Air Disc Brakes

We ordered a 4 Axle Transfer Trailer with Disc Brakes. It is more expensive about $1200 per Axle right now and a special order. Take delivery in 2 weeks and will post results compared to S cam system.
You save 6 grease points per axle, so in our case thats 24 points less on the auto greaser and saves us about $1800. I saw them put on the trailer and they look easy to service if you want to change pads. But if a wheel seal goes the caliper would have to come off, a little bit more work!

 

Don't get me wrong, I really like the idea and I will have air-disc on the front axle (only) on a KW I will have on the road before long, so I can't offer 1st-hand experience yet.

One thing I do is to spec the larger drums on the drive and trailer axles (16.5 x 8.625); opionions and stopping tests seem to show larger drums aren't far behind the stopping capability of discs, except in repeated brake applications (mountainous terrain) where the heat-rejecting properties of discs are superior.

I will share what a very knowledgeable young woman with KW Applications Engineering and also regional service experience told me a few years ago about one downside of discs - just what you brought up, running off-road and the possibility of small stones being caught in the caliper and cutting into the rotor. I have no idea if that is a real issue or just some remote possiblily.

Just a few months ago I was talking with someone a Hendrickson Trailer and they shared their thoughts on discs on the trailer - "not there yet" was the comment. I know this fellow mentioned warranty that was less on disc components than on drum set-up, not sure if there were issues other than that.

You may want to question some people at the truck and trailer builders as to their thoughts. Of course, everyone has an opinion and it may not be correct! Once again, at some point I believe discs will overcome drums in popularity, either by way of operational advantages or by being mandated through better stopping distance.

 

i don't have any experience with disk breaks on a semi, however i will comment that offroad you will get rocks in drum breaks and they can gouge the drums up pretty bad.

 

Same here, I talked to my local Utility dealership shop manager who used to be active engineer and worked at Utah factory and he said exact same thing he said year ago - discs are not recommended on trailers, not by him

 

I have pulled a few different trailers with discs and they are definatly a better braking system than drums . They come on more even and feel more controlled, especially when empty. I really like them and notice a big difference when I go back to a drum brake trailer after pulling a new disc one around for a few weeks.
I don't know much about the service and maintenance of them though as they are leased trailers . And I have no experience with discs on a tractor, only on trailers.

 

We are using discs in Europe since the mid nineties , abs was phased out around '98 or so in favor of EBS , combined with discs the effect was dramatic, Mercedes was the first to have them and had to put warning signs on the back of their trucks cos their brakes were so much better than everyone else's at the time, this is a Volvo anti colision system video but you can see how effective disc brakes and EBS are

http://www.youtube.com/watch?v=ridS396W2BY&feature=youtube_gdata_player

Discs are cheaper and easier to maintain , just be careful of the calipers that are fitted, some have a tiny adjustment screw, small adjustment screws can break thus the whole caliper needs to be replaced, spec a brand with a large adjustment bolt. other than that they are trouble free and pads can be changed in 5 minutes.

Discs are not ideal for dump truck or offroad, deep mud and sand can cause premature wear on pads and excessive heat then driving through cold water can crack the discs but for highway use they are a must!

 

Also I should say that because Europe is 99% discs drum brakes are now actually more expensive to spec

 

i was looking last week for brakes for my 4axle mercedes tipper


crap quality , 410x213mm(16.14"x8.38") front drums , and 410x270mm(16.14"x10.63") rear drums and brake liners are 2000$ original mercedes are around 4250-4300$

for that kind of money you can buy original disc brakes

 

look at this

http://www.youtube.com/watch?v=UL7A6Fb8AGw