Water pump replacement DIY

vantaam5 · 8th April 2010, 14:06

Gents,thought I do a fast write up on replacing the water pump.
As usual,I am not liable if you mess up during replacement.....

This requires that the t-stat is removed,so follow the instructions here on the board to remove it.
Remove the fan from the water pump(32mm open end spanner,counter clockwise thread)

First follow the instructions to remove the t-stat.
Next remove the drive belts(15mm spanner on the tensioner pulleys,turn clockwise to release tension).
Turn the engine on the crank pulley(32mm nut) until the hole in the vibration damper matches with the hole in the indicator on the block,use a 8mm drill to block the vibration damper.
After that,remove the bolts from the pulley of the crank(13mm socket,tightening torque:25NM).Then use a Torx E14 to remove the bolts of the vibration damper(important:use new bolts for assembly.tightening torque:60NM,2 times 50° torque angle).
Remove the vibration damper(notice for assembly to put it back in correct position,there is only one position how it fits).
Remove the hose from the waterpump housing,a bucket is quite handy underneath as still some coolant comes out..
Unbolt waterpump(10mm socket,tightening torque:10NM) and remove it(hold the tube that you see in the second pic in the top let corner with the green O-ring when you pull the pump out,if it slips out in the back,you have a problem!).Also change the O-ring on the mentioned tube.
Change the pulley(hint:buy also a new pulley,they cost about 20$ and have the tendency to break while changing) from the old waterpump to the new one(10NM for the M6 bolts),use new gasket for waterpump and new O-ring for the watertube.Clean gasket surface on block.
Bolt everything back together,fill with coolant,bleed it and check for leaks!

And get the usual beer to celebrate...

__________________
Part numbers:

1x Water pump : 11511407806
1x Gasket waterpump : 11511406765
4x Torx bolt for vibration damper: 11231402618
1x Pulley for waterpump(optional): 11511406933
1x O-ring for waterpump : 11531710055

Plus the O-rings for the t-stat:

4x O-ring : 11531406249
2x O-ring : 11531407002

and maybe some spares of the O-ring if they break during install...

Also about 3 liters coolant fluid.

Javacore99 · 8th April 2010, 15:25

Good writeup Vantaam.. Been looking for a DIY for waterpump since like forever.. def more work than the thermostat but i will be doing this next month. I have done waterpump b/4 but not on the M5.. Should be fun..

vantaam5 · 8th April 2010, 15:28

Is a bit more work than changing the t-stat,but not that bad.
First time might take between 3-5 hours I think...

If you have any issues while changing,post them.'
Will try to help you then.

Just a short note that came up my mind:

There are no aftermarket water pumps available,AFAIK.
The only way to get them is from the dealership.

The problem is that due to the mass of the fan,the water pump seal starts leaking or the bearing in the pump starts making noises.
Without the stupid fan connected to it,I bet they would last forever.

hawkster01 · 8th April 2010, 17:40

Nice write up on the change out of the water pump. I wish this thread came about a week earlier, I just took mine in to have this done. I was reading an article on preventive maintenance. This was one is highly suggested to take care if you have 60,000 plus. I guess the damage can be pretty devestating if your pump goes. I looked all over for a water pump and like you said no one carries them except the dealers. Thanks again

AMP · 9th April 2010, 00:43

Quote:

Originally Posted by vantaam5

The problem is that due to the mass of the fan,the water pump seal starts leaking or the bearing in the pump starts making noises.
Without the stupid fan connected to it,I bet they would last forever.

Nah.... without the fan then they could make the pump _less_ sturdy, still charge the same amount, and still have it fail at inconvenient times

According to WorldPac there is an aftermarket pump from LASO which is listed as "Under Development." (which usually means, "don't hold your breath.") Still supposed to cost a small fortune so I would prefer the dealer part.

android604 · 9th April 2010, 09:38

The write up is bang on. Followed it last weekend when Vantaam helped me through my pump change.

I also recommend changing the pulley - its plastic, and you will probably have cracks.

Thumbs up - excellent write up, great maintanence.

CarbonCopy · 10th April 2010, 00:10

How do you go about bleeding the system? I haven't looked recently but is there a bleed screw somewhere or do you just crack the cap on the overflow reservoir? I assume you also do this nose-up....

vantaam5 · 10th April 2010, 00:16

No bleeding screw on the S62.
I do it like that:

-car on the ground,fill water up,let it run,top up till marking,close cap and heater full hot,blower full speed.
-run with reving up to 3k once it has a bit temp every now and then,hold 3k for about 20 sec when full warm,done.

-level check and refill when car is fully cold!

No issues for many.many times I did that on S62s......

CarbonCopy · 10th April 2010, 00:25

Thanks! Maybe it is sort of self-bleeding like the days of the venerable M30. I ask however since I think the M50, M52 and maybe M54s had issues of getting air entrapment if not fully bleed. I can't remember if this was near the firewall cylinders. This could create a chance of overheating part of the head and then cracking it. Needless to say I became quite anal about my procedure in recent years....

Blackbird700 · 10th April 2010, 03:56

What was the total time it took you to complete the job from start to finish ? Please forgive me if this is a repeat question to your thread.