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  View original topic: New rear brakes, bearing cap woes...
danielzink Wed May 22, 2019 11:49 am

Working on a friends "1960" (Brazilian) bus...

The rear brakes were soaked in gear oil on one side and had a failed brake cylinder on the other (soaked w/brake fluid).

I purchased new shoes and drums (CIP1) as per the part numbers on the existing drums.

Everything went together well until it came time run the axle nut down on the new drums.

Upon torquing the nut down the axle would "lockup"...hard.

no rotation.

It took a little ciphering but I finally figured out what was going on once I slid the old drum on and proceeded to torque and everything was fine.

Here is a pic of the new drum vs old:









Note the width of the "seating" area.

The new drums were ordered (and came in) as the part number cast into the old drums...

What's happening is that the flat area on the new has a larger diameter than the old drum and it's not fitting inside the old bearing cap...it's sitting *on top* of it.


I have a variety of bearing caps hanging around so I decided to pull them out and do some "comparing"...




What I figured out is that the majority of these caps will fit around the new drums.




The problem is that these are all 311 (type 3) part number caps.

ANother issue I found is the "depth" of the stock 211 caps:




I only have one 311 cap that is the same depth as the 211 (left hand cap)




Even though they all have the exact same 311.501.311A part number...one is significantly deeper than the others..




Should I try and source a 2nd "deep" 311 bearing cap...install them and be done ?

Anyone have this is previously ?

I did search but my search-fu skills didn't come up with anything that stood out...

Thanks, Dan

ToolBox Thu May 23, 2019 9:14 am

That is about a six pack to your local machinist away from fitting correctly. I would first check the drum and make sure they are dimensionaly correct in all other ways.

Eric&Barb Thu May 23, 2019 9:35 am

Agreed, would measure the drum in many ways, and if that is the only problem, either fix it yourself or at a machine shop.

69aircooled Thu May 23, 2019 9:58 am

I agree with toolbox and E&B. Should be an easy job for a local machine shop. First just make sure other dimensions are correct/same for both axles and drums.
Too bad the drums are out-of-spec in that area in the first place. You should inform your supplier.



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