M40 water pump.

Post Sat Jan 12, 2013 2:57 pm

So it looks like I need a new water pump.
So far I have removed the cowling, drive belt
and all four bolts from part No 5 below.

http://www.realoem.com/bmw/showparts.do ... g=11&fg=35

The pulley refuses to come off. Have given it a few slaps but still
no joy. I s there a knack to this, or do I need to increase the
velocity of said slaps ?

TIA.

Post Sat Jan 12, 2013 3:06 pm

Yes.

Once the pulley agrees to seperation,you will be able to access two blank,threaded lugs,that enable you to screw

two bolts in to help extract the pump.

Post Sat Jan 12, 2013 3:20 pm

Cheers Malc, thought that might be the case.

Post Thu Jan 17, 2013 4:19 pm

Right, after a bit of effort , I have managed to remove (most) of the water pump.

However part of the back of the pump remains stuck fast in the block.
Photos of majority of pump removed and hopefully showing what remains
inside the block.

Don,t see what other option I have other than to stuff some rag or paper
at the rear of the pump, to stop any bits of metal entering the block, and take a chisel to remains of the pump.

Unless any body can come up with an alternative.
TIA.

Post Thu Jan 17, 2013 6:20 pm

Thats unfortunate, I look forward to see what the recommended action is...

Post Thu Jan 17, 2013 8:58 pm

My last e30 did the same, block off and chisel out gently if u hit the smooth metal where the pump fits it will crack and leak unless filled with something like quick steel or liquid metal. Good luck hope it helps!

Post Thu Jan 17, 2013 9:02 pm

Forgot to add soak in wd40 to help ease it out, don't think the impeller part at the back of the old part will fall backwards as is a half moon hole from memory, again good luck!

Post Thu Jan 17, 2013 9:07 pm

On it tomorrow.
Will let you know the result.

Post Thu Jan 17, 2013 10:16 pm

Old pump looked really corroded so maybe a good idea to soak in wd40 overnight, it looks like alloy metal pump which is soft compared to the iron block/steel lined hole but corrosion fuses it like shit to blanket

Post Sat Jan 19, 2013 11:46 am

Parts arrived today....... but the gasket is massively over sized.

Worst part is I,m transportless untill this is fixed.
Touring is in my works Depot, 2 miles away and the nearest parts factor another mile
from there. Luckily I stored all the tools I need at the depot.

Right PITA this is turning out.

Edit, my apologies, sounded like a whinging brat there.

Post Sat Jan 19, 2013 1:52 pm

Argh!

Thats annoying, I feel for you mate, have you phoned the company? They might be able to provide a very quick delivery of a new pump?

Post Sat Jan 19, 2013 1:56 pm

M40 water pump doesn't use a gasket. Seal is by an O ring.

Post Sat Jan 19, 2013 2:07 pm

Brianmoooore wrote:M40 water pump doesn't use a gasket. Seal is by an O ring.

Thanks Brian.

So why do ECP show a gasket on the page for m40 waterpumps

http://www.eurocarparts.com/ecp/c/BMW_3 ... 6a6&000601

Post Sat Jan 19, 2013 3:20 pm

Indeed. That looks like an M20 pump gasket. Just clean out the block and smear some grease on the pump, and slide it in. M40 pumps always seem to break up in the block if they've been in there a while. Later ones were fractionally slimmer and weren't such a tight fit in the block. Hammer and a wood chisel to break up the remains, and fish the bits out.

Post Sat Jan 19, 2013 5:08 pm

Brianmoooore wrote:M40 water pump doesn't use a gasket. Seal is by an O ring.

Oh Yea, Doe! Should have know that!

Post Sat Jan 19, 2013 6:00 pm

Good bit is that the block is iron and the pump(deceased remains of)alloy,so it will give with effort and plenty of swearing.
difficult to be certain that all the old pump is out,but capture as much as possible.

The very worst case senario is that M40's are in plentyfull supply for not very much beer money.