Front Brake Drum Removal MC5B

MCIGenes · September 06, 2013, 07:04:41 PM

Well, I am in the process of replacing the front Wheel Studs on my MC5B (Installing longer Studs for Alcoa Wheels and new tires. I would like to know if there is any easy way to get the drum seperated from the hub. I started with the driver's side and it was a bear to break the drum loose from the hub, but with the help of a special tool I built to hook on to the back side of the drum and a porta power spreader and a sledge hammer I got it off. Now I am working on the passenger side and I have the 5 screws out that hold the drum to the hub and even with all the prying and hammering it is not breaking loose. I was wondering if there are any usefull tips to make this task eaiser. Would it help to heat the drum where it contacts the hub?
I did the rear brakes and drums back a few months ago and they were a piece of cake compared to my front drums.
I do not want to damage anything by using the wrong process so I would like to know what method you have found usefull on MCI front drums & Hubs. Thanks in advance for any help you can give me.

Gene 1975 MC5B

bevans6 · September 07, 2013, 03:56:55 AM

You're on the right path, anyway. if you were to heat the face of the drum where it sits on the face of the hub, that might create some differential movement and break the rust free a bit. Otherwise a hammer on the face of the drum where the screws are, not on the rim of the drum, to break the rust grip. If you have a press you could take the whole thing off, by undoing the wheel bearing nut, put the drum and hub on the press and push on the studs to press the hub off the drum. You would have to change the hub seal, probably, which is always a good idea, but on the plus side changing the studs would be easier with the hub off the bus.

Brian

sommersed · September 07, 2013, 11:02:21 AM

On my 1967 5A, I just backed of the brake shoes, and was not bashful with the sledge hammer on the drums.

Ed

MCIGenes · September 07, 2013, 11:22:17 AM

Hi Brian,
Thanks for responding. Here is some more information on my goals. If I can not get the drum to break its grip on the hub any other way I will remove the hub and drum as one piece. But I was trying to avoid that because the seals and bearings were replaced at CJ in Minn in 2006. I suspect that they did not seperate the drum from the hub at that time. As for replacing the studs I built a Stud Press Tool several years ago that presses the stud out and then presses the new ones in while the hub is on the axle. It does not require removing the brake shoes or any thing else. My problem for right now is getting the drum out of my way. If I did not have the stud press that has worked so well in the past, then removing the hub would be the logical way to go. I will try the heat on it today and I probably have it off by tonight.
I replaced some studs in the drive axle last year and I had built a 4 ton stud press that worked good for the tag axle on my MC8. The hubs for the drive axle is thicker so I built a 10 ton stud press for the heavy axle. It worked like a champ on the drive axle so it should work even slicker on the front since the hub is about as thick as the tag was. Thanks again for your time and I will let you know if I am successful tonight.

chessie4905 · September 08, 2013, 07:04:34 AM

With a lot of sledge hammering, I'd want to remove bearings after and check them for any possible damage for peace of mind. Use good penetrating fluid and give it time to soak in. Reapply frequently, and use something better than WD-40. Does the drum have some threaded holes to help push drum off hub? If it does and you use them, use grade 8 bolts.

Dave5Cs · September 08, 2013, 06:06:12 PM

Chessie is right.
We busnuts are in no hurry!... We don't have to pickup riders at the next stop (any more?

) So put a little MOUSE MILK on it or PBB each day a few times and tap it with a single jack a few times. Then walk away or do something else on the coach.

When it is ready it will release. Lube, tap,tap, take a walk!...... When it breaks free it will be so much better and more ZEN meaningful.

Dave5Cs

MCIGenes · September 09, 2013, 09:57:14 AM

Well, I tried heating the drum with 2 toruches along with putting outward perssure with two devices and still no success. I do not want to damage the bearings so I decided to remove the drum & hub as a single unit. I drained the oil and then I did not have a 2.5" socket to remove the nut. I borrowed a socket from a friend, but I did not get time to work on it again that day due to other projects that needed my attention. When I did get a little spare time I took the nut off and ran into another problem. Inside the nut is a round cone that requires a special tool to turn it off the axle. So I started making a tool to remove it but I got pulled away again to do something for my wife. I finished welding it up last night, but it was dark so I did not go outside to use it on the bus. Today will be busy also but I hope to find time to see if my new tool works out. I rebuilt the rear hub about a year ago, but they were different than the front hubs.
I agree that I am interested in doing it without damaging the bearings and I only have about 2000 mile on those bearings and seals. God knows I have more than my share of other interests and projects to keep me busy. Besides if I ever run out of things to do I will sit down with autocad and desigen something to build. I will let you know when I get it finished.

MCIGenes · September 09, 2013, 02:17:11 PM

Well, I had some time this morning to work on the drum and I got the hub and drum off the axle without too much trouble. As it turned out I may have not needed to make the special wrench to remove the round nut, but it may help out when it comes to putting things together. I have a motorcycle jack on a furnature roller that I use to support the whole unit, and when it all slides off the axle, the weight is supported on the jack. I then rolled it into the shop and cleaned it up and put plastic cover on the inside end. I put the outside cap back on to protect the bearings. I then put the drum on a piece of plywood on the floor and blocked it up 2x4s so the hub had room to move downward. After putting some penitrating oil on the jount, I was going to let it set for a while but when I walked past the sledge hammer I decided to give it a quick test. I am going to replace the studs anyway so I was concerned about damageing them. I lightly hit the first stud and as I got to the 5th stud the hub dropped away from the drum. I will clean up the hub some more and replace some of the rusted bolts with stainless and then reinstall the hub back on the axle. I have a tool that I built to press the studs out when the hub is on the axle.

Gene

bevans6 · September 09, 2013, 04:52:11 PM

Congrats, good to see you getting it done!

Brian

mikelutestanski · September 10, 2013, 09:57:16 AM

Hello I had to replace a stud in south dakota I had to remove the hub because one of the screws would not release. THe stud came out with a hammer and chisel. putting the new one in was just getting it started and using a rattle gun to tighten it down to a seated position. I replaced the seal and regreased and was on my way.
SIne arriving home I decided to change all the front studs because the history of them was at least 20 years and not known before I bought the bus I had one front passenger stud break off and that questions the rest. SInce I do all the driving it makes sense to me to change the lot.
THe next question is drums.. DO I replace the drums if they show any heat cracks. ANy specs on that?
THe drums are webb 4003. The only replacement now is a webb 4003B which means balanced and is pricy. My price in florida at ABC is 218 each special order. SO it appears that the drums are getting obsolete..
BTW I have a 72 MCI 7 which probably has the same rockwell front axle as yours...
FWIW regards mike

chessie4905 · September 10, 2013, 10:55:44 AM

Coat the drum area where it contacts hub upon assembly with antiseize, after thoroughly cleaning with wire brush,wheel. Also coat screw threads and back side of flat head where it contacts tapered holes in drum. If you get new drums, check for oversize brake lining and on the shoes and rollers that ride on the brake camshafts. Your old drum could have been cut oversize in the past. Accurately measure drum id in several places and compare to original diameter. and max cut diameter.

bevans6 · September 10, 2013, 11:11:35 AM

Std. drum size is 14.0" ID by 5" wide, fwiw and to save you looking it up...

Brian