Cambelt R129 300sl

[dog]

Fanbelt R129 300sl

I am going to have my fanbelt and tensioner changed on my R129 300sl have you got change the water pump too (so i've been told ).

 

[BTB 500]

It's a chain, not a belt. Does it really need changing?

 

[dog]

It's a chain, not a belt. Does it really need changing?

Sorry i mean fanbelt is re edit

 

[Lyserman]

It is not essential to change the water pump but prudent.

The pump seal will have been subjected to years of use and normally starts to leak just after the belt has been renewed.
So, rather than having to remove the belt twice, it is cheaper to do the job all in one go.
The pump won't be that expensive and will only add 30 minutes to the job.

 

[RichardF]

I've just changed the pump on a 320, when I swapped the drive belt it was "clicking" so I thought it would be prudent. Not sure about the 300 but allow a bit more than an additional 1/2 hr!

Belt tensioner, had to come off, P/S pump moved, coolant flush etc. One of the hex screws on the M104 engine is a mare to get at, clumsily I managed to strip it. Took me 6hrs, start to finish, (inc stripped hex) an experienced mechanic maybe 3 hrs. MB pump was circa £250 Febi pump around £125.

 

[grober]

The M103 [300] engine [single cam] and the M104 [320] engine [twin cam] have very different water pump setups. The 300 is relatively easy.

 

[dog]

Ok thanks all, I can see small cracks in my fanbelt don't know what its going to cost in all with the water pump now and belt and tensioner. better start asking in some garages

 

[RichardF]

Ok thanks all, I can see small cracks in my fanbelt don't know what its going to cost in all with the water pump now and belt and tensioner. better start asking in some garages

My guess £600

 

[bolide]

If the water pump is leaking or if there is excessive play I'd replace it. Otherwise I'd leave it well alone

On a car of that age I don't think preventative maintenance is the best use of resources. There will always be bushes & other rubber parts that would be a better place to spend money than a water pump that isn't leaking

Nick Froome

 

[dog]

If the water pump is leaking or if there is excessive play I'd replace it. Otherwise I'd leave it well alone

On a car of that age I don't think preventative maintenance is the best use of resources. There will always be bushes & other rubber parts that would be a better place to spend money than a water pump that isn't leaking

Nick Froome

Good point