Water Pump Woes

[David53]

I am so sick of the crap quality of modern parts! I replaced the water pump on my Series II about 1,000 miles ago with a brand new one from ESM. I have just discovered the rear bearing has worn out and the spindle is quite wobbly. Not too noisy at this stage. I am currently about 100 miles from home so I hope it lasts till I get home. In an emergency could I run with fanbelt removed, or would she overheat? I'm aware very early cars didn't even have a water pump.

[MarkyB]

It will be fine without a fan belt unless you get stuck in traffic for a while.
How tight are you running the fan belt, it shouldn't be bar tight or it will wear the bearings prematurely.

[Neil MG]

I wouldn't run without the fan belt for more than a few minutes at a time. There is no temperature light or gauge so you can easily blow the head gasket. Running without the fan is no problem, but running without the pump will cause rapid overheating. Even more so in a hot climate.

Funnily enough I also changed my pump with an ESM unit (just before you if I remember) and there is a quite a lot of noise from that area. I haven't had a look yet, but I assumed it might be crankshaft pulley or dynamo bearings as the pump is recent. maybe I should check that sooner rather than later...

[David53]

Thanks. Hopefully it will hold out until I get home. The front bearing seems ok but the rear is very worn- quite a bit of movement.

[kennatt]

the ser 11 will NOT run withoot the pump it will very quickly overheat blow your head gasket and very likely seize the engine.As long as its not leaking it should be ok for a while

[MarkyB]

Not such good advice on my part, I was thinking that thermo-syphon was how the series II worked originally.

[David53]

In answer to your question the fan belt is just tight enough to spin it and no more. The series II pump has a hole in the side covered with a screw. I asked ESM if this was to inject grease but was told the modern replacement part did not require lubrication. I now think this was incorrect I will pack the pump with grease through this hole to get me home.

[Neil MG]

I replaced that screw with the grease nipple from the old pump (I just assumed that was the intention).

[David53]

Very embarrassing - now that I have the car home and can get at everything properly I find that the bearings are fine - the pulley was loose on the spindle

The series II Pump has a large shroud type pulley which hides the shaft - it was this pulley that was moving and it wasn't until I got it home that I could see properly. all it needed was a quick nip up of the bolt.

The owners manual says to use 140 oil "sparingly", which is why there is a screw over the hole with sealing washers. I intend to use grease though.

[RobThomas]

The rebuilt MM waterpumps are rebuilt with sealed-for-life bearings and if you pump grease in you will only push the bearings and seals off of their seats, causing a leak. Not sure if srs2 pumps are the same.

BTDT.

[David53]

Thanks Rob. Not sure if they are sealed or not. I pumped in some grease but not until it was packed solid. So I guess if they ARE sealed it won't hurt, and if they are stanjdard bearings they will get greased! That's the theory anyway.

[moggiethouable]

Can I ask fellas is it better to use grease or oil on the water pump?
As a screw is attached for said lubrication I assumed it would be oil, mine is an original water pump with the screwdriver slot screw fitted.

[bmcecosse]

Put in a bit of engine oil - if you pump in grease with a grease gun - you will damage the seals.......

[moggiethouable]

Put in a bit of engine oil - if you pump in grease with a grease gun - you will damage the seals.......

I have just discovered this reply, thanks Roy.

[David53]

Well, the theme of my original post was right! The pulley was loose on the shaft but after tightening it several times and having it work loose again I have pulled the radiator and fan blades/pulley off for a good look. What I have found is that the pulley, once tightened up, is far too close to the pump and is fouling the free rotation of the pulley to the extent that the blades barely turn. I have checked with an old pump and there is far more clearance and the blades spin freely. So the new pump is basically made wrong like so many modern parts put together in India or wherever. I will now get the old one rebuilt and refit it.

[bmcecosse]

Can you not just put in a spacer between pump and pulley ?

[David53]

Yes Roy I am going to try that, but with the 803 pump the pully slides over a woodruff key on the shaft, so a spacer would need to fit in behind that. It would also need to be exactly the right dimensions - 17.5 mm outer and 12.5 mm inner so that it fits exactly over the shaft and doesn't extend past the shaft opening. This is the old pump to give you an idea

[bmcecosse]

With your great skills - that won't be too difficult! Just watch the alignment with the crank pulley and the dynamo.

[David53]

Yes that's another issue! And all because modern part manufacturers can't get their tolerances right....

[David53]

After several attempts using spacers, washers, new bolts and Loctite I was continually having the pulley work loose on the spindle, resulting in a hell of a noise. In desperation this afternoon I ripped out the water pump and replaced with one I had kicking around that (I thought) had worn bearings. Bolted everything back together, took her for a hard blast for 30 minutes down the motorway and on return no leaks, no rattle bearings and above all the pulley was still rock solid

I can only assume the water pump's housing was so badly cast that pulley was rubbing against it and working loose. The old one I refitted seems to be working fine and the is no rubbing

Phew. Now for a cuppa......