LB7 LLY Water pump fix-is there a solution?

[Kennedy Diesel]

Am I chasing my tail or can a guy pin these together and make them live? I lost the bearing/seal on one on Saturday (welds held) and on Tuesday I spun the impeller tig weld and all.

Thinking maybe the pin at the parting line might work...

I'm trying to avoid the electric pump, but if that is what I need to be reliable then so be it.

 

[coldLBZ]

Here is a thread about electric water pumps, and I also linked to another thread about the water pump issues on page 5.
http://www.duramaxdiesels.com/forum/showthread.php?t=22795
Hope this helps you John.

 

[Chevy1925]

i swore someone has attempted that or done it. i remember reading about it a long time ago. i thought they had issues trying to drill the shaft part. i also dont know if there was any follow up after it was done

 

[maine04max]

I took one to a machine shop and they were not interested in trying to pin it due to shaft hardness

 

[bullfrogjohnson]

Anneal the shaft. Then you can machine a keyway. Drill and tap the snout, use a bolt and retainer to keep it on the shaft.

 

[Kennedy Diesel]

Has anybody failed or heard of a failed water pump on an LBZ?

It seems this is unique to the LB7 and LLY.

There was a blog on Diesel Power where they showed a drilling operation where they drilled lengthwards to the shaft 1/2 in the impeller and 1/2 in the shaft using a carbide end mill.

 

[blackdirtymax]

Has anybody failed or heard of a failed water pump on an LBZ?

It seems this is unique to the LB7 and LLY.

There was a blog on Diesel Power where they showed a drilling operation where they drilled lengthwards to the shaft 1/2 in the impeller and 1/2 in the shaft using a carbide end mill.

I went threw two pumps on my lbz and finally just broke down and bought a brand new GM pump. Since then I haven't had an issue yet( knock on wood ).


Built motor , duel fuelers , 60's overs , gtx4202r

 

[juddski88]

there have been lbz pump failures but not as many. I think it mightve been Travis who finally found a method of pinning the shafts that actually lasted

 

[bcdeutsch731]

Danville Performance drills through the impellers and shaft and pins them together. They have a machine shop in house and have the pumps on the shelf ready to go.

 

[Tony Burkhard]

there have been lbz pump failures but not as many. I think it mightve been Travis who finally found a method of pinning the shafts that actually lasted

do we know who had lbz failures so we can talk to them? I'm adapting an LBZ pump for John and will do more if I know they work. Any one I have asked have not heard of an LBZ failure.

 

[Kennedy Diesel]

Tony scooped me here, but yes Tony is working on a solution for me based on a discussion we had. I think conventinal wisdom has been barking up the wrong tree with flow resistance and pressure being the focus. I think it's simpler than that.

Now the hard part is the wait...

 

[Kennedy Diesel]

I went threw two pumps on my lbz and finally just broke down and bought a brand new GM pump. Since then I haven't had an issue yet( knock on wood ).


Built motor , duel fuelers , 60's overs , gtx4202r

What pump did you use and how did they fail? Leak, spin out, blow up?

 

[Tony Burkhard]

shipping pump out today.

 

[blackdirtymax]

What pump did you use and how did they fail? Leak, spin out, blow up?

I got both pumps from advance auto with a warranty . The first one lasted about a month , as I was leaving a red light I barley rolled into the throttle , and spun the impeller clean off the shaft . They replaced it no questions asked , second lasted about three months and did the same but also took out the housing . I decided then to use a new GM pump , and have been okay ever since.


Built motor , duel fuelers , 60's overs , gtx4202r

 

[THEFERMANATOR]

Are the LB7/LLY water pumps that are letting go genuine GM or are they aftermarket pumps as well? I know I have had problems with aftermarket(autozone and advance) water pumps in other applications here lately. I put a genuine AC DELCO from GM in my BURB, but then again I'm only running around 400HP to the wheels on mine(can't afford to play in the big boy HP league).

 

[Kennedy Diesel]

I can't say as that they are different AC Delco versus Genuine GM. Both China products only the GM unit is more $$$

The first one that I ate was a genuine GM. It was welded and saw limited use in 2010 (3 hooks or so) and more limited use in 2011 with 3 hooks and some track time. It failed by leaking and nothing spun. Bearings just bad.

Fail #2 was a Delco pump as that is what we had on the shelf. It was welded and made it one day more or less. The impeller spins freely on the shaft now. So freely you could blow it like a pinwheel...

 

[blackdirtymax]

I can't say as that they are different AC Delco versus Genuine GM. Both China products only the GM unit is more $$$

The first one that I ate was a genuine GM. It was welded and saw limited use in 2010 (3 hooks or so) and more limited use in 2011 with 3 hooks and some track time. It failed by leaking and nothing spun. Bearings just bad.

Fail #2 was a Delco pump as that is what we had on the shelf. It was welded and made it one day more or less. The impeller spins freely on the shaft now. So freely you could blow it like a pinwheel...

Are you disassembling the pumps before modifications ?


Built motor , duel fuelers , 60's overs , gtx4202r

 

[blackdirtymax]

I was told it could not be welded and made to hold because of the difference in metals


Built motor , duel fuelers , 60's overs , gtx4202r

 

[Kennedy Diesel]

Are you disassembling the pumps before modifications ?

No leaving the press fit untouched.

 

[Kennedy Diesel]

shipping pump out today.

Awesome thanks!