???disc vs drum brakes

[01cummins4ever]

9 hours ago, Russ Roth said:

 

 

 

Technology has passed you by then.  I texted my brother yesterday AM and he called right back since he was waiting to get unloaded.  His 2015 Mack has discs on the front steer and drive axles and drum on the tag axle which I think the company put on.  They do come from the factory too but it is cheaper for them to put them on in their own shops.  I forgot to ask him about the new trailer he is pulling to see what it is running for brakes.  He did say the set up does not look the same as an S cam but the fire truck I drove did look and adjust like S cams.  Not sure now how they work in either case since I retired in late '99 and the truck was new about '94 or '95. 

 

Ha! guess that's what happens when you live in the back woods, I have been with the same company for 20 years and have never came across a truck with discs, I have even sat in on new truck spec. ordering, and discs don't even come up as an option. We run mostly freightliners, international and mack, where I work I mostly do all the oversize loads with my rig. I have had my Freightliner since 2001, and personally hope to keep it until I retire from here. I dont like all the electronics and emissions there putting on these trucks these days ( just like our pick up trucks)  For braking I believe mass friction is the best,, bigger drums and bigger shoes mean more friction area, but will also increase heat and take longer to cool, but with proper engine rpm and gearing, and use of jake brake, the brakes should see minimum use.

[Mopar1973Man]

7 minutes ago, 01cummins4ever said:

but with proper engine rpm and gearing, and use of jake brake, the brakes should see minimum use.

 

Bingo... This man has it nailed down. Like myself I'm a exhaust brake owner I clear over 180k miles on a set of brake pads. There is no reason why you would have to upgrade or modify existing service brakes if use in combination with exhaust brake. Now of course a diesel vehicle without a jake or exhaust brake is just asking for high wear patterns of brake pads being the diesel engines have very low resistance during deceleration.

 

With me living in the mountain of Idaho and hauling trailer loads of firewood and my RV still to this day I rare touch the service brakes unless I'm stopping. All the slowing down is done with a combination of gearing down and letting the exhaust brake hold me back. So my service brake remain cool and don't normally get used till speeds under 25 MPH.

 

so at this point looking at at least local laws compression or jake brake use is illegal to be used in city limits. So that being said what is the average city speed limit 25-35 MPH. Even for OTR truck this is rather light duty for stopping and can be easily stopped using either disc or drums.

 

I read an article a while back stating that drum brake are more efficient for stopping power but more prone to heat issues and water issues. Where disc brake tolerate heat better than drum and shed water better.

Edited June 10, 2016 by Mopar1973Man

[TFaoro]

2 minutes ago, Mopar1973Man said:

 

Bingo... This man has it nailed down. Like myself I'm a exhaust brake owner I clear over 180k miles on a set of brake pads. There is no reason why you would have to upgrade or modify existing service brakes if use in combination with exhaust brake. Now of course a diesel vehicle without a jake or exhaust brake is just asking for high wear patterns of brake pads being the diesel engines have very low resistance during deceleration.

 

With me living in the mountain of Idaho and hauling trailer loads of firewood and my RV still to this day I rare touch the service brakes unless I'm stopping. All the slowing down is done with a combination of gearing down and letting the exhaust brake hold me back. So my service brake remain cool and don't normally get used till speeds under 25 MPH.

I'm still waiting for someone to make an exhaust brake that goes between the two turbos on a compound setup.

[Mopar1973Man]

Just now, TFaoro said:

I'm still waiting for someone to make an exhaust brake that goes between the two turbos on a compound setup.

 

Reason why I won't upgrade... I still enjoy the huge stopping power of my exhaust brake.

[TFaoro]

Yeah... my dad's 96' 12V has a pacbrake on it and it's awesome. It now has 160K, most of which have been pulling a 20ft gooseneck cattle trailer or a 25ft tandem dual gooseneck flatbed. It's had 1 set of new front brakes and the rear drums are still original. If you ever driven a pre-97 12v you know how bad the brakes suck too!

[AH64ID]

Given the space limitations of a 17" wheel I am not sure you could get better braking power out of a drum than a disk. With big 22.5 or 24.5" wheels there is a lot more room for big drums. 

 

Brake fade is much better with discs. So while a drum may have better stopping power at the top of the hill the disc should have better stopping power at the bottom. 

 

I'm a huge fan of exhaust brakes but they are fairly irrelevant in the conversation of rear brakes. 

Edited June 10, 2016 by AH64ID

[01cummins4ever]

I pulled the rear drums off my dodge two years ago at about 240k or so, thinking they were way over due for replacement. but after beating on the drum for and hour and soaking in penetrating oil to get it to come off. It wasn't really worth the hassle, They were only about half wore. So just proved that these rear drums don't do much on these trucks. They will probably rust away before wearing, I get better braking power with the 9000lb. fifth wheel behind it than I do with the truck by itsself

[KATOOM]

1 hour ago, TFaoro said:

I'm still waiting for someone to make an exhaust brake that goes between the two turbos on a compound setup.

 

Just curious as to why you'd want that?  As long as the exhaust brake was connected to the later housing (whether or not thats even possible), the same would be achieved.

That there had me wondering if anyone has ever configured a VGT in compound setup.....and I guess they have.

But in reality if someone with compounds really wanted an EB then an inline model could still be used.

 

38 minutes ago, 01cummins4ever said:

I pulled the rear drums off my dodge two years ago at about 240k or so, thinking they were way over due for replacement. but after beating on the drum for and hour and soaking in penetrating oil to get it to come off. It wasn't really worth the hassle, They were only about half wore. So just proved that these rear drums don't do much on these trucks. They will probably rust away before wearing, I get better braking power with the 9000lb. fifth wheel behind it than I do with the truck by itsself

 

FYI..... If you jack up the rear axle and place it on stands.  Remove the tires/rims and any stud fasteners.  Replace a couple lug nuts only partially threaded on the stud.  Start the engine, run it in gear and then slam on the brakes.  The drums should (in theory, but it does work) pop off.  The couple lug nuts are to keep it from flying off into your garage.....

Edited June 10, 2016 by KATOOM

[AH64ID]

With the exhaust brake after the 2nd turbo the response time is increased. There is also enough air in the exhaust that it "pops" when released. 

 

It would be nice to have it between the primary and secondary. 

[KATOOM]

Interesting.....

How about a VGT supplying a non VGT.

[AH64ID]

2 hours ago, KATOOM said:

Interesting.....

How about a VGT supplying a non VGT.

 

That would work. 

 

I haven't really kept up on stand alone controllers but I sold my HE351VE because I wasn't impressed with the controller options and interfaces a few years back. 

 

It would be cool to take an elbow mounted brake and adapt it to the twins, if room permits. 

 

The exhaust brake isn't what's holding me back from getting twins. If I bit the bullet I would just go remote mount as close to the primary as possible. 

 

For twins I just have a hard time justifying them. I can run up a 4-5% grade at 70 mph on a 75° day above 6,000 feet at 20K GCW, so I am not sure what I would gain from towing as I don't plan on getting much heavier or going faster. 

 

Until UDC came out I was seriously considering them but proper tuning took away the "need" for my application. 

[TFaoro]

3 hours ago, KATOOM said:

Interesting.....

How about a VGT supplying a non VGT.

I'm waiting for @Me78569 to get bored with his turbo so I can buy it and build the setup  

[CSM]

4 hours ago, TFaoro said:

I'm waiting for @Me78569 to get bored with his turbo so I can buy it and build the setup  

 

then I'll buy your twin setup.  

[Me78569]

lol you guys are nuts.  I can tinker until the end of time with my current setup, I may never sell the piece of junk.  Just imagine if I get the smarty pro 

[Russ Roth]

15 hours ago, 01cummins4ever said:

Ha! guess that's what happens when you live in the back woods, I have been with the same company for 20 years and have never came across a truck with discs, I have even sat in on new truck spec. ordering, and discs don't even come up as an option. We run mostly freightliners, international and mack, where I work I mostly do all the oversize loads with my rig. I have had my Freightliner since 2001, and personally hope to keep it until I retire from here. I dont like all the electronics and emissions there putting on these trucks these days ( just like our pick up trucks)  For braking I believe mass friction is the best,, bigger drums and bigger shoes mean more friction area, but will also increase heat and take longer to cool, but with proper engine rpm and gearing, and use of jake brake, the brakes should see minimum use.

 

Interesting you have an '01 Freightshaker.  My brother drove his '01 Mack since new and put 1.4 million miles on it and had hoped to retire out of it too.  A few months ago it blew something out of the block that had to do with the injection system and they took it away from him and made him (literally) drive a new(er) one.  I think it had about 8,000 miles on it.  He does not do change well to start with and has said the same thing about the new ones.  Too much downtime and too much pain in the butt with all the emission stuff. This one is a 12 speed auto-shift and he won't even call it a truck.  It has fleet programing for the tranny and he says almost no control over it and you never know what it's going to do for sure.

The company repaired the '01 and were going to peddle it down the road but called the truck museum in Brooks, OR to see if they would be interested in it.  They were and it has been totally redone and restored to look better than new.  It also says "44 years and counting-Bruce" on the doors. They sent him with it down to the ATHS truck show in Salem, OR a couple weeks ago.  I asked him if he let them know he would like it back.  His answer-----they already know that!  LOL

[Cowboy]

Drum + Exhaust Brake > Disk.  I wouldn't let the rear disks be the "Be all end all" of your decision.

 

Tyler, you could always get a 4" inline unit, that's what the '99 has.

 

I must have gotten luck with the '96, The brakes on it have proven fine for me.  I'd have to do some back to back testing to notice much difference between them and the '99 when hauling.  Then again it does have a '97 vacuum booster so...

 

EDIT: Whoops, we're on page two...

The '99 has the EB across from the drive shaft, and while there's a little delay, it's not that bad in the scheme of things.  And yes it does sneeze when you let it of.  Sounds like a big rig. 

 

 

Edited June 11, 2016 by Cowboy