Brake Discs Off Road a bad idea?

"Off road" is very stretched word. Every country has own scenery. But in my experience in mud off roading brake disc pads tend to run twice longer then brake shoes, and every other G localy the same.

I have heard from wood workers that drums are more isolated so they work better. But when mud gots in drum, when harder to get in its harder to get out... It eats faster brake shoes. Also in pure theory disc brakes work better in wet then drum brakes.
 

Hi

The vast majority of MB commercials that are designed for site work all run Drum Brakes

I can remember in the late 90's when Discs became the norm and a few off road trucks had disc spec.

MB had to come up with a modified deflector system (read tin plate) to keep the mud and crap out of the disc and as stated more importantly the caliper

OK these things in the main were driven to do a job by people who also in the main didn't give a monkeys or pay the repair bills but all the same...

All these spec vehicles up to at least last year ran all drum set ups whether 4x2 4x4 6x2 6x4 8x2 or 8x4

Not sure on the latest generation  Actros / Antos / Arocs but assume still Drum...

Having had a look at the Unimog axles and brake set up; no wonder the brakes get clogged up with rocks and muck causing your reported damage. The back plate if fitted is so far from the disc and caliper its self. The problem can be solved if the back plate were more closely mounted. 

My choice would be for disc brakes - reduces the unsprung axle weight.

This a quote from the "Horses mouth", as it were;

"Hi Rakesh 

Thank you for your e-mail, all Unimogs have had disc brakes on all wheels since 
1976.

Unimog brakes are generally very reliable and we do not know of any catastrophic 
failures in an off road situation. 

If you have any further questions we would be happy to advise.

Many thanks"

So you would be looking for a pre 1976 model then.

You did not say what is your off road, rally raid and trofy raid for example are so different. For both you can build G and will be different car.

What is true for trucks not always true for normal cars, what is Gwagen.

Drum brakes are cheaper in theory to make, but in real world I can say my G drum brake repair costs are bigger than disk brakes.

Also as I wrote, drum brakes shoes in muddy off road has twice shorter life then brake pads for disk brakes. And are better for stopping power. Drum brakes can offer better protection from dust and rocks.

But you must find your best way for your project, what ever it is.

Bit OT cause no Mercs, but yes, not good to be on your own. 

https://www.youtube.com/watch?v=f8trkgFX6wI

FWIW, I've had Land rovers since I was 15 (41 now), started with a series 2, then several S3's, all of which were drum braked front & back.

Moved on to 90 & 110's, early ones were drum/disc, then from 300Tdi onwards LR fitted discs all round, and subsequent 90/110's that i've built or tinkered with, I've always fitted discs on the back.

I also do a lot of off roading, used to go laning up in Wales a helluva lot, and now around Wiltshire/salisbury plain area, where there's lots of flint & chalk stones. Have had no problems whatsoever with discs.

can probably count on one hand (bear in mind I'm Wiltshire born & bred, so have 6 fingers...) the amount of stones that have got jammed between the caliper and disc. and these usually pop out with a bit of reversing, or just wear down.

LR do fit stone shields (tin plates, as mentioned above) which may/may not help things... the jury is still out on that one. Most people remove them and bin them, especially when they get rotten, But I'm a firm believer that LR developed them for a reason, so they must do /some/ good.

But I've had no accelerated pad wear when off roading in comparison to drums. The best thing though, is the fact that after every off road session, I don't have to fanny about removing the drums, cleaning the clag out, then readjusting the shoes again... maybe it was a LR thing (and maybe MB drums are uber good) but it was a royal PITA as they would be out of adjustment, or badly worn, when filled with watery mud.  Discs are just fit & forget; self adjusting, no hassles, clean off with one press of the brake pedal to get muck off of the surface.

As soon as someone comes up with a good disc conversion for the back of my 460 I'll be doing that!

anyone....?????

Hello Adrian,

Question to ask is why do you feel the need of disc brakes; true, there are advantages in disc brakes but considering the cost for conversion and use of vehicle - is it worth it? Yes, the conversion is possible but considering your vehicle is now a turbocharged diesel or just inter-cooled diesel the power gain does not ask from your braking that your current set is not designed to cope with.

For the example of the chap who did do the conversion; I believe latter converted back to drum brakes as he was not happy with the disc set up either. 

Save your money for now and live with what you have. My suggestion to you.

AH, I will try to find the thread for you. From memory, it was not detailed enough to instruct the actual work just generalised detail.