Topic: Brake caliper/pad help

[Nicholosi]

I have a cobbled together cb750. Started as a box of parts. Rebuilt topend, went through carbs , etc. Cranks right up and runs great (after one more adjustment to the floats). Problem is no two parts came off the same bike. Motor is a '75, frame is a '77, etc., etc.

 So i'm not sure what front caliper i have. The old pads while thick enough, were actually starting to crumble, so replacement was in order. Cleaned the caliper up real good and was planning on re-using the seal. Now for the problem, I have no idea what year this caliper is off. I bought pads for a '75. They are 50mm O.D. which is slightly too big. Any ideas? I can measure the old pads tonight but thought somebody here might have an idea.

One more thing, it looks like the caliper might be off a bike with dual front discs. I'm basing this on the fact that the hole for the bleeder screw is the same size and thread as the one for the hose feeding fluid to the caliper and on the 550 (single caliper , obviously) the two holes are different sizes.

Sorry for the long post, thanks for any help you can provide, and great sight. Even though this is my first post, you guys have helped me tons in the last few weeks.

[Bob Wessner]

Depending on the age, reusing the seal might be questionable. What shape is the piston in? If it has any pitting, it should be replaced also.

[alfabeast]

Sounds like you have an early caliper, they had two holes both with 10mm x 1.25 threads, I know for sure that <K2 has this style
You may have the pads for the later caliper from the 77k or 78K, they look like your 550 and have a 10 x 1.25 for the hose and a 7 x 1mm for the bleed nipple

[alfabeast]

Also....the seals on the honda caliper are so beefy, I've never seen a bad one. If you strip the caliper down just remove the seal and clean/scotchbrite the groove and put it back in, also check the piston is not pitted, you can buy/make stainless ones.

[eldar]

For the most part, I think the k2-k6 had the same style caliper and he 77-78 were a bit different. Now the F models for 77-78 wer quite a bit different. Get a pic if you can like Ben said OR look around on this site at some of the pics and then you can see what matches or at least get a good idea.

[Bob Wessner]

Also....the seals on the honda caliper are so beefy, I've never seen a bad one.

I would agree they are beefy, but after perhaps sitting in old contamintated fluid, or worse, no fluid for a period of time, not sure it matters. They are cheap. Actually, considering it's for a system that must work 100% of the time you need it, the cost of all parts for a brake system rebuild are cheap.

I'm no expert but.. I did sleep at a Holiday Inn Express last night. 

[alfabeast]

Bob..you're right, you shouldn't take it for granted that the seals are good, I guess they could dry rot or get torn up by a pitted or rusty seal.

[Nicholosi]

Well, mystery seems to be solved. Dennis Kirk sent mislabeled pads. Spec for part number VD-102 (vesrah) is 50mmX20mm. Even though the box said that's what they were, actual size was 52mmX20mm. I'm gonna order the correct ones and get a new seal while I'm at it, you guys convinced me. The piston looks good, so I think I'm allright there. I might post a couple pics just to get further reassurance.

thanks

[Nicholosi]

Photo is my caliper, bottom left new pads (wrong size), bottom right old pad (other one fell apart). Dimension on old pad is 50mmX19.19mm. I'm still not sure if I need vesrah part number VD-102 or VD-101. Both are 50mm but different thickness. I'm thinking VD-101 because it (according to drawing on vesrah website) has the stud to secure it to caliper on side opposite of piston (if that makes sense to anybody).

Anyway, have a look and advise the dumb guy.

Thanks.

[TwoTired]

Looks like a very early type to me.
I think the VD-101 should work.

[Bob Wessner]

A little hard from the pic, but without having it in hand to take to the garage and compare, it looks very much like the brake bits from my K0. If there are any remnants of black paint on either of the caliper halves, it could be from a slightly later model like K1, etc.

[Nicholosi]

Thanks, you guys got me squared away.