Topic: Is this caliper piston usable?

[jorwesflow]

just released this from the caliper using the grease gun method...worked like a charm! but is it useless when it looks like this???

[splitt]

Yep, it's a goner. You can probably pick up a NOS caliper to get going. If you want something that'll last, there are some machined stainless steel calipers out there also, but be prepared for the sticker shock.

[scottly]

That's about the worst piston I've ever seen!!!! What bike is it from? There are inexpensive pistons available for some models.

[GammaFlat]

Did that thing spend some time in the ocean (salt water)?

[jorwesflow]

yeah the new pistons aren't cheap. where are there cheap replacements (aftermarket?)? this is from a 76 cb550f. it's been a headache since the day I picked it up last year. :/

[scottly]

Do a search for phenolic pistons; a fellow member modifies automobile pistons to fit your bike, at a very reasonable price. 

[johnrdupree]

Kevin400F supplies the phenolic pistons: http://forums.sohc4.net/index.php?action=profile;u=1440

Good product, fast delivery, 1/2 the price of OEM, and it will never rust.

[flybox1]

Kevin400F supplies the phenolic pistons: http://forums.sohc4.net/index.php?action=profile;u=1440

Good product, fast delivery, 1/2 the price of OEM, and it will never rust.

Ummm...yeah.  Looks like youve got yourself a new paperweight right there 
when it comes to things that make you STOP, take no chances!  when in doubt, i replace.
i've heard nothing but good things about kevin400f's phenolic pistons...

[TwoTired]

just released this from the caliper using the grease gun method...worked like a charm! but is it useless when it looks like this???

Yes, that is the worst I've ever seen.  Is the aluminum in the caliper in a similar state?  If so, I expect the previous rebuilder skipped the silicone grease coating, meant to protect those parts from corrosion.
If the caliper is as bad as that piston, it should probably be replaced as well.

Cheers,

[Kevin400F]

Yep, that's the worst brake piston I've ever seen as well.  How's this for the worst drive sprocket:

[ekpent]

I second the nomination for worst sprocket  Was that thing still kind of working and what did the rear look like??

[wrenchmuch]

Looks more like something a ninja would throw . Did the bike still move in a forward direction ?

[jorwesflow]

thoughts on the inside of the caliper?

if ya'll think its still usable, kevin400f, how do I get a hold of one your famous pistons?

otherwise, I'll find a whole new caliper.

[crazypj]

Caliper looks OK to me.
Needs a good cleaning but should be fine.
Get 'plastic' piston, I just did my CB360 with one and it's much better than stock (don't get any heat transfer through piston, only through caliper body)

[jorwesflow]

crazypj, this is actually after a moderately intense cleaning. I soaked it in carb cleaner overnight (good decision?) and then scrubbed with soap and water. what else should I do?

[seaweb11]

I would have to disagree with PJ on this. I would personally look for a replacement.
  I wouldn't use that on any of my bikes.

- I Found one here that might work for you.
 http://cgi.ebay.com/ebaymotors/1977-honda-cb550-cb-550-four-K-h244-front-brake-_W0QQcmdZViewItemQQhashZitem3a65c2870bQQitemZ250815350539QQptZMotorcyclesQ5fPartsQ5fAccessories#ht_711wt_941

[jorwesflow]

seawebb, thanks! I have been searching eBay for "cb550 caliper" and missed this listing. in my watch list now..

[seaweb11]

I like to know the important bits are up to snuff is all
 That ebay link would be easily worth $75.00+ right now to you.  You won't get many chances.........and you know you want to ride it

You could perhaps assume your lines are all crudded as well. Did the switch work?  hmmmmmmm

[ekpent]

Try dressing up the inside of the caliper with some fine #0000 steel wool and maybe some 400 wet dry in the area where the pad sits to rid it of the rusty film and crud and then see how it looks. Simple soak is not enough.Clean all the chud out of the inner ring well where the rubber seal goes also if you keep it.

[TwoTired]

For one thing, you have to get rid of all the orange and get to the bare aluminum.
Scotchbrite (NOT steel wool on aluminum) and/or 400 grit aluminum oxide paper.

If the seal grove still retains original contour the caliper will still work fine.  Use and inspection mirror to view the groove.  If pitted, a replacement caliper is indicated.

Cheers,

[jorwesflow]

Do the Calipers on the F's and K's differ? Looking on Bike Bandit, the '75 and '76 CB550F's are both identical calipers, but the K's seem to have different part numbers.

i was about to bid on a caliper for a '75 CB550 (F or K not specified), and i thought i'd better quadruple check that it fits my '76 CB550F. Judging by the pics, it looks like it should. But looking at the Part Numbers on Bike Bandit, I am doubting this purchase.

Does anyone have any insight into this?

[TwoTired]

I never noticed a difference for any of the CB550 Calipers.

[Kevin400F]

I looked on BikeBandit's goofy version of the microfiche, where they substitute their own part numbers.

Comparing the 1976 "F" and "K" parts listings, they have the same two BikeBandit part numbers for the inner and outer caliper halves (654839 and 654906), but they simply transpose the numbers between the two models.

Kevin