82 650SC Brake Caliper piston: Updated with interchange info

If it's broken or just needs tweaked

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MiGhost
Posts: 379
Joined: Tue Jun 07, 2011 2:30 am
Location: South Central Mitten

82 650SC Brake Caliper piston: Updated with interchange info

Postby MiGhost » Mon Jul 01, 2013 2:14 am

Gathering the pieces to do a dual disk, twin piston brake upgrade using the 81 custom forks/rotors with 82 nighthawk calipers.

All the info that I find on the twin piston calipers used by honda is that they use either the 30mm X 35mm piston, or the 32mm X 35mm piston.

The 82 standard along with the 83-85 nighthawk use the 30X35 pistons. These are still readily available. My problem is locating information on the piston size for the 82 nighthawk calipers.

Can anyone confirm the correct size for the 82 CB650SC nighthawk brake caliper pistons?
Or know where I can find the correct pistons?
Last edited by MiGhost on Thu Nov 28, 2013 9:26 pm, edited 2 times in total.
~ Ghost

PD50 Carb Info
82 CB650SC Brake Caliper Info

Stable
Wayward Son:1980 CB650C, RestoMod Period Custom Touring
Bad Moon: 1983 XJ750MK Midnight Maxim, Full Dress Tour Deluxe w/ X-1 Fairing
Nemesis: 1983 XJ750K Maxim, Old School style chopper

MiGhost
Posts: 379
Joined: Tue Jun 07, 2011 2:30 am
Location: South Central Mitten

Re: 82 650SC caliper piston ???

Postby MiGhost » Thu Jul 04, 2013 11:25 pm

After doing further research using the K&L Caliper reference. The following pistons are used in the twin piston calipers
K&L# . . Size
32-1174 32 x 35mm
32-1176 30 x 35mm
32-4187 26.96x35.04mm
32-2304 27 x 25mm

The 32-1174, and 32-1176 are used in the front, and rear calipers.
The 32-4187 is most commonly used in the rear calipers.
The 32-2304 is most commonly used in the dual sport/dirt calipers. (Not used on any bike prior to '87)

Not comming up with a clear id on the pistons. I measured the diameter of a piston in the set of used calipers I have, and came up with a measurement of 26.95mm Dia. This directly corresponds with the 32-4187 piston used in the calipers of the honda rear disc brake setups.

As the 32-4187 piston is the only one available with a diameter of 26.96mm from any manufacturer. I must conclude that this is the correct piston for these calipers.

Brake Caliper Piston Interchange 1982 CB650SC
K&L 32-4187 BCP-114 26.96x35.04mm

45107-460-841 PISTON
1982 CB650SC A FRONT BRAKE CALIPER

43107-MA3-006 PISTON
1981-82 CB750F A REAR BRAKE CALIPER
1981-82 CB900F A REAR BRAKE CALIPER
1983 CB1100F A REAR BRAKE CALIPER
1981-82 CBX A REAR BRAKE CALIPER
1987-90 CBR600F A AC REAR BRAKE CALIPER
1987-88 CBR1000F A AC REAR BRAKE CALIPER
1993-96 CBR1000F A AC FRONT BRAKE CALIPER
~ among others

Once I have the seals in hand. I will pull the piston out of the caliper to confirm the height. As the height is not likely to exceed the 35mm measurement. Any excess piston height can easily be milled/turned off by a machinist if necessary.
Last edited by MiGhost on Wed Nov 27, 2013 10:17 pm, edited 1 time in total.
~ Ghost

PD50 Carb Info
82 CB650SC Brake Caliper Info

Stable
Wayward Son:1980 CB650C, RestoMod Period Custom Touring
Bad Moon: 1983 XJ750MK Midnight Maxim, Full Dress Tour Deluxe w/ X-1 Fairing
Nemesis: 1983 XJ750K Maxim, Old School style chopper

cmouta
Posts: 74
Joined: Tue Aug 14, 2012 8:23 am
Location: West Haven, CT

Re: 82 650SC caliper piston ???

Postby cmouta » Thu Jul 11, 2013 8:15 am

I've got some loose pistons at home that I can grab on my lunch break and measure the height on. I went through a similar problem where I couldn't pull the frozen pistons so a coworker practically destroyed them trying to pull them for me(of course now I know all the cool tricks) and I ended up having to buy a used set of calipers on ebay because of lack of replacement pistons. Great research, thanks!
Chris

1982 Candy Flair Blue Honda CB650SC Nighthawk
2006 Bajaj Chetak 4T with scooterworks usa sidecar
2013 Fiat 500C Abarth
1988 Mono Rosso Red Merkur XR4Ti T5 MT

MiGhost
Posts: 379
Joined: Tue Jun 07, 2011 2:30 am
Location: South Central Mitten

Re: 82 650SC caliper piston ???

Postby MiGhost » Thu Jul 11, 2013 5:27 pm

If you could measure the pistons you to confirm the height. That would be great.

It its not unusual for manufacturers to use the same part under more than one part number. I am find that a lot of the parts that are no longer available for the 650's have an interchangable counterpart in the 750's. Some times it is a pain to figure out the interchange information though.
Last edited by MiGhost on Wed Nov 27, 2013 10:16 pm, edited 1 time in total.
~ Ghost

PD50 Carb Info
82 CB650SC Brake Caliper Info

Stable
Wayward Son:1980 CB650C, RestoMod Period Custom Touring
Bad Moon: 1983 XJ750MK Midnight Maxim, Full Dress Tour Deluxe w/ X-1 Fairing
Nemesis: 1983 XJ750K Maxim, Old School style chopper

cmouta
Posts: 74
Joined: Tue Aug 14, 2012 8:23 am
Location: West Haven, CT

Re: 82 650SC caliper piston ???

Postby cmouta » Fri Jul 26, 2013 4:09 pm

Sorry for the delay. I just measured one of my brake pistons (keep in mind they were slightly polished by one of my machinists at work and I think he took too much off and it caused leaking, maybe?) but I measured the height at 1.240" = 31.496mm and the radius at 1.0575" = 26.8605mm.
Chris

1982 Candy Flair Blue Honda CB650SC Nighthawk
2006 Bajaj Chetak 4T with scooterworks usa sidecar
2013 Fiat 500C Abarth
1988 Mono Rosso Red Merkur XR4Ti T5 MT

MiGhost
Posts: 379
Joined: Tue Jun 07, 2011 2:30 am
Location: South Central Mitten

Re: 82 650SC caliper piston ???

Postby MiGhost » Thu Nov 28, 2013 9:24 pm

UPDATE: Interchange Information

Here is some interchange info for rebuilding the 82 CB650SC front brake calipers.

Notes:
*= old obsolete part #'s as used on the 82 CB650SC calipers
+=new interchange part #'s
Numbers following */+ indicate item number on given schematic links
Numbers in () indicate quantity needed per caliper

*Year: 1982
Model: CB650SC A
Component: FRONT BRAKE CALIPER
http://www.partzilla.com/parts/search/H ... parts.html

+Year: 1982
Model: CB750SC A
Component: FRONT BRAKE CALIPER
http://www.partzilla.com/parts/search/H ... parts.html

*20: 45224-413-003 VALVE, BLEEDER (1)
+1: 43352-568-003 SCREW, BLEEDER (1)
Part# 43352-568-003

*7: 45108-425-003 CAP, BLEEDER VALVE (1)
+2: 43353-461-771 CAP, BLEEDER (1)
Part# 43353-461-771

*6: 45108-MA5-771 SPRING, PAD (1)
+8: 45108-MA3-006 SPRING, PAD (1)
Part# 45108-MA3-006

*10: 45111-MA5-771 SLEEVE (1)
+11: 45111-MA3-006 SLEEVE (1)
Part# 45111-MA3-006

*12: 45133-MA5-771 BOOT, PIN (1)
+15 45133-166-016 BOOT, PIN (1)
Part# 45133-166-016

*13: 45134-MA5-771 BOOT, BOLT (2)
+16: 45133-MA3-006 BOOT B (2)
Part# 45133-MA3-006

*18: 45215-MA5-771 PIN, PAD RETAINING (2)
+21: 45215-MA3-006 PIN, HANGER (2)
Part# 45215-MA3-006

*19: 45217-MA5-771 PLATE (1)
+22: 45217-MA3-006 PLATE (1)
Part# 45217-MA3-006

+Year: 1982
Model: CB900F A
Component: REAR BRAKE CALIPER
http://www.partzilla.com/parts/search/H ... parts.html

*5: 45107-460-841 PISTON (2)
+4: 43107-MA3-006 PISTON (2)
Part# 43107-MA3-006

Note: As noted in above discussion. The pistons may be taller in height, and require adjustment by a machinist to function properly. The overall diameter will work.

SEALS:
The required seals to rebuild the calipers are still available through honda.

8: 45109-460-841 DUST SEAL
16: 45209-460-841 SEAL, PISTON
~ Ghost

PD50 Carb Info
82 CB650SC Brake Caliper Info

Stable
Wayward Son:1980 CB650C, RestoMod Period Custom Touring
Bad Moon: 1983 XJ750MK Midnight Maxim, Full Dress Tour Deluxe w/ X-1 Fairing
Nemesis: 1983 XJ750K Maxim, Old School style chopper


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