Broken brake drum

[Sam 4106]

Can a brake drum be broken by over tightening the lug nuts? I had new steer tires put on the bus Monday, and today when I was under the front greasing and planing to adjust the brakes, I noticed a broken drum. The guy that put the tires on my aluminum wheels also spun the impact socket against the wheel. Apparently he never heard of a plastic shield to prevent wheel damage. I noticed the damage when I was letting air out of the tires. They were inflated to 120 PSI. Rode like a lumber wagon on the way home. Everything considered, I wish I had installed the tires myself. Hindsight. I called the shop manager to tell him of the damaged wheels, and he responded that he would get 2 wheels coming. Hopefully he follows through on that. I don't want to drive the bus back to the tire shop until I get a new brake drum installed. I hope I can get a drum locally.

Thanks for any advise, Sam

[John316]

Would you quantify broken? I assume cracked...

[luvrbus]

Sam, you will not break a drum with over tightening the lug nuts a wheel yes

[Sam 4106]

John,

I called the drum broken because there is about an 1/8 crack from the inner edge all the way to the wheel. I won't remove the wheel  until the shop manager comes to my shop to look at the damaged wheels. I don't want any doubt that his guy caused the damage.

Clifford, thanks for the info that over tightening the lug nuts won't crack a drum.

Thanks for the quick responses, Sam

[Sam 4106]

I have a '76 MCI 8. In order to try to get a new front brake drum locally, I think it would be useful to know the brand of the axle. I've looked in both the parts and maintenance manuals but can't find that information. I found that the rear axle is Rockwell, can I assume the front is also Rockwell?

Thanks, Sam

[luvrbus]

Sam,on the drum dig around and you will find a Webb number any truck place can match it for you,Nicks Truck Parts 1-877-428-9683 are good at matching with measurements I buy Eagle drums there for around 100 bucks each and most of the time it's free shipping fwiw and DuraBrake is a good resource also

good luck

[TomC]

When buying a new drum, there are two different types of drums. One is a cast drum. They are one piece cast iron and should have some sort of balancing weight on them-these are the cheapest. Second is the cast iron with steel insert. Meritor makes these under the name of Steelite, and also there is Centrifuse. These have a cast iron outside with a steel insert where the brake pads rub against. Advantage to these-these are the best drums-they can get 3-5 lining changes (compared to replacing the cast iron drum at most every lining change [course this isn't that important to us]), they are lighter since steel is much stronger then cast iron, they are more resistant to heat cracking. Disadvantage-more expensive.

We carry the normal truck drum (16.5x7) for $85.00. A Centrifuse drum will be roughly twice that. I have 14.5 x 7 fronts-that will be more expensive then the truck drums. Good Luck, TomC

[RickB]

Sam

C&J in Minneapolis has a big inventory of brake drums. Call JD there and they'll hook you up.

Rick

[Sam 4106]

I removed the cracked drum and found the Webb number, 64004. It is 14.50" X 5". The new one will be here tomorrow. That number must be the best one that Tom described since it cost $222 plus $20 shipping. There is just over 5/8" of lining on the shoes so I will probably not live long enough to wear them out. I measured the cracked drum, as best I could, and it was still very close to 14.5" so the shoes should fit the new drum OK. All but one of the screws that hold the drum to the hub came out easily. The difficult one I had to give a few raps with a hammer and punch to get it out. so I don't think that drum had been on too long.

Thank you Clifford, Tom, and Rick for your timely advise, Sam

[Busn-Gramps]

Hi Sam, how did you make out with your wheels?

[Sam 4106]

Hi Busn-Gramps,

The tire shop is taking responsibility for the damage and replacing my wheels. I will try to get back to the shop after I get the new brake drum installed. I had considered just picking up the new wheels and changing the tires myself. But, the shop manager wants me to bring the bus to their shop so they can remount and balance the tires for me. I will be very satisfied if they can do the work without further damage. I have an idea that someone, other than the guy that damaged my wheels, will be doing the work this time.

Wish me luck, Sam

[gus]

I have to admire that shop manager, so many others make it as hard as possible to get proper work redone.

[Sam 4106]

I have the new brake drum partly on, but it is being difficult. The 2 drums have the same part number, they measure the same as the flange on the hub, and I have wire brushed and lubricated the flange. Still going on really hard by tightening all ten lug nuts against the drum, by hand with a 3/4" drive socket. Is something wrong, or should the drum fit the flange that tight? I can use my 1" impact if I have to, but I don't want to break the drum or hub flange. Any advise will be appreciated.

Thanks, Sam

[RickB]

Sam,

Don't tighten them any further until you either get an answer from someone with experience doing this same job here on the board or wait until morning and call JD or Curt, They'll tell you in two seconds whether thats normal or not. Good catching up with you on the phone the other day old friend and we look forward to seeing you and Char this spring/summer.

Take care and give us a call if you need anything,

Rick

[chessie4905]

Drum should go on with a snug fit, not real tight, this could be the cause of the other one cracking. Does the drum and hub have small holes for the flat head screws? If the drum is a nice fit with the studs, you could relieve the center hole hole a little if you can do it fairly evenly. Are your coach wheels hub or stud piloted? You could remove the other front wheel and measure that hub od and drum hole id to be sure your drum is correct before you do anything to it. Oh, and make sure the brakes aren't rubbing/dragging. Did you back them off completely before attempting to install new drum? Was the other drum cut with oversize shoes installed? can you still rotate the wheel while trying to seat the drum?