THOSE GREAT SAGINAW WORKERS! 1985 442 PS Pump Rebuild (GM P/N 7840244)

oldsofb

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Dec 7, 2007
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When I apprenticed at the dealership, I was shown to clean the rotor wheel and vane tops insitue and then mark the top inner all the way around with a sharpie. Then when you were putting the vanes back in you knew what was top inner. That's how I did every one. Once installed you could swipe your marks off with brake kleen on a towel.

Lots of good detail here. Well done.

Hutch
 
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69hurstolds

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Jan 2, 2006
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When I apprentice at the dealership, I was shown to clean the rotor wheel and vane tops insitue and then mark the top inner all the way around with a sharpie. Then when you were putting the vanes back in you knew what was top inner. That's how I did every one. Once installed you could swipe your marks off with brake kleen on a towel.

Lots of good detail here. Well done.

Hutch
Thanks. That's a great idea. Where were you last week? :) I just lined them up on a paper towel in a circle arrangement with bottoms pointing counter clockwise and wear marks down. It worked out, but still. If I'd have accidently picked up the towel and dumped them over, then I'd be back to square one.

So I finally got the reservoir cleaned up and straightened the bolt holes. Compared the old vs. new O-rings and guess what? The directions in the kit says if there's an X molded on one of the bosses, to use the thicker gaskets. If not, use the thinner ones. Well, there's no "X" on the boss, yet this particular pump utilizes the THICKER gaskets. No big deal, but just be aware. The major issue with the kits are that they used the same part number across a larger number of pumps, so engineering changes along the way may or may not coincide any longer with the then-current instructions. I reinstalled the shuttle valve and noted it has TWO shims in it. I did not disassemble it, but only cleaned it well. I have a metric click torque wrench so torqued the bolts to 24, then 48 N-m. And then 26 and then 50 N-m on the HP outlet fitting.

Here's a pic of the outlet fitting with the shuttle valve diassembled. Note it has 2 shims.

1717959044798.png


I cleaned up the cap and reinstalled it, and that's when I noticed that it appears the pump must've dropped on its head when it was a baby. The neck of the reservoir is bent slightly forward and the area where it enters the top front of the reservoir is slightly dented in behind the flange making it slightly cocked forward. Didn't notice it before but it appears somehow it took a blow to the head somewhere. I know I didn't drop it. And nobody I'm aware of has ever changed the belts but me (one time), and I used a turnbuckle assembly to do that.

One detail I did note was a stamping on the back of the reservoir saying "023B5R". Not 100% sure how to read that. It may be a date stamp. Which may equate to the 023 day of year (Wednesday, January 23), "B" shift, or 2nd shift, 5- year, 1985, and R- Totally unknown. Might be the type of pump? Rotary vane perhaps? I don't know. It would certainly fall in line with the suspected 2nd week of Feburary build. Hope I can find the build sheet one of these days.

Anyway, the last little detail I'm going to install is a repro "laser etched" decal with the part number and factory assembly pick code on it. Goes on the outer side of the pump reservoir away from the engine, sideways. I had to emulate the laser etching because I can't duplicate it exactly. I've seen repro decals for these, and they're FAR from looking like the originals. I think mine are better.

Here's the build sheet for my gray 85 442, and it has the NP pump and LA (double groove) press on pulley.
Gray 85 442 Build sheet PS pump code.jpg


IMG_0196.jpg


Here's one on an NOS pump I used to mimic my version. The 30687A on it may be a date code. I'm actually not sure. I didn't bother to figure out what the alpha-numeric sequence stood for when I made it. Should it match the stamping on the rear of the reservoir? Could it be 306 day of 1987, first shift? Monday, November 7, 1987 for model year 1988s? I've seen other pumps with different codes and that code looks completely different so I'm not sure. Ironically, my car did not have one, but probably should have. Whether it fell off or what, I dunno. I just haven't seen any evidence it was there. Maybe it fell off when the baby got dropped on his head. They're hard AF to see anyway based on where they are, but again, mine came naked. The decal's pretty cool as the laser etching leaves a silver glittery look to where it engraved the info. If you have an original, check it out.

7840244 NOS PS Pump Decal NP.jpg


Just for S&Gs, here's one of those other guys' "repro" decals. I think it's for a generic Chevy truck 1987 2WD 350 Chevy pump, but they advertise it fitting every PS pump out there. Still doesn't look even close.
k-dc12_20220726160721.jpg


I almost forgot to do it, but ran a 3/8-16 tap down the shaft hole to clean up the threads for the pulley installer tool- and now I'm done. Putting it in a box and waiting until I need to reinstall it.

Everything was douched in new Lucas PS fluid as I was putting it back together, and I think that's what I'm going to use as fill fluid in it when done. I thought about using vaseline for assembly, but why? PS fluid is what it will live in anyway. Put a bolt into the end of the shaft to turn it a little and it turns smooth as glass, no scraping or hard spots. Beautiful.

IMG_0199.jpg


The price with trade-in for a "rebuilt" pump is still like $50 or so. If your internal components are in good shape, just cleaning it up and resealing it and making it look good again can get you miles more down the road for less than $25-30 bucks with a reseal kit and some new fluid. If your sh*t is broke or buzzing/rattling, then by all means, trading it in is probably a good idea. But it takes a little bit more work to rebuild yours which you know is correct for your car as it does just to swap it out. When putting the pulley back on, try to get it back in the correct spot it needs to be, regardless of position on the shaft. It could be flush, or plus or minus a little of flush. You just want to make sure the sheaves line up properly with the others for perfect belt alignment.

That's it folks. I hope y'all learned a little sumpin'. I know I sure did. Did I HAVE to rebuild/clean this thing/check components and reseal it? No. I could have just swapped it out with the NOS pump. But it was another little bucket list item I wanted to tackle to see if I could do it. It's not a very difficult pump to disassemble/reassemble, but be aware not every pump exhibits the same details as others. At least I know what I'm starting with.
 
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