Topic: 72 cb500 4 Front brake caliper piston seal size issue

[23skidoo]

So i'm basically replacing my front brake piston seal, i ordered the proper honda part#45108-300-003
when i put the new seal in, the damn seal is too small. compared to the old seal the new ring is clearly alot smaller.
Does anyone know if this is correct, is there a trick to forcing this seal to work? the old seal measures
about 42.88 mm , not sure where to go from here, any info would help thanks.

[dave500]

is it the correct part in a sealed bag?a honda one?does it go anywhere close to fitting?i have a genuine new one if you want me to measure it,,maybe you were supplied the wrong one?

[23skidoo]

hi thanks dave, it was ordered from my trusty honda dealer, it came in your regular sealed plastic honda package with the correct part# on it. The new piston seal measures 1 and 13/16 inches, sorry i have my mm measuring tool at my garage. Researching the part it seems it fits most and many 70s cb's, when i put the seal in place its off by enough that it wont pop into place if i force the brake piston in.

[dave500]

wrong part in the bag?you should measure any jap stuff in metric anyway,get used to it,ok,,heres a photo,i make it 44mm outside,about 38 internal,its a square profile seal you have?

[23skidoo]

Thank for posting the pic dave!, thats the exact size i have 44 mm and 38 on the inside, i'm starting to think
the mofo who owned my bike before me replaced the brake caliper with another model bike,
it's the only thing i can figure. so either now shooting in the dark or just buy the proper brake caliper
and replace the whole thing.