How do these brake drums come off?

[Fredward]

I'd like to take the drums off my MC-5 for inspection but can't quite figure out what tool is required. Is there an impact tool to fit my impact wrench to remove those big screws that hold the drum onto the hub? I've tried a big screwdriver held with a vise grip but that doesn't work. I can adjust my slacks just fine and the pads look ok from what I can see but I'd like to look at "S" cams, etc.
Fred

[Chopper Scott]

You'll veed an impact driver. They are fairly cheap. They will have flat and phillips attatchments and you put the largest flat screwdriver bit in it and whack it with a hammer. Go to the hardware store and get similar allen headed screws to replace them and put some antiseize on them when replacing them. To get the drum loose after removing the screws whack them with a 4 lb hammer and they will come loose. Hope that helps.

[luvrbus]

Fred, if you have a torch just blow the heads off, remove the drums and a little PB and a pair of vise grips they come out then replace with new ones if you desire they are not a necessity 1000's of buses don't have the screws any longer the wheel will hold the drum in place. 



good luck

[zubzub]

You can also remove the big  nut and bearing  and pull the front  hub off with the outer bearing without even removing the road wheel from the hub.  This is quick and easy but you should use new seals after.  I think the rears can be done this way as well,  dually still attached to hub, but you need to pull the half shafts, and getting it all together afterwards, clean and without damaging the seals sounds difficult.

[buswarrior]

If you don't know when the seals were done last, might as well do them now.

Some might argue the drum is easier to wrangle attached to the whole wheel/tire/hub assembly and then take it apart lying on the ground, where you can bear down, instead of across.

Lots of brake linings that are powder in the centre look fine from the edge you can see.

Good for you wanting to see the whole thing!

happy coaching!
buswarrior

[gus]

I just did this last weeend on my 4104 rear axle. first I used a huge screwdriver in each slot and hit the end of the screwdriver with a hammer a couple of times. The screwdriver has a solid shank all the way through the handle. I then found a slotted socket that was probably made for adjusting auto tie rods and ground it down slightly to fit the screw heads. Then I used a small half-inch 150 l-f air wrench with the socket and they easily came loose. I think it is too much of a job for a screwdriver because they need to be hammered if they have been on very long. Maybe a large screwdriver that fits tightly into the slots and allows use of a wrench at the end of the handle or on the shank will work, but I doubt it. It needs to be shocked loose.

I don't recommend using screws that have heads for allen wrenches unless the allen socket is very large, like for auto disc brake calipers. The bigger the screw slot the more torque you can put on it.

I plan to reinstall the original slot head screws with just a touch of antiseize on the threads. With the wheel disc over the screw heads there is no way they can come out and it doesn't matter if they are loose they aren't going anywhere.

That rear brake drum is heavy enough alone, I can't imagine trying to wrestle it off even with only the hub attached let alone with a wheel attached! It is hard enough to prevent new seal damage with the hub alone. I used a hyd lift table to install mine straight and level. The fronts are probably much lighter weight but that rear is a monster.


Absolutely replace the inner seal. The outer seal can be replaced without removing the hub or wheel. However, in the rear you will have to remove the axle, not a really hard job, at least in my case. That was probably the easiest part of the whole job!! The front only requires removing the hub cap.

Personally I would not remove the rear drum unless I had a really good reason. It was the hardest part of the disassembly, mostly because of its size and weight. Removing the lug bolts was easily the hardest part.

[Fredward]

hmmmmmm Heat wrench. I like the sounds of that. Might give it a try tomorrow night.

Those rear seals worry me. They don't leak but I hear all the stories of them just starting to leak and all the problems that follow. I'd like to get in there and get that all taken care of. I think i have a bad bushing on the passenger side "S" cam. Looks like some play in the shaft when the brake is actuated and then released.

Fred some people say derF .

[buswarrior]

Same concept gus, only you use a hydraulic bottle jack under the coach, and a sheet of metal under the tires to slide them on and off. Grease or oil up the metal and slide them off.

An old piece of galvanized duct work is what I have used, but any shiny piece of metal large enough will do.

A 5th wheel pin puller comes in handy to get a good pull, or a crowbar with the right bend on it.

Or, just give it a big hug and yank. Your goal is even application of the pull, pull on one side, the twist will hang it up, and you're fighting yourself.

The trick is getting the weight of the bus on the jack, the weight of the tire/wheel/hub assembly on the ground and off it comes.
Bus too high and the hub will hang, bus too low and the hub gets pinched.

Putting it back on, you just sight through the centre and adjust the coach for height.

This is a patient finesse job, as much as a force job. If you get the jack right, the rest is much easier.

Parked on the level, block the other wheels, back the brakes all the way off for clearance and put something under the axle, almost tall enough, but not quite, away from the jack, in case you goof.

Oh, and it would be good to remove all the fasteners and bearings from the centre before you try pulling...

happy coaching!
buswarrior

[gumpy]

derF,

Let me know if you need any help on those wheels.  I could swing by after work or come down one evening or this weekend.

The easiest I've found is a torch, a center punch, and a #4 Phillips screwdriver (unless your's are slotted).  I have a screwdriver that is
hex shaped and I can put a 7/16 wrench on it and get some good leverage. On the last bus I did, I heated the screw directly, and then put
the big screwdriver in it, smacked it a couple times with a hammer, and turned them out. A couple I had to use the center punch to start them.

craig