

bigkev on Wed May 12, 2010 3:06 AM User is offline

bigkev on Wed May 12, 2010 3:10 AM User is offline

I did charge this system using a superheat method (correct way to say for automotive?) and i measured how much i put in just so I would know in the future. Every part of the system was brand new except the compressor. I have heard to many bad things about these rebuilt compressors to think that I charged it wrong. I triple checked everything i was doing and then checked some more. Im going to try a new one from here I think.

Cussboy on Wed May 12, 2010 9:47 AM User is offline

I believe that I read something about rebuilt R4 compressors here on this board. Something like to rebuld one correctly would cost more than the rebuilt ones are sold for, so one is recommeded to get brand-new instead. So I just replaced my leaky R4 in my 1994 dual-air Suburban with a brand-new Delphi R4 unit in March (factory R134a). I had to buy one extra O-ring for that as one of the ones in the new accumulator box was too narrow.

By the way, the old R4, which was not seized up, was out of refrigeration oil; the old accumulator contained about one drop oil. I had replaced the manifold line assembly 2009 due to crimp leak, and the old compressor itself developed the notorius belly leak. Maybe I had lost more oil out that bad crimp over time than I had thought.

I was fully aware that the R4 is a crappy compressor, but upgrading to a Sanden or similar aftermarket compressor, getting such mounts, and getting custom-made manifold for such compressor was just too &*$%#%&(^$^& expensive for me, '94 withover 200K miles on it.

Edited: Wed May 12, 2010 at 3:07 PM by Cussboy

ice-n-tropics on Wed May 12, 2010 2:10 PM User is offline

Big,
All available R4s are not worth a warm bottle of spit (as we say in Texas) as compared to Seltec or Sanden SD7H15. One primary reason is that the aluminum housing is porus because all R4 manufactures have always used a leak prone gravity casting process instead of a squeeze casting process or a high pressure die casting.
I've watched reman R4 activities several times and please don't go there. For example, The clutch friction surfaces are remachined which thins the metal that must conduct the magnetic flux. Thinner than original metal pulley and armature friction surfaces reduce the magnet-motive attraction force, and more engagement slip and heat is induced.
GM's Harrison division moth-balled their in house R4 facility (that I saw in Dayton) some 5 to 8 years ago because of horrible warranty rates. GM/Delco may still buy and distribute R-4s from independent suppliers.

R-12 or R-134a charge of orifice tube/accumulator systems can be done better than by using a superheat field test, therefore forget SH.
Step 1:
Be sure that the A/C system with compressor contains a minimum of 9 oz. of lube.
Step 2:
You can feel the evaporator outlet pipe while touching the inlet pipe downstream of the orifice tube (with temperature calibrated fingers). When refrigerant quantity is charged until the outlet tube is as cold as the inlet pipe then go to step 3.
Step 3:
For a old 1990 A/C GM add 2 additional ounces of refrigerant as a reserve for refrigerant seepage.
Cordially.
hotrodac


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Cussboy on Wed May 12, 2010 3:03 PM User is offline

Quote
Originally posted by: Cussboy
I believe that I read something about rebuilt R4 compressors here on this board. Something like to rebuld one correctly would cost more than the rebuilt ones are sold for, so one is recommeded to get brand-new instead. So I just replaced my leaky R4 in my 1994 dual-air Suburban with a brand-new Delphi R4 unit in March (factory R134a). I had to buy one extra O-ring for that as one of the ones in the new accumulator box was too narrow.



By the way, the old R4, which was not seized up, was out of refrigeration oil; the old accumulator contained about one drop oil. I had replaced the manifold line assembly 2009 due to crimp leak, and the old compressor itself developed the notorius belly leak. Maybe I had lost more oil out that bad crimp over time than I had thought.

I was fully aware that the R4 is a crappy compressor, but upgrading to a Sanden or similar aftermarket compressor, getting such mounts, and getting custom-made manifold for such compressor was just too &*$%#%&(^$^& expensive for me, '94 withover 200K miles on it.



Edited: Wed May 12, 2010 at 3:07 PM by Cussboy

iceman2555 on Wed May 12, 2010 5:56 PM User is offlineView users profile

The major cause of compressor noise is lack of lubricant. The R4 is totally dependent upon refrigerant level and flow to maintain lubricant migration. I stand by my original statement, no matter what late model compressor is utilized, if the amount of refrigerant is insufficient to maintain lube flow the compressor is going to 'die'. The statement that the compressor operated for several months and then developed noise and clutch issues in normally indicative of loss of lubricant flow back to the suction side of the compressor, thus allowing for compressor lube replenishment. This is often compounded by the process of retro fitting and attempting to charge utilizing a % of 134a to 12 specs.
Cussboys statement concerning the 'old r4' lock up and no lube in the compressor or in the accumulator is also indicative of a system with insufficient refrigerant. He stated that the system leaked at a crimp and he felt the system loss too much lube. The system did not loose that much lube...the system lost the ability of the system to maintain lube flow to the compressor due to an undercharged system. This is probably the same issue that 'bigkev' experienced. His problem could be an undiagnosed leak or an undercharged system.
I am not sure what 'superheat' was used in determining the charge rate...however, the fact remains that the evap must be 'flooded' to maintain lubricant flow. As the other 'ice' stated, the inlet and outlet must be the same temp.....the system is completely charged. I, too, like the idea of a couple extra oz added to the system. The down side is that the system can not be short refrigerant.....then the lube flow goes away. One will find the majority of the lube encapsulated in the evap core. This is the issue that 'cussboy' experienced. There was insufficient refrigerant level/flow to replenish the accumulator and the system pumped dry.
Bigkev when the compressor is removed from your vehicle....drain the suction side of the compressor and post the result....would be interested in this information.


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The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

Dougflas on Wed May 12, 2010 10:48 PM User is offline

Just want to say that I'm still running a 88 Chev van G20 305 engine with 99890 miles. Same oem R4 and accumulator. All I've done to this ac system is change a high side hose, evacuated system to 500 microns, add 2 oz mineral oil and r12. Compressor is quiet and I get under 48º vent temps. I'm in Florida and have used the ac system all the time.

Cussboy on Thu May 13, 2010 9:44 AM User is offline

Quote
Originally posted by: iceman2555
Cussboys statement concerning the 'old r4' lock up and no lube in the compressor or in the accumulator is also indicative of a system with insufficient refrigerant. He stated that the system leaked at a crimp and he felt the system loss too much lube. The system did not loose that much lube...the system lost the ability of the system to maintain lube flow to the compressor due to an undercharged system.

Agree, on mine I might have lost enough refrigerant from the leaky high side crimp to cause oiling issues, which ended up hurting the compressor a year later.

Good luck on getting Mrs. Cusser to obey instructions about not using AC when it was marginal, before I could fix it. Even in "winter" here, a vehicle parked in the sun for half an hour becomes 140F inside....I can't even get her to turn lights off when she leaves, it's like they're all "one-way" switches to her.....she has good qualities, too.....



Edited: Thu May 13, 2010 at 9:47 AM by Cussboy

dockyN on Tue May 18, 2010 1:02 AM User is offline

Agreed!

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