Replacement Water Pump

[Opelotus]

I finally took the time to compare my old remanufactured water pump (which I just removed from the car) with the new remanufactured unit and realized that their dimensions are not quite the same. The drive pulley on the new pump is recessed 1/16" deeper than the old pump, and the impeller on the new pump sticks out 1/16" more than the old pump. The new pump has a different style impeller with thicker, longer blades. It's impeller also does not sit flush with the engine side of the pump as the old one does. Can anyone tell me what the effects of these differences might be? Will the new pump cause the timing belt to not track straight? Or can I not draw any conclusions from this analysis because both pumps are remanufactured (from different companies possibly). I think the new pump came from 928 International.

[MPDano]

Did you lie them both next to each other on a flat surface and compared the pulley then?

[Opelotus]

no, I just took measurements from the back of the pump to the top of the impeller and from the shorter screw-post to the outer edge of the pulley (seen in pictures)

[Mrmerlin]

my suggestion return that pump and buy a new Laso from Roger

[Opelotus]

Not sure if I can return the pump, it was included with the car when I bought it ~9 months ago. Does anyone have the dimensions of one of the new pumps?

[MPDano]

Wouldn't hurt to ask if it's 928 Intl for a refund. You never know, maybe store credit? I also got mine from 928 Intl but never bothered to compare. So far mines been holding up and no tracking issues.

[mr928]

Sorry but I don't think that pump came from us. We have not sold rebuilt pumps for quite a while plus the ones we sold did not look like that. The one you removed off your car does look like one of ours.
Mark Anderson
928 International

[Opelotus]

Oops, my mistake mr928, I just checked the reciept that the PO gave me, it's from 928 Specialists. Sorry about the confusion!

Does anyone have a "new" pump that they can measure to see if the pulley is flush with the shorter threaded post (just up and to the right of the pulley as viewed from the front, see pictures) or below it? Since both pumps are remanufactured units, I'm not sure which is correct and which isn't, although if the old pump is indeed a 928 Intl unit as mr928 says, then I'll bet it is correct. IIRC the timing belt was tracking just fine in the center of the cam gears with the old pump installed. Would 1/16" pulley offset cause a problem?

[bwmac]

Ok since my car is still apart i went and checked and took a picture for you.
the pulley is flush with the short bolt stump.

[Opelotus]

Thanks bwmac for the photos. Assuming 1/16" difference will cause belt tracking problems, should I attempt to reposition the pulley on the new pump, or attempt to return/sell it? I believe that 928 Specialists have a $200 core charge since the pump came from them, so worst case I could turn in the old pump and pay an extra $100 for a "new" pump. Any thoughts?

[Danglerb]

If I was in your place I would ask the question again over on Rennlist where the water pump guys are much more active.

My next pump will be one of these.
***WATER PUMP PROBLEM SOLVED- (PICS ADDED)*** - Rennlist Discussion Forums

[Mrmerlin]

I would try to return the pump and get a new part Laso is a good pump and they are new not a rebuild

[lfausty]

5/26/2010 mark robinson wp post (timing belt tracking way off on one pulley) hes not unfamiliar with wp and had a bad time with one, think it was that the reconditoned wp pulley wasnt pressed on enough.

[Landseer]

You probably should to go to rennlist and search for water pump information, similar to the danglerb's suggestion.

You have stumbled upon something that can literally destroy your engine block. That pump, no matter which rebuilder and which distributor it came from likely needs to be discarded and you likely need a new one.

The problem has been recognized, root-cause analyzed and solved (a couple of ways) during the last year by some folks that post there.

Respectfully, once you read other's experiences, I don't think you will still consider changing the press-fit alignment of your pump.

[Opelotus]

Definitely! I would imagine the water pump's impeller would do the most damage if it stuck out too far, it would chew the block to bits. However, even if it did not, I would not want to risk ruining so many brand new and repainted parts if the belt were to shred itself.

I put in a message to 928 Specialists yesterday, probably won't hear back from them until Monday; I am hoping I will still be able to turn my old pump for the core charge of $200 (its been a year since the new unit was purchased) to offset the cost of a new pump, not sure what will become of the newer rebuilt unit.

[Landseer]

Most of us are opting for new pumps and castings these days. I'm not sure what advice the various suppliers are giving and if its consistent. New Laso pump, preferably plastic impeller is my choice. Its about $290 or so outright, no core.

My first two were rebuilds, as was another car that somebody else put a rebuild onto. Those cars are fine now, but I worry. It was 2 years ago and predated the fixes we now have available.

The latest car got a new Laso with metal impeller, it was about $230 with no core required. Not worried about that one. New Laso plastic has just emerged into the marketplace in April or May.


Not sure what you mean by getting money for the core. Presumeably the previous owner of your 928 already exchanged cores, maybe had a third one? and got his refund. Maybe not and you could get the refund.

Its also reasonable to ask for a refund for a questionable rebuild.

[Opelotus]

Yes, I am asking for a refund for the rebuilt pump. If I cannot get a refund, I will simply turn in the old pump (PO bought a rebuilt unit and never installed it, so I have both pumps and can theoretically turn in the old one off the car for the $200 core charge).

[Opelotus]

Agreed. 928 Specialists responded to my email. They said the reman. unit is not there's - the order was cancelled due to a time delay or something. So right now I have no idea where the unit came from, looks like I will have to try and contact the PO, but even then, I don't have a receipt for the purchase.

[Mrmerlin]

if your finding an issue with a rebuilt pump prior to install the vendor should take it back and then pass on the info to his rebuild supplier
I would buy a new Laso pump

[Opelotus]

Thanks everyone for the advice, I just ordered a new Laso pump from Pelican (and a new timing gear flange washer, I bent the old one in the process of pulling the gear). Pump is being shipped 3-day air for $3. Now I need to find where the rebuilt pump came from and see if it can be returned. Hopefully I can get enough money back between the rebuilt and old pumps to cover the cost of the new one.