Hi,

I have dismantled my MC21 engine ready for the bottom case to be welded, and then a full rebuild.

Naively, I did not undo/remove the water pump impeller whilst the engine was still together, so I now have the impeller and shaft assembly still fitted in the RH case, which need to go off for vapour blasting.

I am now struggling to undo/remove the impeller from the shaft. It does not want to unscrew, and due to the issues with replacing the shaft and the plastic gear, i am being extra careful not to damage anything.

Am i right in thinking that the impeller should just unscrew from the shaft itself.

I looks like it should on the parts diagram, and checking the torque setting on the manual (1 kg-m), it should come undone pretty easily but isn't.

Any ideas?

Many thanks,
Max

Max, I am assuming you removed the impeller from the shaft? That should allow the shaft to come out the other side as it just slides into the bearings that are pressed into the case. If the shaft is stuck in the bearings, you can give the shaft a light tap with a rubber hammer to help break the possible corrosion holding it in place.

if you are unable to get the impeller off, then you will need to hold the shaft (generally the drive gear would have been enough. The impeller doesn't use much torque to tighten it, but it is usually installed with thread lock.

cgallant wrote:
if you are unable to get the impeller off, then you will need to hold the shaft (generally the drive gear would have been enough. The impeller doesn't use much torque to tighten it, but it is usually installed with thread lock.

Thanks for the reply.

You're right, it had been 'secured' with an unholy amount of thread lock.

Some soft jaws in the vice and tiny blast on the impact gun had it off with everything undamaged - phew!

Thanks again,
Max

Evening All.

I am afraid this impeller assembly is still giving me a bit of trouble...

Now the impeller, shaft and bearing are free from the RH case, i am struggling to remove the seal.

The parts diagram refers to the 'Mechanical Water Pump Seal - 19217-KV3-831' but i cannot seem to remove it from the case.

Again, i am trying not to damage the part left in the case moulding as it does not look too worn, so not whacking it too hard - yet!

However, I assume from the parts diagram that the 'Water Pump Seal - 19217-KV3-831' come as one complete part, and the current used part will go in the bin? If so, it doesn't matter if i give it some welly?

Pics below for reference.

Any advice please guys, as i am really nee to get these parts off for blasting so i can start getting things back together?

Thanks as always.
M

The remainder of the seal assembly that is left in the case (the shinier bit):
[img][/img]

The part removed from the seal:
[img][/img]

Where it sits in the shaft assembly:
[img][/img]

Evening all,

A decent amount of views of this thread, but no answers makes me think i may have asked a silly question?

Please feel free to tell me if i have - i wont be offended.

I am a bit stumped though.

Sorry to bump the thread, but this is the last thing to resolve before i can get my cases vapour blasted and start the fun re-assembly bit.

Cheers,
Max

Hi Max
When I change them I heat the case to about 120c in the oven (make sure its clean of oil and the missus is out first) support the case in the water pump area nd tap it out from the inside. There is a rubber seal behind the metal case which you have to force out of the way when you do this.

The metal case is very thin and pretty much impossible to remove without damaging it though so will definetely need replacing along with the rubber seal.

paul g wrote:Hi Max
When I change them I heat the case to about 120c in the oven (make sure its clean of oil and the missus is out first) support the case in the water pump area nd tap it out from the inside. There is a rubber seal behind the metal case which you have to force out of the way when you do this.

The metal case is very thin and pretty much impossible to remove without damaging it though so will definetely need replacing along with the rubber seal.

Thanks very much for the reply.

That is the route i took in the end - hot air gun and a few hefty 'taps' with a socket drift and it finally gave up the fight.

Thanks again.
Max