Blue Spot maintenance guide.

[fung]

The curse of the piston binding
Mr. Yamaha forgot to tell that the famous blue spot calipers require a specific maintenance : cleaning the pistons. The problem is that the pistons fit in their bores with very limited looseness. Then dust settle around the pistons and soon forms a hard deposit which seize the piston. As a Result, it is not uncommon to have only one piston to remain operational inside each caliper. This lowers the braking efficiency and generates an asymmetric pads wear - maybe other strange figures - and finally makes the brake lever less firm . This is difficult to realize because the phenomenon is very progressive.

The solution : remove the calipers, clean the pistons one at a time while pushing them partially out. Rub the piston with a soft rag, using some brake fluid if the dust layer is hard. There also exists so-called "special calipers cleaning" fluids, but since there does not exist standard for these cleaning fluids, so there's something for brake fluids (including compatibility with seals), I prefer to use only genuine brake fluid on any brake part.

• Remove the two mounting screws and the caliper .
• Push back the pistons with the old pads still in place

• Remove the beta clips, the pad pin and the pad spring .
• Remove the pads & take note of their locating (internal / external).

• Place a wedge (wood or hard plastic) to block a pair of piston.
- Operate the brake lever to push one of the remaining two pistons out , blocking the other with the hand .
• Don't push it out past the casting otherwise the piston may come fully out !
• Clean the piston using a small rag around, add some brake fluid if the dust layer is hard.
• Push the piston back and proceed with the others.

• Replace the pads, swap them if the wear is different between both.

• Replace the pad spring with the arrow-mark pointing forward, replace pad pin and beta clips .


• Install the caliper on the front fork, tighten the screws to 4.0 m.kg.
• Proceed with the other caliper.
• Operate the brake lever several time to push the pads in contact with the discs.

The result is really worth it : stiffer break lever, increased braking power, now it's time to change the front fork oil !

[Mincehead]

I have a blue, silver, gold spot `key` cnc`ed from aircraft grade alloy hex bar. The spots once removed allow full cleaning to easily take place.
They are not expensive but a damn useful tool :

http://www.ebay.co.uk/itm/Yamaha-Blue-S ... 19ce7828a4

[fung]

as i have never pulled them apart, whats to discover under the blue/gold/silver spots when you take them out?
do you require new rubbery bits to reassemble them?
cheers
fung

[Mincehead]

As far as I`m aware there are no O rings or gaskets as such, the `spot` removal just aids thorough cleaning etc.

http://www.oemmotorparts.com/oem5.asp?M=Yamaha&T=YZF R1 1000&Y=1998&L=YA-YZF-R1-1000-1&O=FRONT BRAKE CALIPER&F=YA-YZF-R1-1000-1_bk&L2=YA-YZF-R1-1000-1_bk

No O rings or gaskets shown on the parts listings fung but I`ve yet to do one myself.

[fung]

i did some digging around, and found that the blue/gold/silver/blackspot screws in thru the caliper and has an o-ring seal on each one.
theory is, blow the piston out then screw out the plug in and out the other side.
full stripdown this is
cheers
fung

[Mincehead]

Ahaaaa, well done that man

[Dav]

How far out can you push the pistons approx before they fall out? I need to do some brake maintenance and don't want a woopsie moment
Later on: I pushed em out about 7mm to be on the safe side. Thanks for the inspiration to do the job Fung. I also changed the brake fluid for what appeared to be the first time since the bike left the factory...disgustingly muddy semifluid Brakes now lovely...cheers

[dandywarhol]

This of course is called progress - think of the weight saving from not fitting dust seals...................