Auxiliary belt

[poseidon]

Hi,

I am not sure about the state of my auxiliary belt since the car is 11 years old. I am going on a long trip.

As I understand the belt failure would be a catastrophic fault since it drives the water pump. My understanding is that the car can not be driven at all with broken belt since engine cooing is not functional without the belt.

What happens if belt fails? Could anyone clarify.

Regards,

Pose.

 

[C220GJS]

You are correct in saying that the engine should not be run without the ancillary belt as the coolant is not circulating and the engine would rapidly overheat.
If you have any doubts change the belt, it takes about 5 mins to replace and is not expensive.

 

[television]

Plus the alternator would not be running and you would have no power steerimg

 

[poseidon]

Thanks Malcolm and George.

I will probabaly consider replacing mine.

I recall that on other makes the water pump is driven by the main belt/chain. This seems more logical considering the importance of water pump. If the auxiliarry belt fails you can still happily drive to home hunderds of miles.

Does anyone understand the advantage of driving water pump from the auxiliarry belt?

Pose

 

[television]

Its much easier to replace an external pump than one that is driven from the chain. Water pumps can and do fail

 

[MotardMan]

If you have any doubts change the belt, it takes about 5 mins to replace and is not expensive.

On a W124 the belt is about £35 for an OEM one. So quite cheap. As for taking 5 mins, blimey, not IME it doesn't. Fan cowl off loosen all the ancillaries, tensioner etc. Spend 20 mins scratching head over "map" of belt routing, spend 20 mins threading and threading the belt, assembly is reverse of removal etc., etc......

Change it if you are in doubt, unless you have access to god quality roadside tools and a standby belt is in the boot.....

 

[Cnics]

Ah the joy of the 2.2 CDi, that REALLY is a 5 minute job and that's if your 17mm socket isn't very good.

 

[poseidon]

Hi,

I have just replaced the belt and the viscous coupling.

The belt replacemnt is 5 min job. Only one 13mm nut. The design of leveraging tightner is brilliant. It can be an easy roadside job.

The viscous coupling is also relatively simple for an amateur. I took off the propeler first (detach from the viscous coupling). When propeler is off the shroud can be removed and there is plenty of space for fighting the tight large nut.

One self satisfied amateur mercedes mechanic this evening.
Regards,
Pose.

 

[kth286]

MotardMan

On the later coupe's it is just a 15mm ring spanner to turn the tensioner a quarter turn. Whilst holding it under tension you can slip the belt off off the most accessible pulley, and let the tension go. Then, as the belt is now slack, just unwind from other pulleys.