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

Classic Performance Products Nu-Relics Power Windows
American Auto Wire Hellwig Products IncPerformance Rod & Custom
Danchuk Catalog



Username Post: Serpentine belt "issue"        (Topic#368444)
djackson210 
Contributor
Posts: 129

Age: 39
Loc: San Antonio, Texas
Reg: 01-31-19
05-17-22 06:36 AM - Post#2841335    

I'm working on my '89 V1500 Suburban, getting the A/C converted to R134a. I've installed a new compressor GM Genuine Parts 15-20185 & done all the other necessary retro fitting steps.

The issue is when I began charging the system yesterday. I started the truck & started charging the system with freon. I noticed the serpentine belt was wobbly where it runs between the compressor pulley & the harmonic balancer pulley, like the belt was to loose. Within about 30-45 seconds of charging the a/c system with the first can of freon the belt started slipping over the a/c compressor pulley so I shut the engine off.

I went down to my local auto parts store and bought a shorter belt. Now my belt tensioner has an up and down jump to it while the engine is idling. As if the new belt is putting too much pressure on the belt tensioner.

Supposedly the correct belt is - Dayco 5060955 with an effective length of 95.50 inches. The shorter belt I have installed now is a Dayco 5060940 with an effective length of 94.09 inches. So basically I'm runnig a belt that is 1 1/2 inches shorter than what all the parts stores say I should be running.

Before I did all this work getting the a/c system back up and running, the s-belt didn't have this looseness to it. Now with the new a/c compressor, the belt is loose. But I don't understand how a new a/c compressor could cause the "correct" s-belt to be loose? I measured the diameter of the old vs. new a/c compressor pulleys & they're the same.

I'm considering installing the GM 10129569. It's supposedly a smog pump delete pulley. I'm hoping it would take up the slop in the correct length s-belt, but I'm not sure that it would.

Any insight is greatly appreciated. Thanks!

'91 Chevy C1500 SC LWB
'89 Suburban 4WD


 
Tony1963 
Frequent Contributor
Posts: 1406

Loc: Orlando Florida
Reg: 07-09-18
05-17-22 08:12 AM - Post#2841339    
    In response to djackson210

When you say "smog pump delete" are you saying that someone has already removed one of the belt drive items (AIR pump)?

If so, that's a problem. There isn't a "factory" spec belt for a delete system so you are stuck with whatever sizes are "close".

Keep in mind that compressing the refrigerant will pass along some torsional vibrations which will be seen in the belt, but shouldn't be so much that the belt is whipping and/or slipping.

You can use any belt as long as there is some ability for the tensioner to relax, it can't be a full tension of you will break the tensioner.

Also, when I had my shop we had plenty of cases where George, Barney or Elmer put a new AC compressor on and didn't add oil to the system, thus, the compressor seized.

Without knowing, did you add oil to the refrigeration system?

People fear change because it threatens what they know, or what they claim to know.


 
gchemist 
Member #271 Senior Chevytalk Moderator
Posts: 25740
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
05-17-22 09:26 AM - Post#2841345    
    In response to Tony1963

R4 compressors take up a lot of HP. My serpentine belt would probably wobble too if it wasn't for a strong belt tensioner. An industrial belt might work better. Especially if a correct size is available. Industrial belts are thicker than automotive belts.

'83 Silverardo XST - ZZ4 powered
'95 Jimmy SLT (Bought @131,814)
'96 GMC Jimmy LS Ret. @236651 miles
'08 GMC Acadia 3.6L SLE


 
djackson210 
Contributor
Posts: 129

Age: 39
Loc: San Antonio, Texas
Reg: 01-31-19
05-17-22 03:09 PM - Post#2841369    
    In response to Tony1963

  • Tony1963 Said:
When you say "smog pump delete" are you saying that someone has already removed one of the belt drive items (AIR pump)?

If so, that's a problem. There isn't a "factory" spec belt for a delete system so you are stuck with whatever sizes are "close".

Keep in mind that compressing the refrigerant will pass along some torsional vibrations which will be seen in the belt, but shouldn't be so much that the belt is whipping and/or slipping.

You can use any belt as long as there is some ability for the tensioner to relax, it can't be a full tension or you will break the tensioner.

Also, when I had my shop we had plenty of cases where George, Barney or Elmer put a new AC compressor on and didn't add oil to the system, thus, the compressor seized.

Without knowing, did you add oil to the refrigeration system?



I'm not sure if someone removed the air pump, or if the truck came from the factory without one. I'm not at all knowledgeable about what vehicles came with them & which ones didn't. I know this has been a Texas truck it's whole life & we don't do smog tests here, so it's possible it came from the factory without one. Again I'm not sure.

The belt is definitely visibly whipping with this new a/c compressor. It wasn't with the old a/c compressor. The old a/c compressor didn't work by the way.

I did add oil directly to the new a/c compressor before running it. I poured an entire 8oz jug of PAG150 into the back of the compressor. I foolishly did not read exactly which port to pour the oil into, so it's possible I poured it into the wrong port. The port that I poured the oil into is the port with the larger hole in it. The one where you can look down into it & see directly into the inner working of the compressor. My judgement said that had to be the correct port. But I ain't no a/c guy.

  • gchemist Said:
R4 compressors take up a lot of HP. My serpentine belt would probably wobble too if it wasn't for a strong belt tensioner. An industrial belt might work better. Especially if a correct size is available. Industrial belts are thicker than automotive belts.



I'll look into an industrial belt if I can't find any other solutions. Thanks for the input.


'91 Chevy C1500 SC LWB
'89 Suburban 4WD


 
Tony1963 
Frequent Contributor
Posts: 1406

Loc: Orlando Florida
Reg: 07-09-18
05-17-22 04:57 PM - Post#2841374    
    In response to djackson210

You have an oil charge that is adequate for the AC system.

Are you sure that you have the belt routed correctly? I've seen vehicles where you could actually route the belt incorrect and still drive the accessories, however, it was not tight enough.

After putting on the belt, how much of the tensioner's range does it take to make the belt tight? Is it more than half of the range or less?

People fear change because it threatens what they know, or what they claim to know.


 
gchemist 
Member #271 Senior Chevytalk Moderator
Posts: 25740
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
05-18-22 05:24 AM - Post#2841403    
    In response to Tony1963

A Dodge truck I did an under/overdrive pulley mod required a different size belt. I could only find it in an industrial size. The belt is thick and runs smoothly.

The pic is an TBI setup found in cars and trucks. The dual belt system went away in 88.

Attachment: c10.jpg (96.94 KB) 3 View(s)


TBI serpentine belt routing.


'83 Silverardo XST - ZZ4 powered
'95 Jimmy SLT (Bought @131,814)
'96 GMC Jimmy LS Ret. @236651 miles
'08 GMC Acadia 3.6L SLE


 
djackson210 
Contributor
Posts: 129

Age: 39
Loc: San Antonio, Texas
Reg: 01-31-19
05-18-22 06:11 AM - Post#2841408    
    In response to Tony1963

  • Tony1963 Said:
You have an oil charge that is adequate for the AC system.

Are you sure that you have the belt routed correctly? I've seen vehicles where you could actually route the belt incorrect and still drive the accessories, however, it was not tight enough.

After putting on the belt, how much of the tensioner's range does it take to make the belt tight? Is it more than half of the range or less?



Yessir, I've got the belt routed correctly. Thankfully with my setup there's only 1 way to route it. If it's wrong, it's obviously wrong. I've encountered other trucks like you mention though. But this one is easy.

I can only explain the belt tensioner travel with some pictures. So I'll take a couple pictures and attach them in a following post.

  • gchemist Said:
A Dodge truck I did an under/overdrive pulley mod required a different size belt. I could only find it in an industrial size. The belt is thick and runs smoothly.

The pic is an TBI setup found in cars and trucks. The dual belt system went away in 88.



Thank goodness my TBI has the easier belt setup. The picture you attached looks like a headache inducing wasp nest!


'91 Chevy C1500 SC LWB
'89 Suburban 4WD


 
djackson210 
Contributor
Posts: 129

Age: 39
Loc: San Antonio, Texas
Reg: 01-31-19
05-18-22 06:15 AM - Post#2841409    
    In response to djackson210

I just looked at the belt tensioner again. Pictures wouldn't help at all. When it's relaxed with no belt on it, it relaxes down to the same position as it does when the belt is on it.

The belt tensioner pulley needs to come up about 3-4 inches in order to take enough pressure off the belt to be able to slip it off the alternator.

'91 Chevy C1500 SC LWB
'89 Suburban 4WD


 
gchemist 
Member #271 Senior Chevytalk Moderator
Posts: 25740
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
05-18-22 06:56 AM - Post#2841413    
    In response to djackson210

Does yours have the same setup at my signature pic? I think I have that belt size somewhere. A tensioner like mine is tight. It takes a good swing to put on and take off a belt.

'83 Silverardo XST - ZZ4 powered
'95 Jimmy SLT (Bought @131,814)
'96 GMC Jimmy LS Ret. @236651 miles
'08 GMC Acadia 3.6L SLE


 
djackson210 
Contributor
Posts: 129

Age: 39
Loc: San Antonio, Texas
Reg: 01-31-19
05-19-22 06:18 AM - Post#2841468    
    In response to gchemist

  • gchemist Said:
Does yours have the same setup at my signature pic? I think I have that belt size somewhere. A tensioner like mine is tight. It takes a good swing to put on and take off a belt.



The pic is kinda small, but best I can tell yes, my setup is laid out just like the one in the pic. Your belt tensioner pulley is swung more to the drivers side than mine is though. Mine when fully relaxed with a belt on it, the pulley sits at the 6 o'clock position.


'91 Chevy C1500 SC LWB
'89 Suburban 4WD


 
gchemist 
Member #271 Senior Chevytalk Moderator
Posts: 25740
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
05-22-22 05:16 PM - Post#2841641    
    In response to djackson210

Ok, let me look through my build notes. I’ll post the part number.

'83 Silverardo XST - ZZ4 powered
'95 Jimmy SLT (Bought @131,814)
'96 GMC Jimmy LS Ret. @236651 miles
'08 GMC Acadia 3.6L SLE


 
gchemist 
Member #271 Senior Chevytalk Moderator
Posts: 25740
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
05-30-22 03:49 AM - Post#2842019    
    In response to gchemist

Ok, I checked my records. I didn't find the size listed. The belt is worn down too so no markings are available.
Do you have your belt size? Please post it. I remember I went back twice to find a correct sized belt. When I have time, I'll take it off and have it measured at a parts store. It has few miles on it. It's time to replace it anyway with so much stress on it. I remember it's a different vehicle standard belt size.

'83 Silverardo XST - ZZ4 powered
'95 Jimmy SLT (Bought @131,814)
'96 GMC Jimmy LS Ret. @236651 miles
'08 GMC Acadia 3.6L SLE


 
djackson210 
Contributor
Posts: 129

Age: 39
Loc: San Antonio, Texas
Reg: 01-31-19
06-01-22 05:57 AM - Post#2842135    
    In response to gchemist

The standard length belt that my truck calls for is:

Dayco Part # 5060955
Effective Length: 95.50 in
Outside Circumference: 96.06 in

I also tried a shorter belt, but I didn't like the amount of stress it appeared to be putting on the idler. The shorter belt is:

Dayco Part # 5060940
Effective Length: 94.09 in
Outside Circumference: 94.75 in

'91 Chevy C1500 SC LWB
'89 Suburban 4WD


 
gchemist 
Member #271 Senior Chevytalk Moderator
Posts: 25740
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
06-01-22 06:29 AM - Post#2842137    
    In response to djackson210

Okay, there are two sizes between the two belts. One of them should work.


5060940 6PK2390 94.09 OD 94.75 ribs 6

5060945 6PK2400 94.50 OD 95.16 ribs 6
5060950 6PK2415 95.08 OD 95.64 ribs 6

5060955 6PK2425 95.50 OD 96.06 ribs 6
5060960 6PK2440 96.06 OD 96.62 ribs 6

'83 Silverardo XST - ZZ4 powered
'95 Jimmy SLT (Bought @131,814)
'96 GMC Jimmy LS Ret. @236651 miles
'08 GMC Acadia 3.6L SLE


 
djackson210 
Contributor
Posts: 129

Age: 39
Loc: San Antonio, Texas
Reg: 01-31-19
06-13-22 06:23 AM - Post#2842821    
    In response to gchemist

  • gchemist Said:
Okay, there are two sizes between the two belts. One of them should work.


5060940 6PK2390 94.09 OD 94.75 ribs 6

5060945 6PK2400 94.50 OD 95.16 ribs 6
5060950 6PK2415 95.08 OD 95.64 ribs 6

5060955 6PK2425 95.50 OD 96.06 ribs 6
5060960 6PK2440 96.06 OD 96.62 ribs 6



Most excellent! Thank you for all the info.


'91 Chevy C1500 SC LWB
'89 Suburban 4WD


 
gchemist 
Member #271 Senior Chevytalk Moderator
Posts: 25740
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
06-14-22 03:59 AM - Post#2842889    
    In response to djackson210

Let us know which of the these works best.
5060945 6PK2400 94.50 OD 95.16 ribs 6
5060950 6PK2415 95.08 OD 95.64 ribs 6

I'll the size add to my truck parts list for future replacements and reference.

'83 Silverardo XST - ZZ4 powered
'95 Jimmy SLT (Bought @131,814)
'96 GMC Jimmy LS Ret. @236651 miles
'08 GMC Acadia 3.6L SLE


 
djackson210 
Contributor
Posts: 129

Age: 39
Loc: San Antonio, Texas
Reg: 01-31-19
06-18-22 08:09 AM - Post#2843075    
    In response to gchemist

Right now I'm running the Dayco 5060940 & it seems to be great so far.

I went ahead and reverted back to the factory style belt tensioner also. I was running the Dayco 89201. Supposedly it was a "demanding drive" tensioner, so I assumed it would be a stronger/better belt tensioner. But it's possible it was playing a role in the sloppy belt.

But now with a factory style belt tensioner & the somewhat smaller belt, all seems well. No slack in the belt & it also doesn't seem overly tight either.

Thanks again for everything!

'91 Chevy C1500 SC LWB
'89 Suburban 4WD


 
Icon Legend Permissions Topic Options
Report Post

Quote Post

Quick Reply

Print Topic

Email Topic

644 Views
FusionBB
FusionBB™ Version 2.1
©2003-2006 InteractivePHP, Inc.
Execution time: 0.16 seconds.   Total Queries: 18   Zlib Compression is on.
All times are (GMT -0800) Pacific. Current time is 09:58 AM
Top