Technical Cadillac 331 water pump rebuild

Merry Christmas Eve everyone!

I have the day off and the shop to myself so no better time to revuild the water pump on my '55 Cadillac.

It came off and apart pretty easily. I had to modify an el cheapo puller to get the impeller off but otherwise it stripped down quickly.

Its vrusty inside so I'll need to clean it out real well. My question is a hold in the bottom of the pump shaft housing. It looked like a rust hole to me but upon further inspection on the inside it looks like a weep hole. The casting has some voids where it looks like this is the case. Am I right or do I need to braze this hole closed?

Thanks all, NAES



Sent from my SM-N910V using The H.A.M.B. mobile app

 

Yes, weep hole but rusted out a bit bigger than normal. You don't really need to make it smaller again, as I doubt you run dirt roads with tons of dust that might get in there.

 

Replacements are available ( in much better condition )

 

Thanks for the quick replies guys. I already have the rebuild kit and can machine the surfaces flat.

Besides a good scrubbing and looking at the pump body for cracks, what benefit do I gain from buying another unit?

NAES

Sent from my SM-N910V using The H.A.M.B. mobile app

 

Hmmmnn, ...a lighter wallet? IDK

 

Pretty much what I figured. I'll work with this one first since I have the rebiild kit already.

Sent from my SM-N910V using The H.A.M.B. mobile app

 

Spent a little time on the water pump today, only to end up getting sidelined. I machined the bushing surface for the impeller along with the other mating surfaces and got the impeller shaft pressed in. Unfortunately the seal which is pressed on before the impeller was too long and was discovered after the impeller was half pressed on.

Long story short, the seal got destroyed in the removal process and made a mess inside the pump which will need to get cleaned up again. Everything else survived the ordeal. At least my parts source was very understanding and will get another seal out to me. This time I'll double check everything before commiting to ***embly. Could have been worse!

NAES


Sent from my SM-N910V using The H.A.M.B. mobile app

 

Finished this god damned thing up this afternoon. Not without some unnecessary headaches along the way.

I don't know about other rebuild kits out there, but this one had no insteuctions on what to do. I killed one seal but the seller spoke with his kit maker and gave me the info that needs to be included in his kits. Also, one of the bolts included in the kit snapped when I was trying to torque the rear cover down to 15ft/lbs (factory spec is 15-18ft/lbs). Turns out they were ******** import Grade 2 bolts. I was able to extract the bolt without removing the back cover or getting metal particles inside the pump. I ended up reusing the OG hardware.

For those who are going to rebuild their waterpump themselves, the bushing between the pump housing and the impeller needs to be 0.703" in height. The sleeve that the impeller is pressed onto then needs to be machined down enough to clear the rear pump cover. Factory spec clearance on the back of the pump to the cover is 0.005-0.010".

This job can't be done without either factory tools or access to a milling machine and lathe. I would say its a relatively easy job if you have the tools and instructions. I guess the proof of that will be when I bolt it all back together and see if it all works! Lol

Anyone know what the factory block color is on these things?

NAES

Sent from my SM-N910V using The H.A.M.B. mobile app

 

Is it to late to share the dis***embly process with us?
I just took the rear cover off one. But am stuck. There must be a clip I can't see. Did u press the part that holds the upper pulley off first? Did it need heat to move?

 

Sorry I don't have pics of the dis***embly process. The back cover comes off then there's the water pump inside. Thats pressed onto the shaft. I used the cheapo Harbor Freight pullers on it. If I remember right I had to grind the pullers to get them to fit into the slits in the pump.

On the front where the pulley and fan bolt I had to cut into it and split it. The pullers would grab.

Then I used a hydraulic press from the backside to push the shaft out.

As I type this I realize the front pulley piece doesn't need to come off unless it interferes with pressing the shaft off.

Any other questions please ask. I'll be more than happy to help.

NAES

Sent from my SM-N910V using The H.A.M.B. mobile app