Hey all, Here's another post with videos I did. My 49 GMC water pump was leaking a little bit, not to mention the bearing was pretty loose. So much so that you could visibly see the play when I pushed/pulled the fan. While the engine was apart and the pump was already out I decided to do something about it. The GMC water pump is a bit different from the Chevy, and they seem to be less available than the Chevy Pumps too. I saw a few on ebay going for $200-300. I found a rebuild kit sold on ebay for $120, which is still pricey, but fairly reasonable. Plus I would get to learn how to rebuild one of these. Process went pretty well. I did accidentally break the new seal when pressing the impeller back on, but fortunately the seller offers just the seals for sale. Rebuild went well. It has not been run yet as the engine is still being reassembled.
Part 1: Remove the fan pulley: Part 2: Remove the back plate: (mine required a drill press, hopefully your screws will back out easily Part 3: Pressing out the shaft: Part 3a: Get the dang back plate screws out: Part 4: Start the reassembly, impeller seal: Part 5: Impeller on, next steps: Part 6: Finishing the final reassembly:
I wonder why a halfway competent machinist couldn't make his own shaft and bearing assembly, using readily available standard parts, and not have to pay an outrageous price for somebody's "kit"? Even if the shaft needs to be hardened for some reason, either air, water, or oil hardening drill rod is available in all sorts of sizes, annealed for machining and able to be hardened as a final operation. I can't really see a need for hardening the shaft, however! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Ed, is that for the 503? I believe I can fabricate or adapt the parts needed to rebuild that pump, especially if you have a spare unit I can tinker with without taking the big rig out of service. PM or email me if you'd like to discuss it. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Hey all, Thanks for the good feed back. Hotrod Lincoln - the guy selling them probably had your exact idea and said the same thing- I can make these things, haha. I did just get a mini lathe I'm learning to use, that bearing and shaft could be the first project for me maybe. Not sure if the bearings themselves are custom or if they can be found. His ebay Store is here: https://www.ebay.com/usr/2ndgenautoparts. Greg
I believe any Torrington needle bearing of appropriate size can be incorporated into a shaft/carrier assembly that can be pressed into a pump housing. Instead of using pre-lubed sealed bearings, I'd probably drill and tap the pump casting snout for a grease fitting so the bearing could get a shot of lube periodically. From there, it's just a matter of fitting a mechanical seal to the coolant side of things and a pulley/fan flange and an impeller. With some careful disassembly, the flange and impeller can probably be re-used. I'd probably make some sort of puller to remove the impeller from the back side by drilling and tapping a couple of holes into it so a puller could be used on it. I don't think two or three small threaded holes would affect the performance of the impeller. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
