I posted this on the end of another thread that seems to have died.

I bought a water pump for my 1990 S4 a while back and haven't got around to fitting it. After reading a recent thread about Laso pumps I decided to dig it out had have a proper look at it. The pump looks like the pictures of the Laso pumps that I have seen, has the plastic propeller and made in germany on the casting. However I notice the part number has been ground off the casting! Anyone have any opinions on why someone would do this?





The pump was bought as a new Laso pump from a reputable specialist in the UK. If I had noticed at the time I would have questioned it but as I say it was a while back now.

 

Plastic impeller and looks like it has the metal bushing insert, sand casting - so this really looks like one of the updated Laso designs. Really odd that the name would be removed.

 

New? The gasket surfaces appear to include remnants of an old gasket, and buffing from using a wheel to remove more. The original surface is a machined finish similar to what we see from Blanchard grinding (big flat wheel).

 

probably was an early style pump where the cast aluminum post which holds the roller got broken off....so the rebuilder machined off the nub drilled and tapped it for the later style screw in pivot. Then to make it less confusing removed the early style part #....Just my guess

 

Looks like a new Laso pump to me - did they sell it as a Laso pump?
Later style - I would ask the seller why they ground off the name.

 

Black market pump

 

my guess is that pump failed tolerance specs due to the marks on the machined gasket surface. other than the gasket surface, it was too good to scrap, so they removed the name and sold it to a reseller. OM could not warranty with those deep cuts in the machined surface.

 

Could it be a rebuilt Laso?

 

Rebuilders are usually pretty good about cleaning the castings thoroughly after disassembly. That gasket face looks like it still has gasket remnants on it or, as Otis suggests, the casting is flawed or not machined completely. I look at the amount of fun needed to swap a water pump, and then decide how lucky I feel with a less-than-stellar example like this. OP says that he's had this one for a while so any recourse to seller is probably long gone.


My car just let me know that it's time for this job again, 40k and at least eight years since it was last apart on the garage worktable. Hooray for me!

 

Ok I had a close look at it in a good light last night. I don't think there is any old gasket on there. From what I can see is it looks like the surface has been machined in a circular motion. It looks like this has been done in at least two different directions i.e. the pump was machined once then turned around and machined again. Depending on how you hold it to the light these show up a dark or light spots. So in the photo above the light/shiny parts are the swirls going in one direction catching the light. The dark parts which I assume is what people think are gasket remains are the swirls coming in the opposite direction.

Feeling the surface with my finger it feels perfectly smooth, even though some of the spots look in the photo like they a quite badly gouged or scraped. As has been suggested by some this pump perhaps failed quality control and the factory sold it on after removing the logo.

Slight dilemma here. Do I install it? The pump seems good and the swirls on the metal seem more visual than actual damage to the surface which feels smooth. Also as I say the pump was bought a while back possibly two years ago. Legally there is no need for the supplier to provide a refund/replacement although they may well do out of good faith.

 

And removed the timing pointer?

There's more to this story....

 

Agreed. Lots not right on this pump.

 

That pump's like a broken condom: Nothing good is going to come from it.

 

this pump looks remarkably like the new Laso pumps that Roger sends me,
they all have the dissimilar machining on the mating surface.
NOTE he real test will be a dry fit to see if the pin holes are tight and need some reaming,
this would indicate the pump has never been fitted
make sure to check that the impeller spins free when dry fitted

 

The timing pointer came as a separate part with the pump. Are they usually pre-installed on the Laso pumps?