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Thread: Construction of Graf water pump?
03-25-2006 11:42 PM #1
Construction of Graf water pump?
I ordered a Graf w/p from autohausaz.com recently for routine replacement. I've seen articles posted elsewhere that indicated that the impellers were "solid iron" instead of sheet aluminum.
I would describe mine as sheet aluminum spot welded together.
Am I getting something other than what I should be, or is iron no longer offered from Graf?
03-25-2006 11:45 PM #2
03-26-2006 12:20 AM #3
03-26-2006 05:46 AM #4
- Owasso, OK, United StatesMember No: 67006
- Join Date
- Feb 2003
- Rep Power
Geba makes what looks like a cast iron impeller
On the site I buy my parts, they sell both Geba and Graf w/p's. As you have described, Graf's impeller is a light, thin metal. I just replaced one in a '99 323i with M52 engine and the factory unit was just like it--it was not a plastic impeller like I've seen before on most factory w/p's. The Geba unit looks a lot more robust but I've heard that the extra weight from this impeller may wear out the bearing quicker.
I've been using the Graf w/p's with the light metal impellers for about 10 years and I've never had one fail.2003 530i--Sterling Gray/Gray
5-speed, Sport, PP, Xenon, CWP, CDV Delete
03-26-2006 08:35 AM #5
Re: Construction of Graf water pump?
Solid "iron"? Iron isn't good for much at all, much less immersed in water. I don't see any problem OTOH with a spot welded aluminum impeller in an aluminum engine.
When you consider the forces applied to the water pump bearing by weight of the fan assembly and the belt tension, the weight of the impeller becomes mostly irrelevant.
03-26-2006 09:00 AM #6
03-26-2006 11:28 AM #7
I'd not worry
Graf has made it this way for over 15-20 yrs and used qidely in MB, BMW, Audi, Volvo, VW etc.
A picture is here:
(Old WP with plastic impeller shown for comparison)
I have been using Graf for more than 10 yeras in different cars. No issues at all. In fact after 100K miles at removal for leaking seal, the impeller was still good!
03-27-2006 09:54 AM #8
03-27-2006 09:55 AM #9
03-27-2006 01:09 PM #10
03-27-2006 01:14 PM #11
03-27-2006 01:16 PM #12
03-27-2006 01:28 PM #13
03-27-2006 01:39 PM #14
Re: Pictures of my pump and box
Funny, the baseplate, ring, and welds look like stainless, but the impeller looks like aluminium. That combination doesn't sound all that great to me, so I'm probably wrong about the impeller and it's stainless too.
All the nonsense about these water pumps could have been avoided if they'd have used a decent material for the plastic impeller in the first place. Something like glass-filled polysulfone. It's almost as strong as steel, would outlast the car and doesn't cost all that much more than junk plastic. It's just like the morons that make water heaters. Saved $0.04 on the dip tube, and it cost them many millions in settlements when they had to replace them when they decomposed. The better water heaters now have polysulfone dip tubes.
03-27-2006 02:02 PM #15
Graf versus Geba versus Airtex
Well, I agree with Craig, I don't know what to say but Graf WP used to be more solid, now with the "New and Improved" look, it has the look of aircraft propeller. Probably OK.
Graf "New and Improved" looks like they weld many pieces together. So as a rule, anything welded together and submerged in water tends to fail.
However, Geba looks more like one single piece.
Airtex...I do not like Plastic (except for VISA card!).
09-11-2012 03:17 AM #16
Geba Waterpump failed less than 25K miles
I thought to replece my OEM waterpump on my E36 at 60K with the "improved" metal impeller
pump by GEBA. It completely seized snapping the shaft in two stopping the engine completely.
I thought my engine had seized as could not budge the crankshaft with a breaker bar and 22 mm socket.
The bearings on the waterpump had seized resulting in breaking the shaft of the pump.
It seems the extra weight of the metal impeller (i think it cast iron) wore the bearing prematurely.
I put the original pump back in and ordered a HEPU pump with metal impeller. Hopefully this brand that was
OEM for the old 4cyl Volvos is excellent quality...
09-11-2012 12:34 PM #17
09-13-2012 04:13 PM #18
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