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A/C compressor trivia

J_dude

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Ok this technically isn’t a specifically Diesel engines question, but both vehicles involved are diesel so close enough lol. Any A/C guys on here?

The Backstory:
I have an old A/C compressor that came off my ‘03 Jetta TDI, it’s still in good shape, (I think now that I have it apart it must’ve just needed a new pressure control valve) so I am going to attempt to make use of it as an on board air compressor on my 12 valve Cummins.

The Problem:
The Cummins has an 8-rib serpentine belt, whereas the Jetta A/C compressor’s pulley is only 6-rib.

Solution: (not so fast!)
Need to get a new clutch/pulley that is for an 8-rib belt...

HOWEVER!
I can’t find any information in the Sanden Parts Catalog about this model of compressor, it is an SD7V16H (variable displacement) but the catalog only lists parts for the fixed displacement compressors. Like the SD7H15 or others in the SD7 series.

The Question:
So what I need to know is; Will any SD7 fixed displacement series clutch fit any other SD7 compressor?

Thanks,
Jude
 
I suggest hitting a junkyard and grabbing a fixed displacement SD7 series with the correct pulley. I wouldn't bother with a variable displacement mess myself after the cheap common Sanden junkyard pull. Clutches are expensive to order sometimes being more than a new compressor.

How much air do you need? Many better choices out there depending on what you are doing. Like York compressors, as you should know, has it's own oiling system.

Some other option:

 
I suggest hitting a junkyard and grabbing a fixed displacement SD7 series with the correct pulley. I wouldn't bother with a variable displacement mess myself after the cheap common Sanden junkyard pull. Clutches are expensive to order sometimes being more than a new compressor.

How much air do you need? Many better choices out there depending on what you are doing. Like York compressors, as you should know, has it's own oiling system.

Some other option:

Well that might be the smarter idea yes 😂. But I just wanted to use this one since I have it laying around, and I prefer the mounting points on it to the other ones people usually use for OBA.
Yorks are bulky and they’re lots harder to find, not to mention these swashplate Sandens have better CFM, especially for their size. Not hard to plug the oil bypass port in a Sanden and run grease, lots of guys do.
Anyway I just thought $100 for a clutch vs whatever they would charge (probably at least that much) for a used one at the pick n pull that might be on its way out already, was a better option, given that I know this one is okay already.
 
I think that’s what I’ll have to do. That’s a custom fan pulley, but I think I have an idea how to make one. Going to be tricky as I don’t have access to a lathe any more but I think it’ll work. Also have to make an extra tensioner pulley, that’s the hard part.
It sucks to lose access to equipment.
I always wanted a 1/4" x 10' press brake.
 
I would enjoy write up when you do it, whichever way you go.

Maybe try contacting sanden directly about a part number for the 8 rib clutch?

Advantage of adding pulley - just make the pulley but do the bracket so it is adjustable rather than buying a tensioner and adapting it also. Simply to 1/8” plates with welded hinge joining them. Mount the plate to engine where you would have mounted pump.
Mount pump to other plate. Weld on a coupling nut on compressor plate mount so it has large area to shed load. Bolt goes through it and hits a tab on bottom plate. Be sure to add a jam nut.

Interested to see how they convert to grease instead of oil. I have an old york I saved for this but size and cost of serpentine clutch is why it hasn’t made it to my hummer in last 15 years. When my electric on board compressor dies- i will force myself into making the switch to belt driven. Air tools was a motivator but cordless has come so far, now only desire is for tire deflation/inflation off roading and get my triple tone toot-toot mounted. And at 200ish psi- All the above would be nicer!
 
Got the mount bracket almost finished yesterday. Probably going to use an old tensioner I have lying around. Also messed around with the second pulley a bit, think I’ve got a plan of attack now, just hope I can weld the center in without warping the pulley... 😬5FDDDF23-C4E6-4DC9-8A00-206C41BC1448.jpeg02BB1E4A-8DDE-4D10-92AC-9C0CC23F8283.jpeg67E528C6-7D33-4D3C-BA33-193F8C1CC9C5.jpeg
Greasing these isnt hard, just have to pull it all apart and clean the oil out, tap and plug one hole btween the head and crankcase then pack er with grease. Oil is better for longevity but they pass too much oil by the rings so you’d have to keep topping it up. Some guys try and use an air tool oiler on the suction/intake side but they burn up because none of that oil makes it to the crankcase lol.
Mine was a little more complicated because it’s a variable displacement so I had to do a lot of searching to find out how to make it run fixed. Not hard to do just have to remove the little valve thing inside and replace with a bolt. The hard part was finding that info lol.
 
Got the mount bracket almost finished yesterday. Probably going to use an old tensioner I have lying around. Also messed around with the second pulley a bit, think I’ve got a plan of attack now, just hope I can weld the center in without warping the pulley... 😬View attachment 81607View attachment 81608View attachment 81609
Greasing these isnt hard, just have to pull it all apart and clean the oil out, tap and plug one hole btween the head and crankcase then pack er with grease. Oil is better for longevity but they pass too much oil by the rings so you’d have to keep topping it up. Some guys try and use an air tool oiler on the suction/intake side but they burn up because none of that oil makes it to the crankcase lol.
Mine was a little more complicated because it’s a variable displacement so I had to do a lot of searching to find out how to make it run fixed. Not hard to do just have to remove the little valve thing inside and replace with a bolt. The hard part was finding that info lol.
How about pouring in more than enough oil, then, rig a hose between the pressure and the vacuum ports ?
That way the oil would keep circulating and the rotor stay lubed.
 
How about pouring in more than enough oil, then, rig a hose between the pressure and the vacuum ports ?
That way the oil would keep circulating and the rotor stay lubed.
That’s kinda the idea behind the in-line tool oiler thing, but the trouble is that oil would only circulate through the head, and never get down to the swashplate in the crankcase. If you could rig something the would dump the oil back into the crankcase fill hole then I suppose that could work too, not sure how complicated that would be.

@Will L. I forgot to mention I did email Sanden about the 8 rib clutch but haven’t received any reply yet.
 
I would enjoy write up when you do it, whichever way you go.

Maybe try contacting sanden directly about a part number for the 8 rib clutch?

Advantage of adding pulley - just make the pulley but do the bracket so it is adjustable rather than buying a tensioner and adapting it also. Simply to 1/8” plates with welded hinge joining them. Mount the plate to engine where you would have mounted pump.
Mount pump to other plate. Weld on a coupling nut on compressor plate mount so it has large area to shed load. Bolt goes through it and hits a tab on bottom plate. Be sure to add a jam nut.

Interested to see how they convert to grease instead of oil. I have an old york I saved for this but size and cost of serpentine clutch is why it hasn’t made it to my hummer in last 15 years. When my electric on board compressor dies- i will force myself into making the switch to belt driven. Air tools was a motivator but cordless has come so far, now only desire is for tire deflation/inflation off roading and get my triple tone toot-toot mounted. And at 200ish psi- All the above would be nicer!
Yeah, my old '72 Dodge D100 had that glorious Chrysler 2 cylinder A/C pump on it. I STILL kick myself in the ass for not removing it when I had it towed off to the salvage yard. I could have made a really kickass air compressor with it and a spare 2hp electric motor I had, or years later I could have mounted it on my '94 C2500 6.5TD engine for jobsite air when an AC outlet wasn't available within a 100' extension cord reach for the compressor for the nailguns.
 
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