brake drum inspection

[Larry B]

Good evening everyone-- first thing before I start asking questions I would like to wish each of you a Merry Christmas and all the best to each and your family in the New Year.  i have a1978 MCI 5b On the last outing (when heading home )as I released the park brake , the first few revolutions of the rear tires made quite a noticible "BUMP" as the tire came around to a certain spot. After about three tire revs. it stopped doing this. 30 miles to home drive slow and hope for best. No more bump-bump. You where able to feel this while sitting drive seat when it happened. I removed rear tires and drums to inspect I needed to know cause. I had had a rock between drum and shoe. A small grove on drum and a little corner piece missing on one shoe. If you look at picture that pice of rod is 3/8". Is there any reason I should not close that gap between drum and rock sheild down to about an 1/8" ?  Also determined I was over greasing my S cam shaft and bottom brake shoe hinge points. Too many gobbs of grease ready to fall on inside of drum. Did a good clean up and put back together.  Did an inspection on air hoses while it is nice and open and ease to get at. Going to change all hoses.  If you notice in the picture my brake pot is off. Two of the three hoses touch things on this pot (shock and air bag). I want to orientate the sections of the pot so hoses will move away from air bag and shock. I read through maintenance  manual sounds to be a simple task. Is there aanything I should be aware of before I tackle this? Have heard rumors about people needing partial plates (teeth) after playing with brake pots. Getting too old for that kind of action. Brake pot is in release position (push rod retracked) before starting task. Thanks
       Larry B   

[Stormcloud]

I would close that gap to about 1/8"  As long as it doesn't rub at all, there should be zero problem...
and it may keep those tiny stones out.

[lostagain]

I just R & R my DD3s. Read the   procedure  in the manual first. You don't  even have to take them apart. Just loosen the clamps and rotate the body parts to where you want
them. But since there are on the bench now, might as well go all the way and disassemble


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[lostagain]

Clean up, inspect and re grease. Then you know they're good


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[Larry B]

  Thanks guys ---now I have something to do tomorrow.
             Larry B

[Dave5Cs]

Larry just remember that parts are almost fully made from unobtaium for DD3's now. Some just buy new ones but they are 400.00 on up.

Dave5Cs

[TomC]

I don't like dust shields on my brakes. Once dust or a rock gets in, it is very hard to get it back out, except to take it apart. As compared to no dust shields-if dust, or rocks get in, they will quickly shoot back out when the bus gets up to speed. Neither my bus or my truck have dust shields. And all new trucks that I order do not have dust shields either. I would just plainly remove them. Good Luck, TomC

[eagle19952]

I don't like dust shields on my brakes. Once dust or a rock gets in, it is very hard to get it back out, except to take it apart. As compared to no dust shields-if dust, or rocks get in, they will quickly shoot back out when the bus gets up to speed. Neither my bus or my truck have dust shields. And all new trucks that I order do not have dust shields either. I would just plainly remove them. Good Luck, TomC

In most instances I would agree.
It appears (to me) that someone added those rock guards, they do not look correct, or like the ones that any manufacturer would have spec'd...the lips on those vary and those are not right.... the attaching bolt pattern is pretty much the same on most axles, the offset is not.
I would rather have none than those.

[bevans6]

I am 99% sure my MC-5C doesn't have those guards on it.  FWIW.  I know my annual inspection guy appreciates that!

Brian

[Jim Eh.]

Not only do dust shields keep small rocks in, they also cause heat retention and missed oil seal leaks. For any of those who run their bus into freezing weather and have dust shields, don't apply your parking brake (if you can at all help it) until your brake drums have cooled. Breaking the shoes free with shields on is a PITA.

[Larry B]

  I got the DD3 pot apart and reassembled with different orientaion looks much better. Two more hoses to go and will have all new hoses. During my many trips in and out from under the bus I kept looking at these shields trying to figure an easy way to close the gap to keep rocks out. I like the idea of removing better than fixing. The rock can go out the same way it got in ---out the big hole. Makes sense. With the shields on , I did not know I was over greasing the brake shoe hinge points. same effect as a leaking seal on brake pads. With them off I can do my own inspection and not have to remove tires and drums to look inside. Thanks again.
        Larry B

[eagle19952]

With them off I can do my own inspection and not have to remove tires and drums to look inside....
If it were mine, AND I located a proper set, that did the job they were intended to do, I would put them on, especially if I traveled the unpaved parts of the Alcan Hwy <which I have and do>.

Breaking the shoes free with shields on is a PITA...
Not really, there are only (usually) 3ea 5/16 bolts that hold them on....
And with a weed burner/tiger torch, a bottle of propane, a sledge hammer and a few sections of stove pipe with a 90* you can thaw out frozen anything in about 5 minutes....
For me, I would not travel above the 49th parallel in winter without one.

[Jim Eh.]

Breaking the shoes free with shields on is a PITA...
Not really, there are only (usually) 3ea 5/16 bolts that hold them on....

After 30+ years of moving trailers in from out in the cold, I beg to differ. Easy with a spoke hub but with a disc hub, meh.
Dust shields have always been a personal preference with my customers and will always be a subject of debate.

[eagle19952]

After 30+ years of moving trailers in from out in the cold, I beg to differ. Easy with a spoke hub but with a disc hub, meh.
Dust shields have always been a personal preference with my customers and will always be a subject of debate.

Apples and oranges....20-40 year old coaches don't have disc brakes...After 40 years in the Arctic moving multitudes of heavy construction equipment and all peripheral support in and out of service in extreme cold conditions I beg to differ also...but will agree to disagree.
PS time is money .. portable heat is my friend.