Author Topic: Rear Brake Pedal Adjustment  (Read 438 times)

Offline SeanFD

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Rear Brake Pedal Adjustment
« on: October 12, 2023, 02:13:19 PM »
I'm almost there ... almost!

I posted by mistake on the US site, but they'll all be in bed still, so apologies for this getting a double post.

I'm trying to adjust the rear brake pedal and spring. The first issue is that the pedal either sits too high or hits the exhaust when depressed.

Looking at the return spring, and having seen several related posts, it all looks to me a bit loose; the spring that is. I have the spring positioned as in the photos, which I think is correct.

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The first photo is with the actuator rod loose to show the position of both ends of the spring (one covered by rubber tube) and the second is with the rod "tight".

Can anyone confirm the spring is correctly located and then advise how to position the brake pedal, using the split in the lever as a reference; I currently have it at about 10 o'clock.

Thanks.
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Offline Oddjob

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Re: Rear Brake Pedal Adjustment
« Reply #1 on: October 12, 2023, 02:22:19 PM »
On the brake pedal, where the brake pivot shaft passes through, will be a punch mark. On the shaft itself is another punch mark, these line up. When you do that the pivot shaft arm where the spring is located will be forced forward, putting the spring under a lot more pressure.

So to fit, line up the punch marks, push the rod forward so the pivot arm moves forward and slide the brake lever on, this will force it under the brake lever adjusting bolt on the frame so keeping it down. Then make sure the brake lever on the drum also has it's punch mark aligned with the brake pivot pin punch mark and everything should fit fine.

That make sense?
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Offline SeanFD

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Re: Rear Brake Pedal Adjustment
« Reply #2 on: October 12, 2023, 06:16:41 PM »
It makes perfect sense. The trouble is the dots have been covered by powder coating. I can see only one dot on the brake cam and one on the brake pedal  :(

Anyway, I adjusted here and there and seem to have got it working adequately; until I have the chance to road test.

I think it's looking good

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Considerably better that before anyway:

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Now I just have to get it running; I failed this afternoon  :(
« Last Edit: October 12, 2023, 06:18:30 PM by SeanFD »
CB750 K2 - Ridden from Belfast(SA)-2-Belfast(NI)!
CB750 K1 - The less, said the better!
CB450 K1 - A work in progress.
CB400F Supersport - Rusty - not any more!

Offline Oddjob

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Re: Rear Brake Pedal Adjustment
« Reply #3 on: October 12, 2023, 07:36:47 PM »
To check, if the brake rod is protruding from the brake arm on the brake plate by about 10mm then the front is approx in the right position. Providing of course the brake arm is correctly positioned on the brake cam in the brake plate.
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Offline SeanFD

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Re: Rear Brake Pedal Adjustment
« Reply #4 on: October 12, 2023, 08:36:12 PM »
🤣🤣 Now that is confusing ; rod, arm, plate, cam ....

I take it that 10mm is measured before turning the adjusting nut on the rod
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CB450 K1 - A work in progress.
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Offline McCabe-Thiele (Ted)

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Re: Rear Brake Pedal Adjustment
« Reply #5 on: October 12, 2023, 08:53:22 PM »
I had a similar issue as you regarding the missing dot marks thought I did eventually find a feint mark on the front brake pivot although my aftermarket pedal did not have a dot.

I worked from the rear brake shoe pivot where the rear lever fits going  forwards eventually finding the right amount of leverage to position the brake pedal lever something close to where it should be.

I initially had insufficient thread on the rear adjuster nut so ended up with a compromise that was finally resolved when the new rear brake linings had bedded in, I had a full thread into the nut after a 100 miles or so when adjusted again.
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Offline Oddjob

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Re: Rear Brake Pedal Adjustment
« Reply #6 on: October 12, 2023, 11:29:37 PM »
Yeah, about 10mm protruding through the dowel that fits inside the rear brake arm.

Arm rear, lever front.
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