Waterpump help please

[marshman]

Ok so I have rebuilt my water pump. New shaft, bearing and ceramic seal from LD Parts, Machined the impeller to give 2mm preload on the seal - ended up with 4.5mm deep recess in impeller. So far so good.

Have just fitted the pump to the block, measured the gap under the cover - 10 thou (ish). Opted for 30 thou gasket to give approx 20 thou running clearance. Then I fitted the new jackshaft - also from LD parts. Now the jackshaft will not rotate - well it will but it is very notchy - the gears are not meshing correctly. Put the old jackshaft in and still the same - thus ruling out a dodgy new jackshaft.

Removed the pump, removed the impeller, and refitted without the impeller to make sure the cage was seated properly, it was, and the gears still won't mesh. Removed pump and fitted the remains of the old pump shaft (I cut it down to use as a mandrel to machine the impeller). This meshes fine with both jackshafts. Finally I played around with the new pump shaft and jackshaft outside of the engine and they do seem to mesh ok. I think the pump shaft is sitting too high.

Question is how can I adjust it??

Should the shaft come flush with the top of the impeller?

Should there be a washer under the Left Hand thread bolt?

Anyone else ever had this problem?

(please don't suggest I scrap it and fit an external pump - tempting though it is). I want the car back on the road for Brands Hatch next weekend.

Any help or suggestions on what to check to find the problem gratefully received.

Roger

[staginhiding]

Something not right somewhere Roger as you are no doubt aware.
Can you get hold of another old water pump just to try it..

it it sounds like something in the modifying process has gone wrong.
Even if it runs slightly off it will ruin the teeth so be careful.
i have never machined one to do the mod so sorry I can't be more helpful

Sam

[staginhiding]

Playing Devils advocate you did fit the jack shaft retaining plate back on the front of the shaft..
Just a thought

[marshman]

Playing Devils advocate you did fit the jack shaft retaining plate back on the front of the shaft..
Just a thought

Hi Sam,
Yes I fitted the retaining plate. The machining for the different seal is only on the impeller -it doesn't affect the shaft at all. Having slept on it I think the shaft is wrong. The height is controlled by the bearing which is effectively located by a circlip so has to be in the correct position on the shaft. The bearing sits in the brass cage. It is possible that it is not sitting correctly at the bottom of the cage. I am going to remove the bearing and shaft and try the shaft on its own.

Would love to just buy a new pump but they are a lot of money Rimmers want £227 - hence the new shaft and rebuild kit - and also I have a deadline for Brands next week.

Roger

[Kevin Garrod]

Roger I have a good used pump which you can have if it gets you on the road.

[marshman]

Thanks Kevin, pm sent.

Roger

[jbuckl]

can you see the waterpump (seal) spring with the pump assembled? (not in the block)

You should be able to.....

If you can post a picture that would be useful.

I have been through this problem a couple of years ago.

I found, after mincing the jackshaft gears, that the water pump seal spring was coil bound.


There are more than one type of seal available.


Some fit old cages (square vent holes) some fit new cages (round vent holes)

Dont rush this job.

The lh bolt does normally have a washer.

What was bad about the 'old' impellor shaft? (corrosion?)

Oh & check the torque to turn with the w/p cover off & l.h. chain off.

[marshman]

can you see the waterpump (seal) spring with the pump assembled? (not in the block)

You should be able to.....

If you can post a picture that would be useful.

I have been through this problem a couple of years ago.

I found, after mincing the jackshaft gears, that the water pump seal spring was coil bound.


There are more than one type of seal available.


Some fit old cages (square vent holes) some fit new cages (round vent holes)

Dont rush this job.

The lh bolt does normally have a washer.

What was bad about the 'old' impellor shaft? (corrosion?)

Oh & check the torque to turn with the w/p cover off & l.h. chain off.

The gear was very worn and had some chipping at the bottom. Distributor drive gear was badly worn as well. So have replaced jackshaft, new distributor drive gear and got a new waterpump shaft. The water pump shaft will not mesh with the jackshaft correctly even on its own. The pics show the reason, the teeth on the new shaft are miles too fat - another example of poor quality new parts.

PICT1000.jpgPICT1005.jpgPICT1006.jpg

Thanks to Kevin I now have a serviceable shaft. I have rebuilt the pump tonight using that shaft and fitted the pump. It rotates OK - seal spring is definitely not coil bound. I machined the impeller to give about 2.5mm of compression - I'm using the "ceramic" seal from LD Parts.

What torque do you reckon you need to turn the jack shaft if it is just driving the pump?

[deanoed]

Hi I've not long done this conversion on my newly rebuilt engine.i stripped mine very carefully and followed the manual up to the ceramic seal And installed it without impeller to make sure it fitted first which it did are you sure the bearing is fitted properly (did you use the more expensive bearing ??

[marshman]

Hi I've not long done this conversion on my newly rebuilt engine.i stripped mine very carefully and followed the manual up to the ceramic seal And installed it without impeller to make sure it fitted first which it did are you sure the bearing is fitted properly (did you use the more expensive bearing ??

Its definatly the gear on the new shaft not correctly machined. I did use the RHP bearing. Its difficult to see how the bearing can be positioned wrong. It fits on the shaft below the circlip and then sits at the bottom of the cage. The top of the shaft was also in the correct place as the clearance measured under the cover was in the range expected. I fitted the rebuilt pump, using the secondhand shaft from Kevins old pump tonight and fitted the cover, all seems sweet now.

[staginhiding]

Good news that all has worked out ok in the end..Worrying though that the new shaft was wrong in the first place..
Can you let me know the supplier by PM as we are not allowed to name and shame..

Good man Kevin by the way..

Sam

[marshman]

Good news that all has worked out ok in the end..Worrying though that the new shaft was wrong in the first place..
Can you let me know the supplier by PM as we are not allowed to name and shame..

Good man Kevin by the way..

Sam

The first line of the first post in this thread says where I got the parts from. REMEMBER IT'S NOT THE SUPPLIER AT FAULT IT IS THE MANUFACTURER! In this case Peter at LDParts did everything possible to resolve the problem and has given a full refund without any hesitation so I have no complaints at all about the service from Peter or LDParts. I am certain that he will be going back to his supplier to resolve the issue. I also think it w ould be unreasonable in this case to have expected any supplier to have spotted the problem with the shaft, I didn't notice anything wrong until I actually fitted it.
Roger

[staginhiding]

Thanks for clearing that up Roger..agreed Peters service is always first class..

Sam

[wilf]

The gear looked to me as if it had missed out on final machining, would have been difficult to spot that "on the shelf".

Poor QC from the manufacturer though.

[jbuckl]

If the spring seal isnt coil bound the unassembled load to turn will be ok.... 4-5 Nm or less I'm guessing.... but I compared to an old pump, it felt about twice as much torque to turn, then spotted the coils were touching on the seal spring.

The teeth in the photo look like they missed everything after the 1st teeth machining operation (hobbing)

The gear was very worn and had some chipping at the bottom. Distributor drive gear was badly worn as well. So have replaced jackshaft, new distributor drive gear and got a new waterpump shaft. The water pump shaft will not mesh with the jackshaft correctly even on its own. The pics show the reason, the teeth on the new shaft are miles too fat - another example of poor quality new parts.

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Thanks to Kevin I now have a serviceable shaft. I have rebuilt the pump tonight using that shaft and fitted the pump. It rotates OK - seal spring is definitely not coil bound. I machined the impeller to give about 2.5mm of compression - I'm using the "ceramic" seal from LD Parts.

What torque do you reckon you need to turn the jack shaft if it is just driving the pump?