Disc brakes or drum brakes?

We have disc brakes on our trucks and newer trailers. There's no doubt I'd go with discs. Fully loaded I can stop much much sooner than with drum

 

Maybe actually see how truck discs work before stating that. They are not like auto discs. There is no "return spring". The return is air over mechanical. As is the application. And there is an air gap between the pad and rotor that is adjustable. And adjusted properly the pads don't touch the rotor.

 

This is true. Our mechanics can adjust the gap between the rotor and pad with a turn of a wrench. Makes adjusting the brakes very easy

 

Aside from being air actuated, they are a pretty typical floating caliper design, like 90% of automotive disc brake systems:

Yes, you can set the total clearance between the pads and the rotor. You cannot, at least on the Bendix system, ensure that gap is evenly distributed between both sides of the rotor. It is a floating caliper, like 90% of automotive disc brakes, so it relies on the rotor pushing the caliper back to the center position when the brakes are released. Outside of the laboratory, those guide pins/bushings tend to face extreme elements, get corroded, and not slide perfectly smooth. The more neglected the guide pins, the more force it takes to slide the caliper. Any force less than that force necessary to move the caliper results in brake drag.

In addition, you'll find that rotors don't always stay true. So you'll often have intermittent drag corresponding with a warped rotor making contact during portions of the revolution. Jack up a disc brake equipped car and spin the tires -- you'll probably hear this on at least 1 of the 4 corners.

 

I would still vote for disc brakes. I love them and our company won't go back to drum. The pads last much longer and the safety of them compared to drum is far superior

 

Thanks, DD. Coming from a fuel hauler, whom I have the utmost respect for, your opinion trumps all. It's sad people hold on to old ways of life (which goes far beyond just trucking) and won't try something new, even if it's proven to be better, "because that's how grandpa did it".

 

Don't have bendix. Use meritor. The spring is not in the caliper. And I can jack up any wheel and spin without the pad dragging.

 

[QUOTE="semi" retired;4408987]Thanks, DD. Coming from a fuel hauler, whom I have the utmost respect for, your opinion trumps all. It's sad people hold on to old ways of life (which goes far beyond just trucking) and won't try something new, even if it's proven to be better, "because that's how grandpa did it".[emoji106][/QUOTE]
I wasn't sure about them at first, thought they would prove to be more talk than walk.


Until I drove our trucks. all our trucks have discs and our newer trailers have them as well. When loaded I've come to a stop in no time at all. You don't have to push as hard on the brake pedal.

My truck has a trailer with drum brakes, you can feel the truck slowing down faster than the trailer when the trailer knocks forward into the fifth wheel lol. Plus you have to get on the brakes pretty firm for it to begin slowing down. I'm hoping to get a newer trailer soon.

All our newer trailers have lift axles on the front axle so when you're empty it's less wear on the tires and brakes. Honestly if I were to buy a newer truck I wouldn't think twice about disc brakes, it'd be a no brainer for me.

 

I know that I no longer have to do the brakes on the tractors before the trade, which I had to do every one with drums. You can see the picture of the ones on a trailer at approx. 500K. It may go 750K before replacement. Never had a trailer close to that with drums. Have no S-cams or slack adjusters to grease or adjust. They run the west mountains every week and I still have never seen a warped rotor. When the west trucks can stay around 7mpg @75mph then I don't care if the brakes drag or not.

 

Discs all the way. As was stated they aren't good for vocational.

I haul 5 axle super b trailers and Going down a icey hill with drums the pup likes to dog tail out a bit...... the super b sets with discs keep perfectly straight.

And discs are way easier to do a brake job on. Someone ealien said drums are easier and that is not accurate.