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Drums or disks for towing?

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11K views 15 replies 9 participants last post by  BooFoo  
#1 ·
With all the newer trucks coming with disk brakes and having higher GVW and towing capacities, are they better for towing heavy loads than drums? I just pulled my replacement shoes out of the box and wow. I don't remember them being that big. They're 3.5 or 4" wide. I just look at the brake pads for discs, and it seems like there is no comparison. Plus all the class 8's run drums still. So, are disks really better, both in stopping power and brake fade (I think that's what it's called when heat builds up on the rotor/drum)?
 
#2 ·
Discs dissipate heat much better then drums, all around a lighter package, no adjustments, easier service/replacement. Flipside to drums are they are a big heavy protected package (mud, dirt, etc etc). On-highway trucks now come built with disc brakes also.
 
#3 ·
Must have missed that. I'm just looking at the pads for the front of my truck, vs. the drums on the back. HUGE difference. I was wanting to upgrade to an 03+ dually axle, since they come equipped with discs as well as 3.73's. The surface area is where I'm getting hung up on, I suppose. 3x the area on drums vs. the pads on disks. But then again, they must be outdated if the big rigs are changing over to disks as well.
 
#4 ·
Also remember 70% of braking is in the front bc of inertia and weight (motor, trans, blah blah), so the wear is understandable.
 
#5 ·
Jason, the discs are a HUGE advantage! My truck stops MUCH better and more controlled it seems with the discs out back, especially towing. Granted, I also changed the front axle as well so I have the larger brakes up front as well. But, over all, its a huge difference IMHO.
 
G
#6 ·
On 2009-05-22 21:44, Bandit wrote:
Also remember 70% of braking is in the front bc of inertia and weight (motor, trans, blah blah), so the wear is understandable.

that is not completely true its more like 55%, when the rear brakes are adjusted properly and you have a correctly functioning system they hit first before the fronts do, when the rear brakes are out of adjustment or if you have bad shocks it causes the front to work too hard and they glaze and warp rotors and crack the pads.


that is why back in the late 80's early 90's there was only rear wheel abs as the rear brakes hit first and would be the first to lock up.
 
#7 ·
I was surprised, Ken, to find that my '98 has rear ABS only. NAPA doesn't even list a front hub bearing in the non-ABS style. Only the ABS. Must have been the last year for that, as the '99s I've seen have 4 wheel ABS. Lucky for me, as the bearings are $400+ each.
 
#8 ·
disks have more clamping force than drums do and the reason the rears lock up easier and faster is because of there being a lot less weight not necessarily more stopping force than the fronts hence the reason when u power brake u hit the brakes so the fronts lock up and the rears can still spin... and drums do protect against road debris but if u get in mud and water they will trap that in there and rot away springs and other stuff inside that if they brake ur in for some trouble... disk breaks in my opinion are much better they dont get as hot they stop better there is more stopping power and alot less maintenance the only down side is that u usually go through pads faster than u do shoes... and remember another thing about drum brakes if they are adjusted properly there is more drag on the wheels at all times and with disk brakes and the majority of the stopping is done by only one shoe the other shoes main purpose is to apply pressure to the shoe doing the stopping... that is just my understanding and my opinion on the subject
 
G
#9 ·
On 2009-05-23 11:37, shawnsack wrote:
when u power brake u hit the brakes so the fronts lock up and the rears can still spin

on a rear drive vehicle you are overcoming the brake pressure on the rear axle with the engine, that is why they spin, it would be the same effect to spin front tires on a front wheel drive car while holding the brakes

and remember another thing about drum brakes if they are adjusted properly there is more drag on the wheels at all times

not true it only has drag for a couple miles when first adjusted then they seat in

and with disk brakes and the majority of the stopping is done by only one shoe the other shoes main purpose is to apply pressure to the shoe doing the stopping

also not true,(i believe you meant pad not shoe) the outer pad is pulled in by the inner pad via the pressure of the inner pad touching the rotor and then causes the caliper to slide on its slides to pull in the outer pad, if all is functioning as it should there will be almost no distinguishable difference to the wear of the inner pad to the outer pad as they should wear the same , if not then you have a caliper sticking in the slides or pads sticking in their saddles
 
#10 ·
well ive never been able to power brake a car by hitting the brakes cuz the backs dont have enough weigh and braking force on them to hold the car but yet now be too much pressure to hold the front wheels from spinning unless u use the e-brake... and i mean shoes... with pads the both do equal amount of the stopping power... but alot of drum brakes the shoes are different sizes... the one on the front often has less surface area than the rear shoe cuz when u hit the brakes the cylinder does push both shoes out but the front shoe then tries to roll with the drum and pulls away from the wheel cylinder and in affect pushes the adjuster against the rear shoe and since the one side of the wheel cylinder went out that side can go in then the back shoe rests against the pin keeping it from turning with the drum so in reality the wheel cylinder is pushing out the front only to grab the drum and then the force from the drum turning forces the rear shoe into the drum and does most of the stopping power... now im not saying the front shoe doesnt do any of the stopping power but the majority is done by the rear shoe unless ur going in reverse of couse... but if your calipers and sliders are all working properly in a disk brake setup your pads are both doing equal work and the piston on a caliper is much bigger than the one on a wheel cylinder therefore you have more clamping force
 
#11 ·
On 2009-05-24 07:06, shawnsack wrote:
well ive never been able to power brake a car by hitting the brakes cuz the backs dont have enough weigh and braking force on them to hold the car but yet now be too much pressure to hold the front wheels from spinning unless u use the e-brake... and i mean shoes... with pads the both do equal amount of the stopping power... but alot of drum brakes the shoes are different sizes... the one on the front often has less surface area than the rear shoe cuz when u hit the brakes the cylinder does push both shoes out but the front shoe then tries to roll with the drum and pulls away from the wheel cylinder and in affect pushes the adjuster against the rear shoe and since the one side of the wheel cylinder went out that side can go in then the back shoe rests against the pin keeping it from turning with the drum so in reality the wheel cylinder is pushing out the front only to grab the drum and then the force from the drum turning forces the rear shoe into the drum and does most of the stopping power... now im not saying the front shoe doesnt do any of the stopping power but the majority is done by the rear shoe unless ur going in reverse of couse... but if your calipers and sliders are all working properly in a disk brake setup your pads are both doing equal work and the piston on a caliper is much bigger than the one on a wheel cylinder therefore you have more clamping force

Holy {expletive} that's hard to read! :twak:
 
#12 ·
On 2009-05-24 08:46, Maddog Forever wrote:


Holy {expletive} that's hard to read! :twak:

:withstupid:

shawnsack,
Do you really think you've discovered a major flaw in Louis Renault's design that has gone unnoticed for 107 years?

:roll:


outal/Ken knows what he is talking about and you...well I won't say you don't know what you're talking about because I can't quite sure figure out what you're trying to say.


Jason,
Look how many guys running hotshot rigs up and down the highway with 15k lbs+ on their trailers have been running drum brakes (on the rear) for years without problems.

Is it possible to get a disk brake setup on your truck that will do a better job than the drums currently on it? I'm sure there is, but at what cost? At that, do you tow enough heavy stuff with regularity that you NEED such?
 
#13 ·
I just did a disc brake conversion this weekend and the difference is ten fold, before my rear drums would squeak, lockup at slow speeds and pull hard to the right. With discs the brake feel perfect and even. Plus side to it is maintenance, replacing pads and rotors are now a breeze compared to getting off a rusty drum and doing adjustments once in a while.
 
#14 ·
There is another reason that disks are better than drums. When the gases are released on from the brake pads during braking on disk brakes the gases can escape easily. Drums on the other hand give no place for those gases to go. The gases get between the drum and the pad and no braking occurs. That is why most vehicles for years have disks on the front so that under heavy braking the brakes dont fail.
 
#15 ·
OK. So after reading all this, how much would a disc brake conversion cost for a 97 ram 1500 5.2L sport with a 9.25 axle with 3.55 gears?

I've checked around in the past and they were like $1000 and just wasn't worth it, are they cheaper now?

Is it better to just pull a d60 from a 2500 and install it with the same gears as the front.
 
#16 ·
What was this thread about?

anyways. My .02 for a city stop and go vehicle that is going to see shody maintance (ie the typical car or truck nowadays) disk are the clear winner. Any semi-retarded monkey with a ratchet can change pads, and most parts houses will turn rotors. So the "typical" vehicle has a better safer working brake system. Now having said that having worked in a brake shop the number of people that would come in with rotors worn all the way through is freaking scary and makes you want to not even be on the road.
Also if done properly and adjusted drums seem to last longer. Of course it requires that you have more than the semi-retarded monkey. Also the whole gassing issue, which on a big rig going over the road how often do they have that issue? Also growing up around semi's I know they are usually maintained alot better than the average "car".



Oh and did I just not understand. Or did the one guy say he couldn't do a brake torque? Cause I know I have in disk brake setups, drum setups, etc. Me thinks not enough balls under the hood.