Hi all after recently spending nearly £300 on a set of tyres, belt & rollers, brake pads & an oil & filter change the nexus has started to throw yet another wobbly. Last friday I noticed I've now got an oil leak. Oil is coming out of the overflow underneath the water pump. After a brief visit to GLR scooters Steve told me he's never seen the like on any master engine & that the fault is probably the water pump shaft which goes through a little bearing then through a small seal in the engine case. We suspect the bearing is on its way out & is causing the shaft to wobble thus destroying the seal hence oil getting into the water pump housing & coming out of the overflow. I'm tempted to rebuild the engine & put it in something else, what I'm asking is the bike won't be worth much as a whole would it be better to strip it & sell it off in parts?

BenR wrote:Hi all after recently spending nearly £300 on a set of tyres, belt & rollers, brake pads & an oil & filter change the nexus has started to throw yet another wobbly. Last friday I noticed I've now got an oil leak. Oil is coming out of the overflow underneath the water pump. After a brief visit to GLR scooters Steve told me he's never seen the like on any master engine & that the fault is probably the water pump shaft which goes through a little bearing then through a small seal in the engine case. We suspect the bearing is on its way out & is causing the shaft to wobble thus destroying the seal hence oil getting into the water pump housing & coming out of the overflow. I'm tempted to rebuild the engine & put it in something else, what I'm asking is the bike won't be worth much as a whole would it be better to strip it & sell it off in parts?

hi ben looking at http://www.gileraspares.co.uk/spares/ep ... d=77456376" onclick="window.open(this.href);return false;

the DRIVE SHAFT FOR WATER PUMP only has a washer the other end , but you would need
oil seal http://www.gileraspares.co.uk/spares/pa ... d=77456376" onclick="window.open(this.href);return false;

RING PUMP KIT : PIAGGIO http://www.gileraspares.co.uk/spares/pa ... d=77456376" onclick="window.open(this.href);return false;

probably a new gasket , and i think all the above are in a water pump repair kit, if you look closely for £40 delivered if you can get your man to fit and refill coolant and bleed it.. seems a shame at this price to break up a scoot over a failed oil seal

The point is it'll be the second time I've had to pull the motor apart not to mention this little problem has left me right in the shit. I own three vehicles on the road currently & not one of them is any good, had to have two days off work this week because of it & as I'm a contractor I don't get paid. I do have to admit that in the last year I've put 24000miles on the nexus (actually it's probably more like seven months given I didn't ride it from November to April) which is obviously too much.

BenR wrote:The point is it'll be the second time I've had to pull the motor apart not to mention this little problem has left me right in the shit. I own three vehicles on the road currently & not one of them is any good, had to have two days off work this week because of it & as I'm a contractor I don't get paid. I do have to admit that in the last year I've put 24000miles on the nexus (actually it's probably more like seven months given I didn't ride it from November to April) which is obviously too much.

i understand what you mean, doing that kind of mileage, i would have thought a lease vehicle would be more suitable to your task, yet thats another matter, after the fact.
this is not really a big job, a competent mechanic, (your friend in need) could drain the oil, empty coolant from bottom of rad, with the tunnel removed, then working from the side of scoot , do the fix on the water pump assembly, then reverse order of oil and then coolant..

no need to drop the engine or anything, protect your 300 investment, and if need be then sell the scoot for £995 recoup losses and sort some other mode of transport for the big milage... or protect your investment of £300 and will have to spend £40 and do it yourself, do you have the workshop manual, if not PM me your email address and i will attach pdf workshop manual which shows step by step what to do.. as something like below

If noise or loss of liquid at the drain bore of the water pump is discovered, it will be necessary to overhaul
the pump as described in chapter "Flywheel cover".
Proceed to carry out a few preliminary operations as described below:
- Place the scooter on its centre stand and on flat ground.
- Remove the right footrest as described in the «Bodywork» Chapter.
- Remove the muffler to access the flywheel cover, as described in the «Engine» Chapter.
- Empty the cooling system by removing the couplings on the pump cover and the filler plug on the
expansion tank.
Remove the water pump cover as indicated in the
figure by loosening the 6 retaining screws.
- Proceeding as described in chapter "Engine",
partially drain the system and overhaul the pump.
- Refill and drain the system again once after having
repaired the damaged and reinstalled all the
components.
N.B.FOR CHANGING THE COOLANT AND BLEEDING
THE SYSTEM, SEE CHAPTER "COOLING
SYSTEM".
Characteristic
Cooling system
approx. 1.8 litres
hope this helps cheers

i was thinking last night, when i was a cab driver i used to do just over 1000 miles per week , which was normal, so you saying the scoot has done 800 miles per week on my calculations you should have done 5 oil and filter changes and 1 air filter and spark plug change in that time frame and spent most of your day on the scoot

if you have used it and not done this... then things mechanical, generally look after you when you look after them.. my nexus is now at 43000 miles and is running probably better than when new... touch wood i generally track ebay italy and uk for nexus searches and you do get parts breaking from a nexus 500 but to be honest they are the same parts reposted during the last year, so i wouldn`t think breaking the scoot would be a good idea, you would probably sell main parts first, forks, wheels, fuel unit in tank then be stuck with parts all in the shed, just my opinion, but nobody else giving you advise... so

Hi Michael I change the oil & filter every 3000miles. Whenever conducting a minor service I always check the brake pads/discs & replace accordingly the same with the tyres & fork seals. the belt & variator I check every 8000miles. Thankyou for the other post but the water pump is not at fault the bearing inside the crank case is which means splitting the cases to replace it.

BenR wrote:Hi Michael I change the oil & filter every 3000miles. Whenever conducting a minor service I always check the brake pads/discs & replace accordingly the same with the tyres & fork seals. the belt & variator I check every 8000miles. Thankyou for the other post but the water pump is not at fault the bearing inside the crank case is which means splitting the cases to replace it.

sorry to hear mate, you will have to judge yourself, with your own circumstances, and choose ... but ive seen the same used, broken down scoots parts relisted on ebay and ebay italy for the past year, you will get the cherry pickings, then get left with lots of other bits.. i have me fingers crossed it all works out, whether fix and sell or just fix or split the bike for bits.. i have had to sell a few things lately that i would normally not do but aving 4 kids is crippling me would sell the 7 seater before me scoot if i had to hope it all works out mate, by the way, did not mean owt nastily in previous posts

BenR wrote:Hi Michael Thankyou for the other post but the water pump is not at fault the bearing inside the crank case is which means splitting the cases to replace it.

ok im only restarting this post as i have a water pump repair kit to fit as my weep hole is weeping coolant

i have gone over the procedure from the manual and done an extensive search on how to do it... benr the mechanic must have been misinformed as there is no bearing in the crankcase.. the impeller is attached to the pin which is thicker at the other end and a spring is at the other end in the crank case near the stator then a ceramic seal is driven in from the outer side which acts as the oil seal then a rubber seal for the water seal before the impeller goes on, which torques up to the rubber seal, which then is the water seal.. so hopefully when my repair kit comes and when i take the pump cover off then the impeller.... if the pin is ok and shows no wear then i should only have to change the water pump seal (1st seal...) as the ceramic seal wont need doing... unless someone has done one and can give me advise then i will have to go with this thinking... cheers , hope someone posts a reply

Hi Michael

I'm new here but have the same job to do tomorrow as I have oil (possibly also coolant) leaking from the drainage hole on the water pump of my recently purchased Nexus 500. Some helpful fellow put a screw in there to mask the problem so by the time I found out it was too late!!

How did you get on with the job? I've bought the seals which go under/behind the impeller and the i-eing seal for the pump casing. From the research I've done it looks like this should be all I need but I'm replacing the impeller while I'm at it. Plus an oil and filter change as I know coolant has gone somewhere and worried some could have got into the oil.

This Nexus has been very little more than a lot of trouble (expensive trouble) fine so far so I am really hoping I can fix this particular problem by myself as have already spent over £800 on itssince buying it for £960!

Hope yours is ok now.

hi, mine was an easy job as it was just the water pump seal (which the steel shaft goes thr) which needed replacing, on the water pump side, the original was ceramic type, the replacement should be a hardened nylon black type, did not have to change the oil seal side, glad really as this means taking the side casing off as it seats behind, so yes oil out, oil filter off, then the coolant and lastly the casing off ( after the exhaust has come off) should be straight forward, but time consuming.. make sure you dont forget to bleed the coolant (50/50 coolant water mix) if you need the pdf workshop manual Private message me with your email address and i will send you a pdf copy. if not sure how to bleed (the air out)the coolant afterwards just ask. i sadly had to sell my beloved beast, got what i paid for her though, funnily enough if i could have kept both scoots i would have, she was a gem.. it only lasted a week in the dealers before being snapped up which was not a surprise she was faultless and a heap of fun, any questions fire away...