Author Topic: Master Cylinder replacement  (Read 2723 times)

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Offline Scott S

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Master Cylinder replacement
« on: April 02, 2010, 05:45:26 PM »
 Is there a suitable aftermarket master cylinder replacement available for a CB500/4? What is the stock bore so I can shop around?
 Is it worth rebuilding the stock M/C?
'71 CB500 K0
'17 Triumph Street Scrambler
'81 Yamaha XS650

Offline Johnie

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Re: Master Cylinder replacement
« Reply #1 on: April 02, 2010, 06:02:55 PM »
Fairly simple to rebuild the MC. Here is a pic of what the parts look like. The right half of the pic shows the kit I am installing. The left side just shows what I took out. The OEM kit for my 750 was about $40 from my dealer
« Last Edit: April 02, 2010, 06:04:38 PM by Johnie »
1970 CB750K0 - Candy Ruby Red
1973 CB750K3 - Candy Bacchus Olive or Sunflake Orange
1970 Chevy Chevelle SS396 - Cortez Silver
1976 GL1000 Sulphur Yellow

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Offline MoTo-BunnY

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Re: Master Cylinder replacement
« Reply #2 on: April 02, 2010, 06:37:59 PM »
Is there a suitable aftermarket master cylinder replacement available for a CB500/4? What is the stock bore so I can shop around?
 Is it worth rebuilding the stock M/C?

No offense, but I know this subject has been covered MANY times previously and those very informative posts surely can be found with just a bit of searching here on the forums?

Just using your own words, "master cylinder replacement" brought up three pages worth of previous posts:

http://forums.sohc4.net/index.php?topic=64178.0

http://forums.sohc4.net/index.php?topic=18045.0

http://forums.sohc4.net/index.php?topic=51070.0

http://forums.sohc4.net/index.php?topic=41098.0

http://forums.sohc4.net/index.php?topic=12934.0

http://forums.sohc4.net/index.php?topic=12664.0

http://forums.sohc4.net/index.php?topic=62759.0


etc, etc, etc. . . .  .

« Last Edit: April 02, 2010, 06:43:26 PM by MoTo-BunnY »
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Offline fastbroshi

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Re: Master Cylinder replacement
« Reply #3 on: April 02, 2010, 07:07:44 PM »
Is there a suitable aftermarket master cylinder replacement available for a CB500/4?

Yes, but lots of production bikes' master cylinders will readily switch over and work just fine provided they have the same thread for the banjo bolt. 

What is the stock bore so I can shop around?

I think it's 14mm, I may be wrong. 

Is it worth rebuilding the stock M/C?
Not to me, I just had a hell of a time getting mine apart!  That and the 1970s level of performance from the stocker have kept me from rebuilding it.  I'll be getting one of these soon (I have clubmans):
http://cgi.ebay.com/ebaymotors/FRONT-BRAKE-MASTER-CYLINDER-FZR750-FZR1000-XS650-XJ650R_W0QQitemZ120550349374QQcmdZViewItemQQptZMotorcycles_Parts_Accessories?hash=item1c115c5a3e

Or for standard bars, I've seen good reviews on this site for this one:
http://cgi.ebay.com/ebaymotors/FRONT-BRAKE-MASTER-CYLINDER-CB400-CB450-CB550-NIGHTHAWK_W0QQcmdZViewItemQQhashZitem1c115a45faQQitemZ120550213114QQptZMotorcyclesQ5fPartsQ5fAccessories

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Offline Scott S

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Re: Master Cylinder replacement
« Reply #4 on: April 03, 2010, 02:52:51 AM »

No offense, but I know this subject has been covered MANY times previously and those very informative posts surely can be found with just a bit of searching here on the forums?



 None taken. I do use the search function. One thing that cripples me is that many of the results come up in reference to CB750's (or a 400 or 350, etc). I'm working on a 500 and have yet to learn all the stuff that swaps over, interchanges, etc.
 Also, many of the threads in the search results are old and pictures and links no longer work, so they're not always as helpful as you'd think.
 I'm very new to the SOHC's and will probably continue to ask seemingly dumb questions. I will also continue to use the search.
« Last Edit: April 03, 2010, 02:59:46 AM by Scott S »
'71 CB500 K0
'17 Triumph Street Scrambler
'81 Yamaha XS650

Offline dave500

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Re: Master Cylinder replacement
« Reply #5 on: April 03, 2010, 03:09:09 AM »
i had to have mine sleeved,next time ill use some thing else,,if you dont need or want a genuine look,ill bet theres plenty of other options from most jap makes,even if the bore was smaller,it would only give you more pressure at the pad,for more stroke.

Offline mycb750k6

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Re: Master Cylinder replacement
« Reply #6 on: April 03, 2010, 05:39:26 AM »
I just re-anodized my MC in the back yard. Bought a 14mm flexi-hone per the book and put in the new guts. Brand new. My opinion the only things needing replacing in those kits are the rubber pieces. I wish I could find a place to just buy those. The springs, washer, valve, circlip all seem perfectly usable in a rebuild.

Oh by the way I noticed David Silver Spares juts starting selling a master cylinder for the CB750s. It doesn't look exactly stock but it's close (and brand new)

Offline Johnie

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Re: Master Cylinder replacement
« Reply #7 on: April 03, 2010, 06:37:44 AM »
If you do it yourself you will need a long cir-clip pliers to get that clip out. I just finished the MC and caliper rebuild on my KO, K1 & K4. What a nice difference. If you do it yourself be sure to get the Honda OEM kit and do not waste your money on the aftermarket stuff.
1970 CB750K0 - Candy Ruby Red
1973 CB750K3 - Candy Bacchus Olive or Sunflake Orange
1970 Chevy Chevelle SS396 - Cortez Silver
1976 GL1000 Sulphur Yellow

Oshkosh, WI  USA

Offline Gonzowerke

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Re: Master Cylinder replacement
« Reply #8 on: April 03, 2010, 07:11:35 AM »
If you are not concerned about stock looks, the MC from an early 90's CBR600F works real good. It is what FrankenBike is wearing. The rebuild kit was cheaper too...
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Offline Zaipai

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Re: Master Cylinder replacement
« Reply #9 on: April 03, 2010, 07:17:40 AM »
I am doing this to mine, thanks for the links very helpful!!!

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Offline fastbroshi

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Re: Master Cylinder replacement
« Reply #10 on: April 04, 2010, 11:05:30 PM »
If you are not concerned about stock looks, the MC from an early 90's CBR600F works real good. It is what FrankenBike is wearing. The rebuild kit was cheaper too...

That right hand button pod works great too, but you can't use the throttle tube.  No big deal, because a 550 tube works perfectly in there.  Just get yourself a wiring diagram for the 600 and once wired up it works okay.  It also has female leads off of it for a mc with a brake switch on it, like the ones I linked to.
Just call me Timmaaaaay!!!