Water Pump Overhaul

[mick695]

Evening All

I've got my water cooled Norton in the shed for the winter to catch up on a few little jobs that need doing and a general tidy up...

Since I bought the bike, I've put approx 5,000 miles on it and the water pump has given no problems and the cooling system is working fine. I've no idea how many miles the previous owner rode since the last time the water pump was touched.

Question is, do I leave well alone or is it worth taking a look and see how things are doing behind the cover.... I'm a great believer in not fixing if it ain't broke, but I also like keeping on top of servicing too...

Another question, if I do take a look at the pump, is possible to check out if the seal is the original size or has been machined to take the larger size without too much dismantling?

Looking for advice, recommendations or opinions...

Cheers

Mick

[tim harrison]

The problem is that unless you check you won't know how worn it is. When the Oldham coupling goes it does so without warning and you can't carry on. The overhaul is relatively straightforward, full instructions are on the Startright website. The most critical thing is to ensure that the coupling fully conects across its faces, both no end play and too much equals excessive wear.

[Anthony Duffield]

Mick,

I was once told to overhaul the pump every 6k miles, so this is what I do, my pump uses the original size seal, I will post the size and also the size of the modified type so when you get the pump apart you will know what you have.

Tim is right about the oldham coupling, I use black molly grease.

I will get back to you re the seal ASAP

Tony

[Anthony Duffield]

Mick,

The OD of the stationary part of the original seal, the part that is a push fit into the pump casing, is 28.6mm

The new size seal stationary part is 30.0mm

The original size seal is available from Ferrier Pumps Aberdeen branch "https://www.ferrierpumps.co.uk/contact" ask for John Ure

Regards
Tony

[Anthony Duffield]

Forgot to provide the original seal type

700, 0127, BVPFF

[mick695]

Cheers Lads

Looks like the body of opinion is that an overhaul is worth doing.... so thats what I'll do... would be rude to ignore good advice

Mick

[mick695]

Hi Anthony

I've received the seal from Ferrier Pumps and a new overhaul kit from Startright.... just wondering I'm missing something here?

The seal appears to be a two piece item and although the outside diameter is the correct size for the casing, the internal diameter for the shaft is at least 2mm oversize...

The box for the seal has the part number you suggested, but I'm just wondering if they have supplied the wrong contents, any ideas???

Cheers

Mick

[Anthony Duffield]

Mick,

The seal I use from Ferriers' is a 2 part seal, stationary part carbon face rotating part ceramic face

I'm assuming you have the pump on your bench and have fitted new bearings and a new lip seal.

Ensuring everything is clean, fit the stationary part into the pump housing using a good quality silicon sealant, if you do not it will leak

Before fitting the rotating part set the impeller clearance using the shims you found when you disassembled the pump, to 1.0mm

Remove the impeller, and carefully place the rotating part on the stationary part (ceramic face to carbon face) and line it up, fit the impeller and tighten the nylock nut, I place a big screw driver in the vice and line up the drive end slot so that I can fully tighten the nut, recheck the impeller clearance, check that the rotating part is still lined up and you will be ready to fit the pump back on the engine.

Tony

[mick695]

Hi Tony

Thanks for your reply, I've been doing a bit of reading up on the seals and your message confirms what I've seen.... everyday is a school day with old bikes...

Anyway, the pump is all back together and fitted to the bike... I started her up this evening and all appears to be well, I'll do some road testing, but I've still got a couple of other jobs to complete first....

Not sure I've made any difference as the pump was working well before and there appeared to be little wear on the couplings... but now I know its all greased up and ready to go.... thanks for the advice

Cheers

Mick