Author Topic: Early CB 750 Rear brake arm  (Read 1194 times)

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Offline major domo

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Early CB 750 Rear brake arm
« on: August 23, 2016, 10:26:15 AM »
I'm having trouble getting the rear brake arm back onto the shaft splines on a 1970 CB750. I'm not sure if this is the correct arm, as a photo in John Wyatt's book (page 51) "Original CB750" seems to show an arm that is very straight, while mine  has a  slight curve to it. The one in the book also looks a bit thinner.  If I recall, this arm came off very easily when I dis-assmebled the brake drum many months ago; maybe it was only partially on the splines? The finish is also rough on the inside of the arm, with what appears to be a number/mark cast in it.  I've attached photos of the arm I have.  Any comments welcome!
« Last Edit: August 23, 2016, 11:07:17 AM by major domo »

Offline flybox1

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Re: Early CB 750 Rear brake arm
« Reply #1 on: August 23, 2016, 10:35:10 AM »
brake arms from K0-K5 all reference the same part # 43410-341-700
cant say that yours is incorrect tho  :-\
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Offline 754

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Re: Early CB 750 Rear brake arm
« Reply #2 on: August 23, 2016, 11:44:08 AM »
It should not push on with your fingers, a light tap with a block of wood and hammer...with cam supported should do it with ease......make sure spline is oriented correctly..
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Online madmtnmotors

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Re: Early CB 750 Rear brake arm
« Reply #3 on: August 23, 2016, 11:56:10 AM »
make sure spline is oriented correctly..


+1

Sometimes a screwdriver in the gap on the end of the arm will open it up and provide some relief. Don't use a big hammer, just tap the screwdriver into the gap with the heel of your hand, it shouldn't take much, then see if it will go into place.
TAMTF...


Wilbur



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Offline DaveBarbier

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Re: Early CB 750 Rear brake arm
« Reply #4 on: August 23, 2016, 12:21:56 PM »
Obviously make sure splines on both parts are clean. Also, don't try to put the lever on with the bolt in place. :))

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Re: Early CB 750 Rear brake arm
« Reply #5 on: August 23, 2016, 01:12:09 PM »
Also, don't try to put the lever on with the bolt in place. :))

BTDT!  :o
TAMTF...


Wilbur



Projects:
"Evolution": http://forums.sohc4.net/index.php?topic=100352.0
"P.O. Debacle": http://forums.sohc4.net/index.php/topic,126692.msg1441661.html#msg1441661
F2/F3 O-rings: http://forums.sohc4.net/index.php?topic=113672.msg1300721#msg1300721
Cam Tower Studs: https://www.mcmaster.com/#93210a017/=t19sgp
Clean up that nasty harness: http://forums.sohc4.net/index.php?topic=137351.msg1549191#msg1549191
http://forums.sohc4.net/index.php/topic,148188.msg1688494.html#msg1688494
http://forums.sohc4.net/index.php/topic,139544.msg1579364.html#msg1579364
                                          
Charging system diagnosis: http://forums.sohc4.net/index.php?topic=1012.msg8345#msg8345
Get the manuals: http://manuals.sohc4.net/cb750k/
The Dragon: http://forums.sohc4.net/index.php?topic=45183.msg1571675#msg1571675
Headlight Switch: http://forums.sohc4.net/index.php?topic=113986.msg1283236#msg1283236
Branden's leak free top end thread: http://forums.sohc4.net/index.php?topic=107040.0
Engine Lifting Made Easy: http://forums.sohc4.net/index.php/topic,58210.msg1684742.html#msg1684742
                                      http://forums.sohc4.net/index.php/topic,100352.msg1675840.html#msg1675840
Static and Dynamic Timing: http://www.hondachopper.com/garage/carb_info/timing/timing1.html
Airbox Gasket Replacement: http://forums.sohc4.net/index.php/topic,114485.msg1290000.html#msg1290000
"Café" : http://forums.sohc4.net/index.php/topic,84697.msg953814.html#msg953814
PD Carb Choke Linkage: http://forums.sohc4.net/index.php/topic,100352.msg1669248.html#msg1669248
                                    http://forums.sohc4.net/index.php/topic,110931.msg1248354.html#msg1248354
                                    http://forums.sohc4.net/index.php/topic,48858.msg515204.html#msg515204
Follow up on your damn posts: http://forums.sohc4.net/index.php/topic,144305.msg1791605.html#msg1791605
Taiwanese Cam Chain Tensioners:  http://forums.sohc4.net/index.php/topic,155043.msg1774841.html#msg1774841
Gumtwo Seat Cover: http://forums.sohc4.net/index.php/topic,164440.msg1897366.html#msg1897366
Primary Drive: http://forums.sohc4.net/index.php/topic,166063.msg1919278.html#msg1919278
Tank Latch: http://forums.sohc4.net/index.php/topic,165975.msg1919495.html#msg1919495
Shorten your forks: http://vintage-and-classic-honda-s.456789.n3.nabble.com/How-to-shorten-forks-td4042465.html DO NOT CUT THE SPRINGS!
Clutch How To: http://vintage-and-classic-honda-s.456789.n3.nabble.com/How-to-change-and-adjust-a-clutch-SOHC-td4040391.html
Late model K7/K8/F2/F3 front sprocket cover removal: http://forums.sohc4.net/index.php/topic,178428.msg2072279.html#msg2072279
630 to 530 conversion: http://forums.sohc4.net/index.php/topic,180710.msg2094423.html#msg2094423

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Offline major domo

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Re: Early CB 750 Rear brake arm
« Reply #6 on: August 24, 2016, 09:51:10 AM »
The brake arm will not tap on with a hammer or mallet. I've been told that the brake arm shaft has an area where there are no splines, and that should match up with an area on the brake arm for correct installation. This brake arm shaft has splines all around.

Offline somesuch

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Re: Early CB 750 Rear brake arm
« Reply #7 on: August 26, 2016, 06:47:03 AM »
The brake arm will not tap on with a hammer or mallet. I've been told that the brake arm shaft has an area where there are no splines, and that should match up with an area on the brake arm for correct installation. This brake arm shaft has splines all around.

This is what my experience has been....there usually is marker dot on the shaft as well to make the alignment easier