Alot of 18 wheelers DO have disc brakes.

 

Yup. This article is from 10 years ago when the current generation of air disc technology was new and still being developed:

Air Disc Brakes In Your Future?

Air discs became standard on Peterbilts back in 2010.

And here's a Bendix white paper on the 'new' generation of air disc:
http://www.foundationbrakes.com/medi...discbrakes.pdf

NHTSA has mandated that ALL new semis stop shorter. They didn't mandate disc brakes, but that's pretty much the only option for them at this point. So, yes, US semis have disc brakes and they're going to be getting more common. And in Europe, pretty much any recent semi and trailer you see over there will have discs not drums.

 

I work on and drive 18 wheelers all the time, Have NEVER seen disc brakes.
Show me ONE that is actually driven

 

While disk brakes are MUCH easier to assemble, that is not the only reason that vehicle manufacturers have gone from drums to disks. Disks can vent away heat that is produced while braking, unlike drums. They can also self clean, which is why water doesnt negatively effect disks like it does drums. That being said i have never wished that I had disks on the rear axle of any truck I have driven. Ill keep my drums becuase they do everything i need them to do and they are free

 

We have 3 trailers at the farm I work at that have disc brakes and the neighboring farm has a 48 foot and a 53 foot trailer that has them.

 

TRUCK, not trailer. And do they stop any better than drums? Yeah, didnt think so.

 

You said 18 WHEELER wich in most cases is made up of a truck AND TRAILER in most cases. Considering that those big trailers gross at 105500 pounds and stop just as good if not better than our other trailers I'd say they work better.
Just to make my point- I used to have a 1970 Torino that came with power drum brakes. After almost running over a buddy on his motorcycle while we were racing(dumb kids), I put on a set of factory Ford disc brakes for that car with quality NAPA pads. It reduced my 60-0 stopping distance by 18 ft. No other changes made to the vehicle, and the drum brakes were in good operating condition. I was an ASE certified brake technician at the time and stayed on top of my brakes.

 

Did you even read the white paper from ****BENDIX**** that I linked above? Yes, they stop better. And if you want to see one that comes with them standard, here you go:



It's the Peterbilt 587. And every single one of them made after 2010 comes with disc brakes standard unless the operator specifies (and pays extra for) drums. The Kenworth W900 and T660 have also been offered with air discs since about 2004.

 

BULL S H I T. I drive for a guy who has nothing but peterbilts. 20 of them to be exact and they ranger from 07s-to 2012s and NONE of them them have disk brakes.

And if I can lock up a drum break grossing 110,000lbs, there is no need for disc brakes, they will do no better

 

Of course. 4 wheel drum brake SUCK. They get dart and inconsistent. But that is what happens when you have them on the front.. But last I heard we were talking about rear drum brakes and how disks are no better on a truck

 

Peterbilt says otherwise. You also obviously didn't read the Bendix white paper.

Source link below. I commend the lines about "front brake" and "rear brake" to your attention.

..:: Peterbilt Motors Company ::..


How would you like your bull by-product returned to you?

Also, great, you've locked up your wheel. Now you can't steer. Disc brakes provide better 'feel' and modulation so you don't HAVE to lock up your wheels to get hard braking.

 

Not bull. I do services on these trucks too. ALL drum brakes.

And never had a front lock up on steer, just trailers in over 2 million miles.

And your link dont work

 

Yup, but that doesn't change the fact that they are offered and come standard on them. You know they can be ordered a billion different ways - lots of companies don't want to go to air disc yet and some dealers don't trust the new air discs, so they're ordered with the drums (just like on pickups when discs started off as optional). But it still doesn't change the fact that the 587 ships with air discs and it shoots down your point about them not coming with them. Or do I need to drag out the Kenworth brag sheets too?

I've seen UPS drivers lock their steer tires up on hard stops. Yes, the guys in tractors not the brown box trucks.

Edit: http://www.peterbilt.com/aero587.4.aspx - link works just fine here. If not, Google Peterbilt 587, go to the peterbilt.com link listed there, then click on the "Full Specs" tab.

 

Well if they are so good and have to stop a truck in 250' then why are drums even offered? BECAUSE THEY WORK

EDIT: I see the discs are an option as of 2011. But that doesnt mean they stop better

 

[quote=Diesel_Brad;12306478 But last I heard we were talking about rear drum brakes and how disks are no better on a truck[/quote]
I thought we were talking it our Ford pickups not 18 wheelers if you want to go there. Ford went to 4 wheel discs on their newer trucks so they could haul and tow more than our older trucks an d still stop better than our older trucks. Furthermore if you are locking up your drum brakes you are skidding NOT stopping, disc brakes are able to slow down faster than a drum brake without locking up and they are more resistant to fade from heat because they cool better and are self cleaning.