Cafe Racer Forum banner
1 - 7 of 7 Posts

·
Registered
Joined
·
10,654 Posts
Discussion Starter · #1 · (Edited)
So now I assume that you would like to rebuild the brake system that you bought to do the twin piston caliper upgrade I posted about. Makes total sense to rebuild them before you install them. Means that your whole system is functioning perfectly.

Good thing is that Honda still makes 99% of the needed parts.
Clear off a nice place to work.

Points for knowing the engine…..

Teardown:

Try and keep the brake fluid in check. Not to keep the ice caps cold or the polar bears white, but because that junk will eat paint and cause a mess.

You need to take the sliders out as well as the rubber boots. Replacing these does add up, but I think it is worth it.
On most of the calipers that I have taken down the pistons slide out fairly easily.


If the pistons do not slide out there are a few things you can do.
-Try and use a functional master to drive the pistons out.
-Use a little heat to free everything up.
-If all else fails you can use a grease gun or compressed air.

Once everything is apart make sure you clean everything thoroughly. Make sure you take extra care to clean the piston seal groves well. They tend to get a gunk built up that makes the new seals hard to seat.


I send most of my calipers off for powdercoating.


Install the new piston seals and pistons. About the only thing I ever use that isn’t OEM are the actual pistons. Some are cheap from Honda, but there are a few stainless options that are even cheaper. While I do tend to over service by buying new "springs" that hold the pads and the other clips for the calipers, its only money....



Might want to think about replacing the small/thin pad holders. In the previous picture you can see the one that holds tension on the pads. In the next picture you can see the shim that helps with caliper to mount positions.

Other area to think about servicing is the bolts that the calipers side on. They need to be removed and cleaned. When installing make sure you use a quality grease. The boots that protect these parts are readily available from Honda still. I would really recommend replacing the boots as they tend to get shitty over time and rip when removed.

Masters:

These are fairly simple to rebuild. About the same as the calipers. There is a Honda tool that MotionPro sells that makes life a little easier. It is a pair of snap ring pliers with a very long nose. This gets deep into the master to get the snap ring that holds everything together out. Front and rear are basically the same process.

For my bike I ran a CBR600F2/3 front master. If you want to change your master make sure that you understand how the ratio of piston area to master size works. http://www.vintagebrake.com/mastercylinder.htm has a great chart that can help you in picking a master for your application.


One thing that comes up from time to time is the sight window in the master is hazed over. This is mostly a cosmetic thing as long as it isn’t leaking.
I have a “top tip” to fix this issue.
With some poking, cutting, pushing and general force the sight window can be removed.


Watches use a mineral glass as the face. It is strong, made well and resistant to chemicals. It makes a great replacement for the faded plastic.


You will have to measure what size glass you need for your master.
I have used this place to get the needed glass before. They have a minimum order so it might be something to order with friends or something.
REGULAR FLAT MINERAL GLASS

Bonus Options:

Honda still makes the brake switch that activates the brake lights. I tend to over service and have replaced working switches just for piece of mind.

 
  • Like
Reactions: Geeto67

·
Registered
Joined
·
10,654 Posts
Discussion Starter · #4 ·
Yup, VR6.
I have a MKV R32 and have helped friends build a few turbo VRs.

- - - Updated - - -

just a warning about using heat.....make sure you don't do that if you've tried spraying brake cleaner to loosen anything. fumes are seriously toxic once heated. probably not a good idea to heat brake fluid either though i believe not as serious as burning the cleaner.

read this a while back...

Safety Alert! Brake Cleaner = Phosgene Gas - BREW Bikes LLC

Agree 100%
Shop safety should always be in your mind.
 

·
Registered
Joined
·
10,654 Posts
Discussion Starter · #6 ·
I have used a few places for the pistons. I should work on getting the Honda part numbers dug out and put in this thread. If you play "the part number game" you can save a few bucks.

So far I have used
-Ebay sellers
-A guy on SOHC4. Would have to dig to see who
-SUDCO
-And various on line resellers.

Honestly I am a cheap fuck with this type of thing. I know the part numbers I need, so it all comes down to who has it cheapest when I need it.
 

·
Registered
Joined
·
10,654 Posts
Discussion Starter · #7 · (Edited)
For the calipers that use the 30mm pistons like the stock 1982 CB900F that this swap was based on the pistons, seals and all that is needed to service these are still available from Honda.
I ALWAYS use OEM seals, but have been known to use aftermarket pistons. The part numbers for the seals are 45109-166-006 and 45209-166-006, to do the front pair of calipers you will need 4 of each.They run like $4 each. The OEM number for the pistons is 45107-MA3-006 and this runs about $30. If you want Sudco has them for about $20 under part number 603-004. Obviously you will need 4 pistons to do a pair of calipers. I have had great luck by crossing those part numbers for the pistons across many different retailers.Almost seemslike the price changes based on the bike it is listed as fitting. And since Honda used these parts in millions of motorcycles it is fairly easy to get the needed parts.
For those that are using the 32mm piston calipers off a V65 or something else the prices don’t change that much on anything. For the pistons the part number is 43107-MA7-006 and 603-003 for OEM and Sudco respectively. Seals are 4509-MA7-006 and 45209-MA7-006

In red you can see the seals and pistons. I highlighted yellow the dust boots for the sliders that I also normally change.
 
  • Like
Reactions: Geeto67
1 - 7 of 7 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top