Talking about Wheels

[Jon Wehrenberg]

Jim,

Assuming you have the screws holding the drum in place removed, the next step is to back off the slack adjuster. If you haven't caged the emergency brake do that and then back off the slack adjuster by lifting the sheet metal disc and then turning the square adjuster counter clockwise.

If the drum is stuck to the hub as Ken describes give it a whack.

When re-assembling use never-seize on the brake drum screws because that will save a lot of effort the next time. They are usually a pain to loosen. I urge you to look further into using lube on the wheel studs. As far as I know that is not recommended.

[stevet903]

From the Prevost maintenance manual:

7. WHEEL STUDS
Stripped threads may be the result of excessive torquing, or may have been damaged during wheel installation, when placing the wheel over
the studs. A stud having damaged threads must be replaced. Broken studs are a direct result of operating with loose stud nuts or improperly
seated wheels. When a broken stud is replaced, the adjacent studs, on each side of the broken one must also be replaced, since they could have
been subjected to excessive strain and may be fatigued.
When installing wheel studs to hubs, check nuts retaining the wheel stud to wheel hub and if they are deformed, damaged or severely corroded,
install new parts. Install nut (and washer where applicable) to new stud and torque to 110 - 130 lb-ft (150 - 177 Nm) for studs mounted on front and tag axle wheel hubs and torque to 450 - 500 lb-ft (610 - 680 Nm) for those mounted on drive axle wheel hubs.

[stevet903]

From the Jan 2009 Alcoa wheel service manual: (It has some nice diagrams as well!!)

Hub pilot wheels:

Two-piece flange nuts with a 33mm hex head design (see Section5-2), used with hub piloted wheels
should be tightened to a torque of 450 to 500 foot-pounds. Two-piece flange nuts with 1-1/2-inch
hex head design and other designs have different torque requirements. Inquire of the manufacturer for
the proper torque values. See section 6-2.
Wheel studs on both the right and left side hubs of vehicles utilizing the hub piloted wheel system
have right-hand threads.
Prior to mounting hub piloted wheels, generously coat the wheel pilot or hub pads with a non-waterbased
lubricant to minimize corrosion product build-up between the wheel and hub pilot. Excessive
corrosion build-up between the wheel and hub pilots can make wheel removal difficult. Do not lubricate
the face of the wheel, hub or brake drum (see illustration on the next page).
Lubricate the hub pads or the wheel hub bore generously with a non-water-based
lubricant.
Before installing two-piece flange nuts, lightly lubricate the stud threads and the contact surfaces
between the cap nut and the washer as illustrated below with an SAE 30W oil. This will minimize corrosion
between the mating surfaces. Lubrication is not necessary with new hardware.
Position one of the hub’s pilot pads at the twelve o’clock position. After positioning wheels on the
pilot pads, hand tighten all two-piece flange nuts, then tighten to the recommended torque following
the proper sequence shown below for your type wheel. After 5-50 miles of operation torque should be
rechecked, unless your documented fleet practices determine otherwise. Check torque frequently from
then on. If nuts require frequent tightening, studs break frequently, or wheel bolt holes are pounding
out, hardware and mounting practices should be reviewed.

Stud pilot wheels:

WARNING Lubricants should not be applied to the cap nut seat or to the cap nut-to-wheel
contact surface.
Oiled seats can lead to over-torquing which can stretch studs causing failure of studs.
Failed studs can cause the wheel to disengage from the vehicle, causing serious injury
or death.
Lubricants must be completely removed from the cap nut seats and contact surfaces if
applied accidentally.



It is recommended to torque to between 450 and 500 foot-pounds. If lubricated with SAE 30W oil
torque should be between 350 and 400 foot-pounds. Note: when dualing steel wheels with Alcoa
aluminum wheels, follow the steel wheel manufacturer’s recommendations regarding the proper torque
and use of thread lubricants to mount the wheel.

[JIM CHALOUPKA]

Jim,

Assuming you have the screws holding the drum in place removed, the next step is to back off the slack adjuster. If you haven't caged the emergency brake do that and then back off the slack adjuster by lifting the sheet metal disc and then turning the square adjuster counter clockwise.

If the drum is stuck to the hub as Ken describes give it a whack.

When re-assembling use never-seize on the brake drum screws because that will save a lot of effort the next time. They are usually a pain to loosen. I urge you to look further into using lube on the wheel studs. As far as I know that is not recommended.

New studs and nuts are on order as well as seals and other components necessary if the hub must be removed for stud replacement.
The drum retaining screws are removed and the drum is released, but not removed.
I will follow specifications and re-assemble studs and nuts DRY but I don't like it.

I have two maintenance manuals and can find no information in either about caging the brakes or re-adjusting the slak adjusters on completion.

Could you be more specific on the process. I have a hex nut/cap on the side of the slak adjuster and a square screw head on the end. If caging is not performed properly and I loose air pressure with the drum off, what are the consequences?? Will the brake assembly expand disastrously??

Does the T bolt in the brake chamber take part in the caging process?

I must go to Cleveland for the day and will be away from the computer.


Thanks, JIM

[Orren Zook]

Jim,

I'm going to send you a PM with the specs on the correct procedure for adjusting those slack adjusters/brakes.

[Jon Wehrenberg]

JIm,

Caging an emergency brake (so you can back off the slack adjuster) is not something to be taken lightly. First, use the "T" bolt supplied with the brake chamber. Make certain it is engaged by inserting it into the hole and turning it 90 degrees. The process is greatly simplified if the emergency brakes are released so you are not trying to turn the nut on the T bolt for the entire length of the threads under load.

After inserting the T bolt, reapply the emergency brakes. That takes all air pressure off the brakes and verifies the T bolt is in the proper position and secure.

It also allows you to work in that area without relying on air pressure (used to release the emergency brake) to keep the brake released. With the T bolt the brakes are held in the released position mechanically.

The square headed screw on the slack adjuster is to back the slack adjuster off so the drum can be removed. I will stay out of that discussion since Orren is going to help you there. It is a smiple procedure.

[Jon Wehrenberg]

Forgot to mention, after reassembly the adjustment of the slack adjusters can be done manually, but since they are self adjusting you can also fan the brakes and let them adjust themselves.

I usually disconnect the service brake hose and give the chamber shots of air from my air gun so the brake is being applied and released as would happen if you fanned the brakes. I'm sure Orren will cover this.

[JIM CHALOUPKA]

Thanks for the posts. I am beginning the process.

JIM

[Reagan Sirmons]

Jim, I may be too late on this comment but it relates to the removal and re-installation of the tires back on the rims. I am paranoid about my rims and recently had tires installed on the trusty Newell. The installers were somewhat careful but still damaged the rims by not covering the tire arms with cloth while installing the tires. We all spend a lot of time on these so I receommend close supervision or you may experience dents and bruises most of them being permanent. Thanks for all the info.
Reagan
Pres

[Kenneth Brewer]

Jim, I may be too late on this comment but it relates to the removal and re-installation of the tires back on the rims. I am paranoid about my rims and recently had tires installed on the trusty Newell. The installers were somewhat careful but still damaged the rims by not covering the tire arms with cloth while installing the tires. We all spend a lot of time on these so I receommend close supervision or you may experience dents and bruises most of them being permanent. Thanks for all the info.
Reagan
Pres

Amen. What he said.