Topic: 1976 CB750F Front brake caliper piston

[spitfire]

Hi guys,
          As the front brake piston for the 76 CB750F (and presumably later K's) seem to be unobtainable (none at CMS or DSS) does anyone have any leads or experience with pattern ones ?

Cheers

Den

[bryanj]

If you have the part number try www.westernhillshonda.net and also what are the dimensions?

[starion88esir]

I too would like to know. I'd rather drop the money now while the bike is apart and replace it vs using old. and earing it down again.

[spitfire]

Hi Bryan,
              The part number is 45107-392-003, have found a place who say they have one in the US, JT Motosports, but I have been down this route before when ordering from the US, ordered OK, order confirmation E mail, then another E mail saying either they do not have the part or they don't ship outside the US, we will see. Have found a place in the UK that lists pistons by size rather than make so may have to measure mine and go down that route. http://www.toolparts.co.uk/acatalog/Complete_Brake_Calipers___Piston_and_Seals_Kits.html
Also found some stainless pistons on the US eBay so have some alternatives, may try Western Hills if this does not work out.

Cheers

Den

[bryanj]

Tried western hills and no stock, but it fits a 75/76 F; 76/77/78 A (not a lot of help to us in UK) and a 77/78K (Must be the K7 model).

I know you say DS has no stock but have you actually rung them as it might have a superceeded number? Other wise its a have one made I'm affraid

[bryanj]

That link looks good and the prices aint too bad either, dont worry if it sez dust seal is a boot, I am running a pattern wing piston on the 500 cos it was cheap and as long as its not new extra thick pads its no problem

[spitfire]

Yeah just got an E mail from JT Motosport, they are not currently shipping overseas, gosh what a surprise ! Like you I also checked Western Hills and they don't have any stock. So off to the garage to measure up and see if I can get one from the UK website.

Cheers

Den

[spitfire]

OK, just ordered one from Speedstyle Motorcycle parts will see what it looks like, for those of you with the same problem the piston is 42.97mm (Diameter) by 34.08mm long on my trusty digital caliper, they have a piston 43 mm by 34 mm which looks good enough to me.

Cheers

Den

[starion88esir]

Please, update me when it comes in. Mind if I ask how much it cost?

[spitfire]

No problem, the piston was £25 plus postage, which is $49.

Cheers

Den

[spitfire]

OK the piston arrived today, dimensionally it looks fine, 42.8 mm by 33.7 mm, the insert feels like alloy, I'll probably go with a Honda seal though.
Any thoughts anyone ?

Cheers

Den

[spitfire]

As Bryan stated the CB750F brake piston (45107-392-003) is the same piston fitted in the CB750A, K7 and K8, maybe others I only did a cross reference on the CB750.

Cheers

Den

[Bodi]

The "tour ace" one looks fine. There's no magic in the piston after all. Using a Honda seal sounds good, it has to fit the groove in the stock cylinder properly. If you have the white plastic donut I would skip using it with the new piston, and caot the inside of the piston with some silicon brake grease to reduce corrosion in there. That might dampen any potential vibration/squealing from the insert against the piston as well.

[pddpimp]

What bike was the piston you ordered for?

Do you have the part number for it?

Thanks much!!

[spitfire]

See above.

Cheers

Den