SOHC.co.uk Forums > CB350/400

Brake Drum Dust Seal

(1/2) > >>

Athame57:
I finally decided to fit the dust seal and washer for my rear brake drum. Alas, it caused so much trouble when I went to put everything back together I gave up with it. It was stopping me from getting the brake arm fit in a way that let the securing bolt pass through the recess in the brake shaft. Is this unusual, is it really important anyway? :-\

McCabe-Thiele (Ted):
As you will know the specially shaped washer is also a basic wear indicator,, the felt washer is to help keep out dust and water. Personally I think you should fit them both.

It's a fiddly job made difficult as the brake lever splines will be tight from the clamping of the bolt, worse if overtightened in the past. I would ensure the splines are clean on the shaft, rust free.

As you will have found out as you slide it in place the shaft moves into the hub. I had one of those tools that is like a screwdriver except it's a  pointed tapered end. I was able to push the tapered point into clamp bolt hole and this pulls the shaft out of the hub as the taper meets the bolt recess part of the shaft.

It might help to ease open the lever arm if it's a very tight fit in the shaft.
If they are available a new lever arm might be needed if it's been continually overtightened in the past,.

Athame57:

--- Quote from: McCabe-Thiele (Ted) on July 04, 2026, 08:05:50 AM ---
As you will have found out as you slide it in place the shaft moves into the hub.

--- End quote ---
That is exactly what happened Ted, I even wondered if this was a fault in itself. I'll have to find  something I can press into service to help with that.

K2-K6:
If its a felt seal (often the case from this era) it's ultimately to stop ingress of moisture by oiling the felt periodically. 

Stops them corroding from wet, road salt etc in the pivot, then seizing to stop brake working.

Much easier with wheel out as spindle can be supported from other side to push brake arm on.

The brake arm is ordinarily positioned with dots matching on arm & spindle to give correct system setup and adjustment range.

K2-K6:
There's often a "blank" spline area on the spindle to prevent the brake arm being moved incorrectly to another part of the tooth engagement too.

Prevents both wrong assembly position or someone trying to compensate for knackered shoes by moving the arm  :)

Navigation

[0] Message Index

[#] Next page