how much better is a disc brake front end?

[theskytoucher]

I went from manual drums to power brakes all at once and the difference was incredible!! I would reccomend the swap but i would also say to learn how the drum brakes work as well before you remove them cause down the road you never know when your going to need some knowledge about how drums work!! When i did my swap i replaced steering linkages, kingpins, all the bushings, springs, and i put on cross drilled and slotted rotors and i think i have 500- 600 in it!!

I had the experience of a set of drum brakes going out of ajustment (spring broke) and that was enough to make me do the swap!! That and i had a bearing seize to the spindle about 2 week after the spring broke!!! Fun Fun!!!

[montana_hiboy]

I went from manual drums to power drums to power discs. By FAR, the biggest difference was with adding power to the drums. The truck stopped great and I didn't need to stand on the brake pedal at a stop light to keep it from creeping.

After I switched to power discs, its still stops very well but I don't feel it stops any better than with power drums. However, I understand it will be better in wet situations or down hills.

Like dc and and some others have elluded to previously, the vast improvement of the disc brake swap comes not from the the disc brakes themselves but from simply going from manual to power brakes, if you're going from manual drums to power discs you're gonna see a huge improvement in braking capability but the jump from power drums to power discs just isn't that huge of an improvement IMO.

[390Nut]

Some interesting reading.

http://www.almc.army.mil/ALOG/issues/Se ... rakes.html
http://www.morryde.com/pdfs/brakes.brochure.pdf
http://fleetowner.com/management/fleet_timeline_brakes/
http://bulktransporter.com/mag/transpor ... spicer_jv/
http://farmindustrynews.com/mag/farming ... g_power_2/
http://www.brakingtechnologies.com/PDF/IMechEPaper.pdf
^^this one is good reading; the problems considered with standard disk brake technology is compounded with drum brakes, regardless of what anyone tries to tell you.

There's tons more resources out there, but it boils down to this.

Anyone who tells you that drum brakes are "good enough" or there is no "difference" between drum and disk brakes is in denial.

There is no doubt that drum brakes DO work, and have worked well for a very long time. However, disk brakes DO work BETTER, and are MUCH SAFER than drum brakes. Especially when you're driving 2 1/2 tons of steel (or more) down the road. Speed is irrelevant. You don't have to be racing hard to have a difference. Disk brakes just plain work better, and stop you faster, whether you can "feel" the difference or not.

Even if it's only 10% faster, that's a rear bumper you're 10% LESS likely to hit when someone stops suddenly in front of you, a child you're 10% LESS likely to hit when they dart out in front of you (yes, it really does happen), etc, etc.

Should be a no-brainer; If you can, make the swap. If not, fix what you've already got correctly (like I did) and do it later. Just don't let anyone tell you there's "no real benefit" to swapping to disk brakes (power or otherwise).


( a little more than 2 this time )

[dcbullet]

I'll tell you this, when I have to change the pads in 10-20 years, I'll much prefer to change those than drum shoes.

[cdeal28078]

I love my disc brakes, if I ever own another bump I'll end up putting discs on it as well. Just too easy to do to NOT do it. Buy a doner truck and re sell what is left over. I paid for my power disc brake, power-steering, automatic tranny swap doing it this way and still made a couple of dollars.
clint

[F100builder]

I've got a complete disc front end from a dent that I will be installing very soon. I can't wait to get it done! It really isn't too hard to pull everything at the yard. Pulling just the spindles would actually be more difficult and time consuming than pulling the entire assembly as a unit and bringing it home for disassembly. Kingpins will not be easy to pull at the yard!!! You basically have the coil spring retainers, shocks, radius arm nuts, the beam pivot bolts, and the pitman arm to loosen and then pull it out from under the truck. Oh yeah, don't forget the brake hose brackets! Try to find two driver side brackets as they are BOLTED while the passenger side is RIVETED. I'm sure it's different from place to place but I only paid $100 for my entire setup including the pitman arm and steering linkage. Additional cost will be in either turning the rotors or buying new ones plus the pads. I got new kingpins with my drop beams so I'm ready to go. Just need to find the time! I'd say DO IT while you have the truck apart! It's a great upgrade! Take a look at Keith's tutorial on this very subject. It's good stuff! Good luck Ryan!

[rgoot01]

My post reply actually has nothing to do with the actual drum to disc conversion but to clarify the comparison to drum brakes on a p/up and the drum brakes on a big rig. The reason a big rig still utilize front drum brakes has nothing to do with heat dissipation rather it has to do with the fact that on a big rig there is a component in the braking system called a proportioning valve that drops that amount of applied brake pressure to the front drums. The reason for this is simply that when driving 80K down the interstate, a mountain pass, etc, the front brakes do not lock up which can be big trouble for 80k. Granted the proportioning valve is not on all rigs which is why we(diesel mechs) will generally adjust front brakes to where when the brakes are applied the shoes on the drives grab before the steer eliminating the front from locking up. Also drum brakes actually provide more stopping power than a disc could(have you ever seen the size of the shoes on a class8's?).

[1971ford]

i havent checked on this thread for a week!

thanks everyone for your replies..

ive just got to do it now

maybe someome can tell me what tools my dad will need when he goes in, so he can do it quick..er ? he'd like that.

thanks again for all your replies!

[390Nut]

Also drum brakes actually provide more stopping power than a disc could

[rgoot01]

The reference to drums providing more stopping power is towards big rigs not p/up's. The reason for my reply is due to fact that two comparisons were made regarding p/ip's to big rigs. I was simply explaining the reason why drums are still employed on big rigs. I did not however state that drums provided more stopping power on passenger vehicles. If you would have read all of what I posted and not just what you disagree with you would have also listed the rest of the statement that I typed in parenthesis. Furthermore as a Master Certified Diesel Tech. I would tend to think that I would know what I am talking about when it comes to big rigs. So roll your eyes all you want and believe what you will, but remember I am refering to the p/up to big rig reference, not the overall application of drum brakes on all vehicles!

[F100builder]

maybe someome can tell me what tools my dad will need when he goes in, so he can do it quick..er ?

He will need jack stands and some sort of jack unless the yard has it up off of its wheels by the frame already.
I can get the socket size later but he'll need some 1/2" drive sockets/wrench, end wrenches (for brake lines), 3/8" drive sockets/wrench, wire cutters (if you have to cut brake hoses), 1/2" drive BREAKER BAR for sure, and perhaps a small sledge.
He'll want to loosen and remove the rear radius arm nuts first. If he pulls the coils and shocks first, it'll be real hard to get a socket over them with the front dropped way down! It's probably a tad quicker to remove the top shock nuts next and cut/remove brake hoses. Next, pull the pitman arm from the steering box. Then, with a jack supporting the beam (one at a time), remove the clip from the top of the coil. Lastly, the pivot bolts are removed and the whole thing drops down and should be pulled forward to free the radius arms from their brackets.
It took a friend and me an hour or two to pull mine. I hope he'll have some help to lift and/or carry it! I hope I'm not forgetting something too! Good luck!

[rgoot01]

EXCERPT FROM FLEET MANAGER ARTICLE:
"Petresh believes the benefits of air-disc brakes include better performance, expanded service intervals and other maintenance advantages, plus much longer lining life."
This is nothing more than a belief such as ones belief in god. I am not saying drums are better. Furthermore the article clearly states the the improvement is not in the replacement of drums to discs rather the use of wider drums and and shoes till the discs can be more readily available at a more economical level. Yes some commercial vehicles do use disc brakes on the front end as oppossed to drums but these are typically found on commercial vehicles smaller than class 8. Yes there are class 8 mfgs. that are working with front discs but it is not industry standard as of yet nor is it standard equipment. Trust me if I have the option of drums or discs on my passenger vehicle I will always choose disc. I also never stated the fact that drums are better than discs. I also know that discs provide better stopping ppower than drums. All I am saying is that you should not be content to use drums or keep drums on the front end of your passenger vehicle because class8 trucks utilize this system, because even though the systems are relatively the same on class 8's and passenger vehicles, it is the application and components used in class 8's. One needs to first UNDERSTAND the air brake system on a class 8 and the many components that make up the system in order to do a comparison. Lastly I would like to state that I do know what is going on in my industry by way of advancement. Bu8t until the average person(you) understand the air system on a class 8 you are in no position to provide info to discredit anyone with a full understanding of the brake systems on a class 8, especially a Master Tech,CHEF!!

[390Nut]

I don't have to discredit you, just point out that you did it to yourself.

From post #39:

Also drum brakes actually provide more stopping power than a disc could.

And from your post above:

I also know that discs provide better stopping ppower than drums...

You'd make a great politician. Would you like some wine with that crow?

[rgoot01]

Whatever. Maybe we should spend more time reading the posts in their entirety and understand what its subject matter is and you would have ultimately understood that I am not promoting the use of drums on dudes truck. Merely I was trying to show how the use of drums on a class 8 is no reason to continue the use on a p/up. My defense was in that you cannot compare the usage between the two due to the apps. being different yet the same. To clarify and I am sure you will agree disc brakes on a p/up is definately better and worth the conversion, however the use on a class 8 as of yet no, due to many variables that still make the use of drums the better choice. But understand to that there are some trucks out there that have the slack adjusters on the front brakes adjusted so that when brake pressure is applied the steers actually do not grab. So in conclusion yes drums provide more stopping power on Class 8 due to surface area of shoe however on a passenger vehicle discs provide more stopping power. Until the performance of discs on Class8 is proven as fact and not someones belief drums will still be the brakes of choice due to the stopping power on these vehicles. Bare in mind that I am refferimng to the entire system,steer and drive axles as a whole, not just the steer which is the subject of the original post. Also my support for drums providing more stopping power was in reference to the class8 and my support for stopping power of discs is in reference to passenger vehicles. The large percentage of braking on a drum equpped class 8 comes form the rear axles as oppossed to a disc equiped passenger vehicle where the greater percentage comes from the front axle. This is why you should not compare the two as justificatio. So, no, I did not discredit myself. You just need to read the post in its entirety.

[ToughOldFord]