This may be dumb....but will ask????

[dieselguy]

If you have a 12K - 14K trailer like many of us and can lock all 4 of your electric drum brakes on asphalt or concrete at say 30 - 40 mph ... DON"T EVER GET RID OF THAT TRAILER AND DRUM BRAKE SYSTEM as you have a one in a million unit. Most of the rest of us can barely lock em up on gravel unless we're traveling say 10 mph. Once you go disk brakes, it's like driving a car without a windshield then putting one on ... utterly amazing!
PS ... Locking up brakes as you probably know reduces braking efficiency in any given situation.

[laverdur]

I read the comment mentioning locking all 4 trailer wheels with drum brake. No recent advice regarding how to adjust trailer brakes has advocated locking up the trailer wheels. That is old school thinking. Sure, test it at 30-40 mph on clean dry pavement but the test is not whether the trailer wheels lock up but, rather, that the TV does not feel like it is being pushed by the trailer.

[Jester]

Originally Posted by laverdur

I read the comment mentioning locking all 4 trailer wheels with drum brake. No recent advice regarding how to adjust trailer brakes has advocated locking up the trailer wheels. That is old school thinking. Sure, test it at 30-40 mph on clean dry pavement but the test is not whether the trailer wheels lock up but, rather, that the TV does not feel like it is being pushed by the trailer.

That is old school thinking but this is an area I know more them most.
I’ve spent the better part of 30 years arguing with state troopers at road side truck and trailer inspection of heavy vehicles and buses.
The state police have taken the opinion that a trailer with electric brakes should lock all wheels if the brake away pin is pulled at 10 mph.
My argument has always been the trailer should stop quickly without lockup.
If any wheel should lock , control is compromised.
Feel free to comment with your opinion .

[Dave W]

You do NOT want to ever lock the trailer wheels on a hard stop. If you do lock them, you have just "killed" the coeffiant of friction between the tires and the road. In other words, that trailer isn't helping you stop.



Personal experience - I was following another 5er on a crowded 65mph interstate. The semi in front of him did a panic stop. That 5er behind him locked up his brakes and ended up sliding down the shoulder with smoke boiling out from underneath , almost rolling his rig yanking it to that shoulder. I was able to stop - no traffic accordian hit, about 8-10 feet short of that semi. I'm a complete believer of disc brakes.



Then there was that young lady in Montpelier, VT that decided to not stop before entering the road............



Others can add their experinces but in both cases, magnet operated brakes would not have stopped me in time

[mhs4771]

Why do you think that Auto Makers switched to Anti-Lock Brakes??

[paulinbaja]

I want to thank all you have suggested not locking breaks. That is great advice. My comments simply suggest the effectiveness of breaking systems not that locking breaks is a thing to do.

[Dave W]

Originally Posted by mhs4771

Why do you think that Auto Makers switched to Anti-Lock Brakes??

For only another $3000 or so bucks, you can add a Tuson ActuLink Electric-Hydraulic ABS system to your TT/5ers $2000 +/- disc brake system

[MARK A]

Originally Posted by CruzinMooses

Let me start with my background...35 years as a truck driver that has logged over 4 million miles. I also spent the last 6 years as a part time mechanic in the shop where I drive truck working on trucks and trailers so I have replaced a lot of brakes....


Why would you replace disk brakes with a drum brake? What happens when metal gets hot ? It expands, basic physics. So you have a brake drum that gets hot and expands the brake shoes have further to travel to make contact which leads to brake fade, that is why major hills have run away truck escape routes.



Now lets look at disk brakes, the rotor is in the middle of the brake pads which are compressed together to brake. now if the rotor gets hot and starts to expand then the gap between the rotor and pads get smaller not larger. That being said hot metal still will not brake as well as cold metal but you would still have better stopping ability with the disks over drum.


Also as one other poster asked have you ever had to crawl under a trailer to break loose (IE Bang the crap out out the brakes) I have more times that I care to think about and it sucks. I know the OP said he has an air dryer on his truck but trust me you still have enough moisture in the air system to freeze up air brake valves. I know, been there, done that...


Do yourself a favor and leave your electric over hydraulic disk bakes alone...


Meanwhile I get to order and then install replacement disk brake for my HC to replace those crappy/cheap electro mechanical drum brakes...

I don't think anyone was suggesting replacing disc brakes with drums?

I think the question was air or hydraulic..


Mark

[Charlie 3931fb]

Originally Posted by MARK A

I don't think anyone was suggesting replacing disc brakes with drums?

I think the question was air or hydraulic..


Mark

Mark is right. Keep the disk brake and convert them to operate with air pressure from the truck. Just like you have on your 18 wheeler.

Charlie