Help on Rebuilding Calipers and finding the Yamaha Star shaped socket for the caliper

[Tom24GR]

Hello everyone,

After taking my calipers off the 2007 FZ6 I recently purchased I realized that 2 out of 4 pistons on each of my two front calipers are seized. Since the bike has 24,000 miles and I found a good caliper rebuild kit for a good price I would like to rebuild it (with new pistons and all brake pad hardware included).

My question is whether I will need the star shaped Yamaha caliper socket to do this job. Alternatively does anyone know what size it is and whether or not a large enough torx socket will do that job.

Does this tool make it possible for the piston to come out of the back of the caliper rather than through where the pads sit? I was under the impression that I could just take the pads out and keep pumping the brakes until the pistons came out of their seal.

Thanks in advance.

 

[Gary in NJ]

Usually star-type screws are Torq fasteners. I just went out and looked at my bike and don't see any Torq fasteners on the calipers. I checked the exploded views on-line and didn't see any torq's either.

The brake pad pin on the S1 may be a hex head (it's shown both as a cap bolt and shoulder bolt) - maybe someone swapped out what they had with what was there.

Got a photo?

 

[Tom24GR]

Those are the calipers I have on my bike. Each caliper has 4 pistons. The one I have are mounted differently but the star shaped thing is the same. The socket is described as "Caliper piston removal tool"

 

[Gary in NJ]

Sorry, I forgot. Since you don't have FZ6 forks, you also don't have FZ6 brakes.

You need this tool

Yamaha Blue Spot Caliper Tool Brake Piston Removal 7221000 For Yamaha Fjr 1300 | eBay

Find many great new & used options and get the best deals for Yamaha Blue Spot Caliper Tool Brake Piston Removal 7221000 For Yamaha Fjr 1300 at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[Tom24GR]

So that is 100% necessary right? In other words I can't just squeeze the pistons out using pressure from the fluid?

 

[Gary in NJ]

I don't think it is. Motion Pro makes a tool to extract pistons.

Brake Caliper Piston Tool - Motion Pro

Motion Pro - High quality cables, tools and controls for motorcycles, ATVs, snowmobiles and personal watercraft.

www.motionpro.com

You can use air pressure, but here's the problem; in order to get the long pistons out (the ones that use the star) you need to get the short pistons out first. You may be able to hold back the long pistons with an old brake bad and a bolt (to jam it in position). Once the short ones are out you can get the large ones.

But with the Motion Pro tool, you just tighten the tool into the back of the piston, and then give it a twist as you pull out the piston.

 

[Tom24GR]

Sounds good I'd rather give the motion pro a try because the other tool is going to take 30 years to get here form the uk

 

[TownsendsFJR1300]

I've never had to use that large shaped tool (and frankly, didn't know it existed). No where that I know of does Yamaha want you pulling those out. I personally wouldn't touch em. Here's the parts diagram below for the FZ. They don't them coming apart. Even thou their not original FZ6 calipers, the design is the same, same for the FJR too..

Now, for the sticky pistons. Couple ways to remove.

-Hydraulic , as noted keep the lines hooked up, get the Non-stuck pistons pushed partially out, then cut a piece of wood to sit in-between them to stop them from coming out fully.

-Now all your hydraulic fluid/pressure will be applied to the stuck piston(s).

-Last time I did my S2, I had a couple pistons sticky and used compressed air where the fluid would pass thru (about 100 PSI) as I re-call from the piston (fluid side/cylinder) orifice.

***DO NOT GET YOUR FINGERS anywhere those pistons as when they release, they will and with mucho force..... And wear eye protection as brake fluid will also be sprayed about when they pop loose.

Yamaha, for the seals included (for my S2 at least) some brake grease(no instructions and nothing in the manual about grease). Only use brake fluid on the seals pistons as indicated in the shop manual (see below):

 

[TownsendsFJR1300]

Just as an FYI, when the seals get old, they harden up and drag.

Mine after the new seals installed:

https://flic.kr/p/24gHvHC

 

[Tom24GR]

I tried this the other day before I took the wheel off and it spun around about 6 times as well. Although I think it needs a rebuild because, besides the one caliper that drags far behind the others, the pad wear is uneven.

 

[trepetti]

To remove the pistons easily, I purchased this..... https://www.motionpro.com/product/08-0591
Lay it across the piston, use the allen key to expand the tool to clamp the inside of the piston, then grab the tool with pliers and wiggle the piston out. Compressor works, but once 1 piston comes out you cannot use the compressor for the rest.

When I installed the R6 forks, I bought 2 really old 4 piston calipers. This tool made the rebuilds simple.

 

[Tom24GR]

im gunna go that route for sure

 

[trepetti]

im gunna go that route for sure

We Bronx-ites need to stick together I was born there....

 

[gnyce]

For really really stuck pistons (e.g. a bike 30+ years old).... a grease gun, marine grease, and the right fitting (on the brake bleeder) to attach. It's bizarre, but it totally works. I've used a compressor too, but it's a big more dangerous and won't get the really corroded ones. Having said that, Motion Pro tool looks a bit easier.

 

[gnyce]

Compressor works, but once 1 piston comes out you cannot use the compressor for the rest.

Respectfully beg to differ on this, but it certainly becomes harder. I've pulled 1 piston, take the seals out and cleaned up the piston, put it back in and clamped it (C-clamps, wood shims and paint stir sticks.... you get the idea) to keep pressure in for the remaining pistons. Not recommended or easy, but it _can_ work. Now, should you?? Likely not

 

[bigborer]

I've used anything from grease guns to using the hydraulic pressure from the maser cylinder to using compressed air... until I found a way of removing caliper pistons easily, with no damage and with no special tools. Also works GREAT for stuck pistons.
Sounds like a teleshopping add but it's not.

So:
-take any socket that's about ~90% the diameter of the ID of the piston; the shorter the better. Most times I use 1/4" and 3/8" sockets depending on piston size.
-take any 90 degree bent nose pliers that will expand the needles when pressed, the length from the bending point to the tip should be around the same as the depth of the piston
-put the socket inside the piston
-wedge the pliers needles between the socket and the inside of the piston. The pliers should slide in without resistance This will allow for a lot of leverage.
-twist and pull

Even the most stuck pistons should not take more than 2 minutes/piston to remove. If hand strength is an issue, you can always put the caliper inside a vise (or is the spelling vice?) and use both hands.

 

[Gary in NJ]

Vise

Motorcycles are a vice.

 

[trepetti]

Respectfully beg to differ on this, but it certainly becomes harder. I've pulled 1 piston, take the seals out and cleaned up the piston, put it back in and clamped it (C-clamps, wood shims and paint stir sticks.... you get the idea) to keep pressure in for the remaining pistons. Not recommended or easy, but it _can_ work. Now, should you?? Likely not

You are correct. I guess I was leaning mire towards the ease of using a compressor. Or a grease gun for that matter. It is more difficult to use those methods, especially on 4 piston calipers. Mayme its me, but I would rather strip it, clean it and then rebuild it, rather than 1 piston at a time.

I did my old 2 piston calipers with compressed air and it was ok. When I got the 4 pistons, I bought the tool and never looked back.

 

[Tom24GR]

Thanks everyone for your help! I'm currently finishing up my forks and then swingarm service and brakes will be next after that!

@trepetti No way!! Where at??

 

[gnyce]

I've used anything from grease guns to using the hydraulic pressure from the maser cylinder to using compressed air... until I found a way of removing caliper pistons easily, with no damage and with no special tools. Also works GREAT for stuck pistons.
Sounds like a teleshopping add but it's not.

So:
-take any socket that's about ~90% the diameter of the ID of the piston; the shorter the better. Most times I use 1/4" and 3/8" sockets depending on piston size.
-take any 90 degree bent nose pliers that will expand the needles when pressed, the length from the bending point to the tip should be around the same as the depth of the piston
-put the socket inside the piston
-wedge the pliers needles between the socket and the inside of the piston. The pliers should slide in without resistance This will allow for a lot of leverage.
-twist and pull

Even the most stuck pistons should not take more than 2 minutes/piston to remove. If hand strength is an issue, you can always put the caliper inside a vise (or is the spelling vice?) and use both hands.

If I don't buy the motion pro tool, am totally trying this next time. The downside of the grease gun method, while sure-fire, is the aftermath cleanup in all the nooks n crannies.