New guy needs help with PS pump

[PDSM]

Hi Folks,
I just bought a '76 C10 pickup, and have been searching the web for answers to a few questions I have about the truck. Fortunately, I stumbled across gmsquarebody.com, and found the answers to all but one of those questions. THANKS!

Now for the question I didn't find an answer to... My power steering pump belts are seriously out of alignment, not just that the pulleys aren't coplanar, but also that the pump's axis does not appear to be parallel to the crankshaft. When I started digging into it I found that someone had added a roughly 1/4" thick spacer to the driver's side pump bracket where the adjustment slot is. No wonder they're misaligned, right? (sorry, I didn't think to take a picture at that stage.)

At this point I should mention that my truck was originally equipped with a 350 engine, power steering and air conditioning. The previous owner had the engine replaced with a GM Goodwrench crate 350 with long water pump, which if I understand correctly should be right for the truck. I assume, but really don't know for sure, that he just reused the accessories and brackets and such from the old engine.

So I take it all loose to try to get everything back in alignment, and I think I understand why he added the spacer. (Not that it was the right thing to do, but the reason he did it...) When I took out the spacer, the top rear edge of the PS pump reservoir hits the lower edge of the a/c compressor bracket that is bolted to the head. See attached photo "Interference with ac compressor bracket"

So the interference between the reservoir and the compressor bracket makes for about a 3/8" gap between the PS pump bracket and where it's supposed to attach. I guess he just filled in the gap with that spacer, clamped it down, and went his merry way.

If I rotate the pump clockwise to the point that the reservoir is below the bracket and doesn't interfere, it appears that the pulleys will line up pretty well. See attached photo "Too low 1." The problem with that is that the top edge of the PS adjusting slot is about 1/2" below the bolt hole, so it can't work that way. See "Too low 2."

I wondered if along they way the PO had used incorrect brackets, but in looking at the illustrations in the service manual, it appears that I have all the correct mounting brackets for this model year and option combination.

I also noticed that in the '74 manual it shows a different style reservoir with an oval cross section (like this: https://www.napaonline.com/napa/en/p/NSP816635F/NSP816635F_0212493958)

whereas in the '76 supplement it has the typical squarish teardrop shape that I'm most familiar with (and is what is on this truck.) In looking at RockAuto and other such places it seems like the oval reservoir may be more correct for trucks through '72, but I'm not sure. It does appear that this reservoir is slanted forward so it may give me more clearance for the compressor bracket.

Have any of you ever had this interference problem? If you have a similar configuration (350 V-8 with PS and A/C) what type of PS reservoir do you have?

Thanks for your help!

 

[chengny]

The process of lining up the PSP pulley on a 350 can get involved. You may be working with brackets and hardware from a number of different applications and it's hard to tell which parts truly belong and which were accumulated over the life of the truck. And, when integrating the PSP mounting components with an A/C compressor, things can get really confusing. For example, you didn't mention what style of compressor you have installed - but I bet it's an R-4. The stock compressor for your model year with a V-8 is an A-6.

The pump body style is not an issue (BTW - you have the correct style):

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This is how I align the pulleys when working with a modified/altered engine:

1. The position of the water pump/fan/alternator pulley is non-negotiable. Mount that
pulley right up to the water pump flange and leave it. Don't be tempted to shim it to
line up with any other pulley. This will be the baseline, everything else will be lined up with it.

2. With that pulley set in place, check its alignment with the crank pulley. In this case all
you will be checking/adjusting is the parallel alignment. If any angular misalignment exists between these two shafts...you have bigger problems than the PSP. Checking these two pulleys for parallel alignment can be a hassle. It is a lot easier with everything else still on the bench. But sometimes that isn't possible. Because the faces of the pulleys are of different designs and the thickness varies, I find it best to use the back sides. Also the back groove is where the common crank/fan/PSP belt rides. Take a thin straight-edge and lay it along the back of one the pulleys (the one closest to the engine). Note the gap between the straight-edge and the other pulley - if any. Since the top pulley is the benchmark, the harmonic balancer will need to be shifted either in or out on the crank snout to obtain alignment. When you have the back groove on both the upper and lower pulleys in exactly the same plane...you can move on to the PSP mounting.

3. I won't even try to offer any advice on how you should/could align the PSP pulley. You are there and know what you have for bracketing. Also you can add shims where necessary. But when you are done, you should have something like this:

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Note: The image on the left is misleading. It appears like the PSP pulley is not in angular alignment but it is an optical illusion. I made sure - after I looked at the photos.

After that, the alternator pulley generally falls right into place and you don't have any smog pumps so the only thing left is the A/C compressor. As noted above the standard compressor spec'd for this engine was an A-6. If you are mounting an R-4 you will have to use your imagination.

If you are using the same belt to drive the PSP and the compressor, it might look something like this (if you have an R-4):

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The PSP and A/C compressor mounting details:

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[PDSM]

PSP alignment

I actually do have the A-6 compressor, so at least that's "right." Crank/WP/alternator pulleys seem to be in good alignment already. At least I know now that I have the right PSP, so I won't go barking up the wrong tree there. I'll keep digging in to the PSP brackets and such.

Thanks for your help!

 

[PDSM]

I've got all my belts lined up now. Thought I'd post back in case anyone else ends up with the problem I had...

Chengny had it correct from the beginning of his post. I had the original '76 PSP brackets, but the replacement engine had a newer water pump. Apparently in '77 GM changed the bracket design from one that bolted through a clearance hole on the water pump, to one that bolted to a threaded hole on the water pump. See explanation at another forum http://67-72chevytrucks.com/vboard/showthread.php?t=610250

For those so inclined, I tried drilling out the threads to work correctly with my '76 PSP bracket, but it would also require grinding out some material on the back side of the water pump so that the bracket can fit. Since RockAuto has the water pump for less than $20, I just replaced the water pump.