280i Waterpump seal.

[andychalkley]

Hi

I have water in my gear oil. I have the water pump out. I think the bike is 2013. There is a circlip behind the drive gear which was tricky to remove. It was suggested that I change the pump seal, although the problem could be somewhere else.

How do I remove the impeller?

Does anyone know the seal part number?

Is the seal a common part?

Thanks in advance.

Andy Chalkley

[canada280i]

They are not meant to come apart which is why you are having difficulty removing the circlip. The gear is a press fit on the shaft, you may be able to remove it by heating the gear and prying it off but be careful. When the were around ossa only sold the water pump as a single unit, you could not buy just the seal. I had an issue with one once that had to be replaced so I took the old one apart with brute force which is how I found out about the press on gear. I bought a couple of spares after that just in case

[canada280i]

What year is your bike? Where does the crank vent cone out of the case?

[andychalkley]

Mmmm. It seems a bit fragile. Do I put a worm drive clip around it to hold it or something?

I used force to get it out until I saw the big circlip. It needs a pair of circlip pliers with the tip bent to a silly angle. The seal is 10mm x 35mm x W7mm. I shall try the bearing supplier first. The impeller is some mildly flexible black plastic. It is all beautifully made. If I  have damaged anything, I should be able to Araldite the impeller to the shaft. Even if I need to modify the impeller hole. I think it is 2012, 2013 or 2014. My eyes don't read the small writing too well. I'm good on logic but poor on memory.

Water in the oil may be from somewhere else. I just thought it was the first stop to change a seal.

Out of interest, there was some black muck inside which surprised me as it has always had 100% Tectaloy inhibitor in the system. The aluminum also had a black tinge in places. I'll try the waterless coolant in future.

The shaft runs in a single bushing on one end and there seems to be no provision for end-float or restriction of shaft movement laterally. It is almost as if the seal itself provides some restriction on movement.

[ossabc63]

Hello i was told by the ossa importer in canada that ossa pumps use a single lip seal and they made up a jig to go behind the drive gear to press off the gear. Then replace the seal with a double lip gasgas seal which is the same size as long as the shaft is not to grooved. Not sure if you would heat the gear in a toaster oven and pump in the freezer to put together cheers. 

[canada280i]

Black muck could be the ends of the impeller rubbing on the outer housing

[andychalkley]

I now have it repaired. The procedure for anyone else:

The gearwheel needs to be removed with some sort of puller. It is not too tight so some flat aluminium behind the gear will be plenty. Some taps with a hammer and a block of wood would also remove the gear provided the gear was supported. A puller is the best option. The large circlip can then be removed. The large circlip is close to impossible to remove until the gear wheel is removed. Circlip pliers with an unusual bend might do it. The seal is 10mm x 35mm x W7mm. This is a standard size seal but may not be commonly stocked. Reassembly is obvious. There are design issues here: The shaft runs in a single bushing in the crankcase and is perhaps encouraged to float by the seal. The bushing has no entry or exit for splashed oil. Thus, purge of wear debris is perhaps prevented. I wondered about drilling a small hole on the top to allow oil to run into the bush. It is difficult to test the state of wear of the bush. Also, when oil is put into the bush for reassembly, it creates an airlock as the shaft acts as a piston which impedes assembly. It is difficult to detect whether excessive force is being used during mounting of the pump. Another issue is that the seal runs directly on the shaft. Thus a slight groove may occur in the shaft.

I initially tried Evans waterless coolant. I reverted to green coolant. I had two concerns:

If coolant gets into the gear oil, we detect a change in gear oil colour. I'm not sure if this is the case with waterless coolant. Secondly, if the engine gets too hot she boils and we use the boiling as a measure of: "She got a bit hot." If the waterless coolant does not boil, we cannot tell if the engine is overheating as we have no temperature monitoring in place.

There appears to be no provision or space to add a second seal and run excess water to the atmosphere. From memory, I did this on some early Shercos. I fitted two seals and Araldited some very small bore aluminium tube from the model shop to vent escaping water to the outside world where it could be seen. (On the Ossa, I have the radiator vent pipe slightly outside so that I can see any water dribbles.) 

The main problem is the large circlip hidden behind the gear wheel. Seals normally retain their position with their interference fit. I can't see that pressure build-up would be enough to move the seal. Mine now runs without the circlip. I have previously used Tectaloy concentrate and did not bother to add water. But some water may be useful to allow it to boil when too hot. I never really thought about it before.

Hope that helps. Andy Chalkley 

[lotus54]

I have one of the Xiu electric water pump kits I am planning on installing on my old (now sold) OSSA Explorer.  It is getting coolant in the gearbox and blowing on one side and plugging other of the plump showed a leak internally.

https://www.xiu-rdi.eu/comprar/36/kit-basico-de-bomba-de-agua-electrica.html

  Since it is not my bike, I would rather just install this pump. Especially since I had bought it when I owned the bike, and the pumps are readily avaliable. Plus any leak will be obvious and not into the gearbox.

Has anyone installed one of these?   If someone has, I would certainly like to see where you mounted and the hoses you used.

   I don’t see anyone that still has original pumps anymore. I would rather install something I know will not leak, since it is not mine anymore. He has already had more issues than I did the whole time I owned it. (Failed temp sensor, causing overheating, which I think caused blown head ‘O’ ring).

 

thanks
mark

 

[peterb]

Later model Ossa water pumps came with a stop to prevent end float of the shaft, unsure of the year. Earlier models as described had nothing to prevent shaft end float and in some cases, the movement caused the impellor to rub against the housing creating a grey sludgey mess in the cooling system. The GG water pump dual lipped seal fits straight in. Pretty sure the Xiu electric water pump is identical to the standard issue Vertigo unit, which have been quite reliable with no chance of coolant leaking past the shaft due to a non mechanical drive to the impellor. Bye, Peter B.

[lotus54]

Yes, I think it is the same pump Vertigo uses.

    The pump works well and seemed to fit in this spot with a guard.  Not many places to put it- and I’ve never seen one done.

For the upper hose, I used one off a KTM that was connected to ‘splitter’.  Fit quite well.  I originally was going to mount it inverted, but it seemed to pump way better this way.

[lotus54]

The the pump not yet mounted up or clamps on yet. 

 

 

[Saulus]

Hi guys, i have the same issue with the leaking waterpump. Now its disassembled and im searching for a fitting shaftseal but i couldnt find anything. Does anyone know where to get them?

The seal is 10mm x 35mm x W7mm

Thanks

[ossa68]

https://www.ebay.it/itm/GasGas-310018-Paraolio-pompa-acqua-10x35x7/372649303663?hash=item56c3a11e6f:g:TdoAAOSwyO1cmvvS