6.9 Water Pump Removal

[Styria]

There's been a fair bit of discussion on the M100 site regarding removal and replacement of the above pumps.

Some contributors maintain that it is necessary to remove the crankshaft pulley in order to remove the pump. Others advocate the removal of both pump and the housing it is attached to as one unit. I have found, without fail and each and every time, the pump can be removed without having to touch the other two components. Sure, it is a VERY close and tight fit as the impeller flange is almost an interference fit in the housing, but it can be done. The most delicate part involves the JUDICIOUS use of force to actually break the gasket seal to free up the pump.One needs to be very careful. Regards Styria

 

[s class]

What would constitute judicious amounts of force in this instance?

 

[Styria]

What would constitute judicious amounts of force in this instance?

Hi S-Class, depending on the type of sealant used, the water pumps can be very stubborn to respond to removal attempts. Looking at the car from the front, one can only use the spout to which the bottom hose is attached to as a means of leverage to break the seal and force it away from the pump housing. I normally use a wedge type of lever to gently put pressure on that spout, and keep on tapping the pump itseld with a wooden or plastic mallett. You only need a slight bit of movement which then enables one to spray Inox or even WD 40, or even oil for that matter, in between the pump body and the water pump housing. At the same time, keep on applying 'gentle' leverage with your wedge type lever. Eventually, it will let go. Regards, Styria

 

[Styria]

Some four to six years ago (please don't quote me !), I did come across a very stubborn pump (housing) that I simply could not get past the crankshaft pulley - try as I might. Removing of the crankshaft pulley requires a good quality, and sturdy puller which I did not possess at the time. Come to think of it, I still don't. It's one of those jobs that really requires a high degree of skill, especially refitting the pulley to the crankshaft. The pulley is located by two or three solid dowels, and it is all too easy to damage the outer surface of he crank and the inner one on the pulley itself. Just gradually levering the pulley onto the crank by means of the large bolt is not always that straightforward of a job. Once you damage the mating surfaces, you are in all sorts of trouble.

As a consequence, I find it easier to remove the pump, complete with the triangular housing as one unit. Seen from the front, the most lower retaining bolt out of four, sits in water and is subject to rust. Removal can be tricky, but it is worth it in the end. Once that Alloy Intermediary jacket is removed (together with pump), one can then high pressure clean the water passages located in the block. It works. 6.9s can be prone to high temperatures on hot days, and having clean ports, can certainly make a difference. Regards Styria

 

[Styria]

Some four to six years ago (please don't quote me !), I did come across a very stubborn pump (housing) that I simply could not get past the crankshaft pulley - try as I might. Removing of the crankshaft pulley requires a good quality, and sturdy puller which I did not possess at the time. Come to think of it, I still don't. It's one of those jobs that really requires a high degree of skill, especially refitting the pulley to the crankshaft. The pulley is located by two or three solid dowels, and it is all too easy to damage the outer surface of he crank and the inner one on the pulley itself. Just gradually levering the pulley onto the crank by means of the large bolt is not always that straightforward of a job. Once you damage the mating surfaces, you are in all sorts of trouble.

As a consequence, I find it easier to remove the pump, complete with the triangular housing as one unit. Seen from the front, the most lower retaining bolt out of four, sits in water and is subject to rust. Removal can be tricky, but it is worth it in the end. Once that Alloy Intermediary jacket is removed (together with pump), one can then high pressure clean the water passages located in the block. It works. 6.9s can be prone to high temperatures on hot days, and having clean ports, can certainly make a difference. Regards Styria

Apologies for duplicate.