Changing the water pump on a 500SEC

[adamb]

I've spent some time today disassembling the items required to replace the water pump on this '84 model. I seem to have come unstuck at the lowermost bolt. While I've managed to unscrew it, the bolt is long and according to the manual requires the removal of the vibration damper. This has made a relatively simple weekend job into something of an ordeal. The damper has a detent but it seems too shallow to let the bolt come out.

Frustratingly, the instructions for replacing the waterpump don't talk of needing to remove the radiator yet removal of the damper does require the radiator to be removed.

In short, I need some advice. Is it worth proceeding in a home mechanic set-up, and if so, I need some help on what to do next.

Thanks,
Adam

[s class]

I'm not familiar with that engine, but I bet RonB over at M-100.cc would know the answer to your question.  My feeling is, you probably can do it at home, but it may be a bit time consuming.  I hope for your sake you don't need to remove the damper, as that will require locking the ring gear, and releasing the bolt on the front of the crank.  Do you have the pulley cone off?  I assume it is a separate item bolted onto the damper?

[adamb]

Thanks for your reply. I don't really wish to remove the damper because that makes this job rather nasty. The pulley cone is still on an doesn't need to come off as it's not blocking anything in itself.

[TJ 450]

For water pump removal, the vibration damper must be removed in my experience. This is quite straightforward on these engines, as it is simply held on a hub by the pulley bolts. All you need to do is undo the pulley and you should be able to pull the damper by hand. This exposes the remaining bolt(s) on the water pump.

This applies to all M116 and M117 engines, whether alloy or cast iron blocks. It's an absolute piece of cake compared to the M100/M110 engines and a totally different setup.

You will probably need a deep wall 13mm socket for those pulley bolts, however.

You are correct in saying that the radiator needs to be removed, as you will need to access the pulley bolts through the aperture.

Tim

[adamb]

TJ, so you are saying there's no need to do the hub nut that's attached to the crank? And just the 6 retaining bolts will do?

[TJ 450]

Yes, just the retaining bolts, but there isn't much clearance from memory.

Tim