Stuck Front Brake Caliper Piston!! HELP

[randy]

Opflash,

Speed and Sport shows two "Piston Kits" in stock, which includes new piston, piston seal and dust boot, but check with them to be sure they have them.

4W1-W0057-00-00 PISTON ASY,CALIPER IT465 H, J 4W1 2 $47.18

Speed and Sport

[OpFlash]

cleaners that will not ruin the only seals that i have

hey there looks like ill have to try and keep the seals that i have for the time being. whats the best cleaner to remove that grease without damaging the rubber?

thanks guys

[randy]

How about brake fliud? It removes most anything. And it sure won't hurt the seals!

[prometheus578]

For cleaning the hardened gunk offa the caliper O-ring, I recommend brake fluid and a fingernail. Though I've never experienced it, but will pass it along, I've been told some brake cleaners, etc will swell the o ring causing probs when installing. was told that the NON clorinated stuff doesn't do that, but then again, this is just what I've been told.

[OpFlash]

thanks for the tip gonna try the brake fluid first. by the way any body have some extra seals for the xj or know where i can buy some? thanks only have seen em for the xs

[John]

One way to check on the compatibility of xs kits in an xj caliper would be to accurately mease the diameter of your piston, and then see if somebody else here would measure an xs piston, and see if they are the same dimensions. You may want to go to Yamaha's online parts catalog and start looking at the calipers for some of the other xj models. They may have the same calipers and the kits may still be available for them.

[John]

I just checked at Yama's site, and found the first three digits of the P/N are 4W1. That tells me that the caliper is used on another model, because if it was used only on the xj11 it would have a P/N beginning with 10M. I did a little research on the 4W1 p/n but coudn't find the origin. My some of the sharper knives in this drawer (TC) can help with locating the source application for the caliper.

[TopCatGr58]

Hey John and Opflash,

Well, I'm only a butterknife amongst chef's knives, but I had recently posted this reply about finding XJ caliper rebuild kits:

Yamaha changed the design of the pads and calipers for the XJ vs. the XS Specials, but apparently kept the same pistons and dimensions, cause on Partsnmore, the kit for the XJ front, is the same as for the Special front calipers. PNM are currently OUT OF STOCK of those kits, but you may find them elsewhere, just order for 79-81Specials Front! The Part # is 29-0128. Same numbers are used on OldBikeBarn. They state this kit fits many models, the XJ650, 750, XV920, and checking the parts fiche, they show the same root number for the piston assembly.

XV920: 2G2-W0057-00-00 PISTON ASS'Y, CALIPER
82XJ1100: 4W1-W0057-00-00 PISTON ASS'Y, CALIPER
82XJ650: 2G2-W0057-00-00 PISTON ASS'Y, CALIPER

So, I'm pretty sure it'll take the same kit! Just don't order one for the Standards, they ARE different designed calipers!
T.C.

[John]

Hey TC. I have found that the root number will remain the same for a particular part, but the prefix will change only when the par is changed. . For example...I bought some NOS fork springs for my SG. The new ones had a 2H7 P/N, but the SG had a 3J6 P/N, and the 2H7's were 4 inches too short. That is where the prefix comes in. It will tell yo the original application for that item. Like the ignitin module...the 2H7 was introduced in 78 and it never changed until the intro of the 4R0 in 81. Even though the part may be used on other models, it will retain it's original p/n until it is changed or modified. Another example is crank bearings... the rod bearings for our bikes are sourced from the xs750, and if you'll check, the bearings retian the 750 prefix, and the mains for an xs11 are used on an FJ11. I hav checked this on yamas site, and the mains had a 2H7 p/n, so seeing as how I had a complete set of main bearings, I re-bearinged SWMBO's FJ mains.

[Lamric]

Hi TC,

I wrote this based on the Yamaha parts manual explanation:

For Part Numbers in the format XXX-XXXXX-XX-XX

XXX-XXXXX-XX-XX The first three digits are the Model Code (every model in the Yamaha Product Line has a unique model number) all parts are given a Model Code of the first model they were used on.

XXX-XXXXX-XX-XX The middle five digits are the Basic Code number and indicate the section of the bike that the parts belong to (so 111XX means Engine, Cylinder Head).

XXX-XXXXX-XX-XX The next two digits are the Design Code and Design Change digits (so 01 means the part has had one design change).

XXX-XXXXX-XX-XX The last two digits are the Color Code and Size Code.

So, if the middle five digits are the same it just means they are from the same area of a bike, it doesn't mean the parts will interchange (although they might ).

Also, if anyone's interested in the Model Codes (first bike the part was used on) I've got a list of pretty much every one of them for the XS11s, it's a bit big to post here though.

[xj11john]

oh great!

I did the grease gun trick, and just sprayed out where the line fitting and bleeder area, I suppose now sitting in the hot sun all that grease is baked in!? I had to get a new front brake line for that reason, since i didnt have the bango bolt plugged up good enough, darn the luck!

[xj11john]

update on caliper

it was fine just pumped out the piston with the rear brake M/C and cleaned it out, reassembled and its fine.

[xs650mike]

I like the brake fluid as a cleaner idea. Whatever you use don't use any oily solvents such as kerosene, naptha (paint thinner) or the like and if you do clean everything well afterwards with MEK or hot lacquer thinner (ie. nitrocell thinner) so as to remove any residue. Oil and brake fluid do not go well together and will gum up. Don't ask me how I know.