CLK Alternator - life of brushes?

[jimsinessex]

1999 CLK 230K, bought new and now at 100k. I now do 30k a year and am considering areas that might cause avoidable breakdowns. What have been others' experiences with alternator life, particularly the brushes? The item fitted is a Valeo and is giving no problems at present. Am I worrying unnecessarily?
It has been suggested that if brushes on the Valeo wear out then the shaft contact surfaces will be worn badly as well.
I would also be interested in other owners' experiences generally with high mileage CLKs, what are other avoidable breakdown areas?

 

[Arnie]

I'd worry about it when it comes to it. I think that at 100k miles, it should not be a problem. It's a lot of hassle to take the alternator out and you might as well do it only when you need to. Reconditioned exchange units are not expensive.

More importantly, perhaps, check the drive belt.

 

[jimsinessex]

Arnie, thanks for that.

What is the particular hassle you refer to with removing the alternator, the one area I am a bit concerned about is releasing the tensioner and then relocating the belt back into position - any tips?

You have also hit on another potential trouble area that I was thinking about - the PolyVBelts. What is the experience with the life of these (two on the Kompressor models), is visual inspection sufficient or is there a mileage when they are prone to failure. The Kompressor/Alternator drive belt is very difficult to check visually anyway.

Cheers, Jim

 

[landover]

I would not worry about the alternator .I would change the belts .I recon they will fail first .

 

[Arnie]

The hassle is the belt tensioner, which on some MB engines is hard to undo and also extracting the belt is sometimes tricky without removing radioator baffles etc.

The belts are normally good for at least 60,000 miles (or 5 years), but they tend to age and the rubber then starts to show little cracks. This does not necessarily mean that it will fail, as there is a tough polyester cord beneath, but it is an indication that a change is probably in order.

Once the belt is off the alternator is not too much trouble, if you want to give that a service.