LBZ: Lbz waterpump impeller plastic?

[slipclutchms]

Hey!
I pulled the waterpump off my lbz to tig the impeller and gear only to find the impeller is plastic.......so I went to napa to buy a replacement only to find it had a plastic impeller as well! Merchant sells a welded lbz pump so I am wondering if they press on a lb7 impeller.....or are all gm pumps steel impeller? Is it even needed on the lbz?

Thanks!
Dylan

 

[S Phinney]

Are you sure that the plastic isn't incorporated onto a steel piece that presses onto the shaft? I haven't seen one but I wouldn't think they went from plastic to the metal shaft.

 

[DMAXchris]

Yep. 06+ are plastic. You can only weld the gear side.

 

[slipclutchms]

The plastic impeller is molded onto a sleeve which is metal....then it is pressed onto the pump. I was contemplating putting a couple tacs between the sleeve and the shaft....I am assuming that sleeve is knurled and the impeller is molded around it so the point of failure would be between that sleeve and the shaft. Or by going to a plastic impeller reduce the inertia enough for it to not be a problem? I also noticed compared to the lb7 pump the gear is considerably thinner thereby also lighter.....I wonder if that was for cost cutting or again to reduce the inertia? Maybe pin the impeller?

Just thinking out loud

 

[Colt]

Maybe Eric or Tony could tell us the best way to change this so it lasts and will help to make it run longer and stay cool in real hot climates etc. Just hoping of advice from some hand who has the answer for us who need advice.

 

[JoshH]

Maybe Eric or Tony could tell us the best way to change this so it lasts and will help to make it run longer and stay cool in real hot climates etc. Just hoping of advice from some hand who has the answer for us who need advice.

I don't think it's a problem. I haven't seen nearly as many LBZ water pump failures as LB7/LLY.

 

[slipclutchms]

I ended up just welding the gear on my new pump. I did call merchant to see what there welded lbz pump is all about. I talked to roxy (sp?) who asked a few people in the shop and she said there lbz pump does have a metal impeller which is welded....I suppose it must be a hybrid lbz/lb7 pump? Are we positive that from the factory they come with plastic impellers? I did try throwing a tack weld on the impeller on the old pump to see if it would melt the impeller....sure enough glass filled nylon won't stand up to even a short tack weld

 

[RKTMech]

Yes factory LBZ+ are plastic water side impellers

 

[THEFERMANATOR]

Yes factory LBZ+ are plastic water side impellers

What he said, I have an 06 LLY one sitting in my scrap pile with a plastic impeller on it.

 

[RKTMech]

What he said, I have an 06 LLY one sitting in my scrap pile with a plastic impeller on it.

Ya what he said two, forgot about 06 LLY

 

[Colt]

Eric will get my call then on this when it craps the rack. Plastic on that what a cheap way out. It works so good with metal and more work somewhat. F the stock GM for a replacement when or if it goes while owned by me.

 

[duramax05blk]

I ended up just welding the gear on my new pump. I did call merchant to see what there welded lbz pump is all about. I talked to roxy (sp?) who asked a few people in the shop and she said there lbz pump does have a metal impeller which is welded....I suppose it must be a hybrid lbz/lb7 pump? Are we positive that from the factory they come with plastic impellers? I did try throwing a tack weld on the impeller on the old pump to see if it would melt the impeller....sure enough glass filled nylon won't stand up to even a short tack weld

Guess I was wrong spinklink



Sent from my iPhone using Tapatalk

 

[DMAXchris]

Eric will get my call then on this when it craps the rack. Plastic on that what a cheap way out. It works so good with metal and more work somewhat. F the stock GM for a replacement when or if it goes while owned by me.

The plastic ones dont really have any problems because they're lighter. It's usually rpms that kill the older ones.

 

[Robby Avery]

Glad to know this

 

[Hot COCOAL]

The Danville pump has a metal gear and impeller, I got one for my LBZ when I installed the new engine
:thumb:

 

[DaJokr]

Will the lbz suffer the same failure as the lb7's with rpms over 4k? I was under the impression the welded pumps were for just this reason...

 

[S Phinney]

I have been running one from Tony for a while nm ow with no issues. It looks like a newer pump with the housing modded to use on a lb7. Works well so far.

 

[Bikey]

Just installed a Merchant pump on my LBZ, which has a welded metal impeller.

 

[RR Worker]

So what do we do for a new LBZ housing now that GM only sells the complete pump and I can't seem to find a housing anywhere? I bought the pump from Merchant only to find that my housing is eroded inside due to electrolysis, corrosion, or cavitation when I got it apart. It's not that bad, but it went 240K on the first pump and I was planning on the second one lasting that long too. Now it looks like the pump may last and the housing might give up before the pump does. Does anybody have any suggestions other than buying a complete AC Delco pump from the Rock and putting my new Merchant pump in it? Thanks! Update: After another look at my housing, it has a deep notch in it at the point where the water outlet passage diverges from the beveled portion that the impeller runs against. I guess I need to get another complete AC Delco pump from somewhere and put my welded merchant pump in it.