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Author Topic: Front Brake Gap  (Read 923 times)

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Offline Bido

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Front Brake Gap
« on: October 06, 2010, 06:29:20 AM »
I am having a problem with my front brake dragging it is a 1978 Supersport 750 I have gone thru the forum and have a question on the .006 gap should it be measured between the stationary pad and the rotor or from the caliper and rotor?
The brakes have been carefully rebuilt new stainless lines and new master cylinder the rotors have been surface ground and drilled.

Thanks Bido
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1978 CB750 Supersport F3
1981 CB750 K

Offline Skunk Stripe

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Re: Front Brake Gap
« Reply #1 on: October 06, 2010, 06:35:14 AM »
I think my manual says the gap is .008 between the "stationary" pad and the rotor. What you do is get the piston all the way back in and attach the caliper. From there, turn the adjustment screw for the mounting arm so that the stationary pad has the .008 gap. Then slowly squeeze the lever to close things up and then make sure air is bled out.

Oh make sure to clean a grease the pivot pin for the mounting arm and make sure the spring is clean too.
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Offline MCRider

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Re: Front Brake Gap
« Reply #2 on: October 06, 2010, 07:03:14 AM »
Quote from: Skunk Stripe on October 06, 2010, 06:35:14 AM
I think my manual says the gap is .008 between the "stationary" pad and the rotor. What you do is get the piston all the way back in and attach the caliper. From there, turn the adjustment screw for the mounting arm so that the stationary pad has the .008 gap. Then slowly squeeze the lever to close things up and then make sure air is bled out.

Oh make sure to clean a grease the pivot pin for the mounting arm and make sure the spring is clean too.
I'll confirm that in concept. 8thou seems a little big, but my context is pre-K3 at 5 thou I think. 8 thou could be it for later bikes.

Rather than "stationary", as its not really stationary, I like "dead" and "live", or master and slave, or A and B.

Just checked my manual and it says to tighten till the wheel won't turn, back off till it turns, then back off another 1/4 turn. So 8 thou could be it. And they just call it the "pad".
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Offline Skunk Stripe

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Re: Front Brake Gap
« Reply #3 on: October 06, 2010, 02:46:06 PM »
I used stationary mainly as a differentiating point between "stationary" side and piston side.
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Offline TwoTired

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Re: Front Brake Gap
« Reply #4 on: October 06, 2010, 03:02:50 PM »
I recommend you review the instructions in CB750 manual chapter 25 Supplement, section B, regarding the setup of the dual disk brakes found on the F2.  They have quite a different setup and adjustment procedure than the earlier single disk types.
I don't believe any of the previous advice given above applies to the F2 model.

Cheers,
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Offline Skunk Stripe

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Re: Front Brake Gap
« Reply #5 on: October 07, 2010, 06:38:43 AM »
right you are ken!
I checked my 78k/f manual and it actually does not say anything about adjustment in chapter 14.
Make sure you pushed the piston back in all the way when installing pads. Make sure the shims are installed with the arrow pointing up and then torque the caliper bolts. Otherwise, I guess there is a pad spring as well. So make sure the shim is seated correctly, check the pad spring and make sure the caliper is clean and the area behind the seal is clean. Use a very high temp silicon brake grease on the seal but be super careful to not get any on the pad.

Kinda strange there is nothing about adjustment but there are 2 bolts besides the caliper bolts. You might be able to adjust with these.
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