How to: Replacing rear brake seals and fluid

[Nelly]

Today I replaced the rear seals and brake fluid.
Loosen the two bolts that secure the caliper. Remove outer screw (PIN PLUG) that protects brake pad pin and loosen brake pad pin.
Remove rear wheel and remove calliper.

Remove brake pad pin and pads. Don't get grease on braking surfaces.

Pump rear brake to push out piston (you can also use compressed air).

Do it over a container and be careful not to splash painted surfaces as once the piston is out the fluid will drain out.

Clean with a new cloth and brake fluid. Put piston in a safe place do
not drop or damage piston.
Clean calliper surfaces with clean cloth and brake fluid.

There are two seals inside the caliper. I removed them with a
small engineers screwdriver.

Clean the seat for the seal with brake fluid and clean cloth.

Lightly grease the outer edge of the seal with brake grease.

Press the seal into seat with a finger using a circular motion.
Do this with both seals.

Lightly grease lower part of piston and push into caliper.
(warning do not replace piston wrong way round as I first did). Install closed end first.

CORRECT FITTING

This helps seat the seals and disperse the grease lightly onto piston surface.

Reinstall pads, making sure that they sit correctly in the pad plate

Clean and grease pad pin and insert pad pin.

Clean and grease calliper retaining bolts check the rubber boots for cracks. Remove calliper slde and clean and grease.

Give slide a good wiggle to work in the grease.

mount caliper and tighten.

Make sure pads are seated correctly.

Raise petrol tank and unscrew
top off master cylinder on right side of frame . (You can access master cylinder without raising the tank but its tight).
My fluid was very dirty looking (at this stage of the build the master
cylinder will be empty after draining the fluid when the piston was removed)..

Top up brake fluid with dot 4 fluid.

Unscrew bleed screw on caliper with 8mm spanner 1/2 a turn.

Connect a length of tubing to bleed screw and run it up vertically.

I used the grab rail to secure it.

Now pump the rear brake,
this takes about 2 minutes depending on rear brake pedal travel. Keep an eye on the
master cylinder fluid level as
you need to expel all the air
from the line without introducing
more air into the system.

It takes about 30 MLS of dot 4 fluid to prime the master cylinder
and line from empty.
I also put the cap back on to
reduce the risk of debris falling
into the new fluid. Pump rear
brake until you feel the leaver
start to stiffen and and the fluid level will drop with each press of the rear brake leaver.
The new fluid will start to run up the tubing connected to the bleed
screw.

You will see bubbles of expelled air in the fluid. Give the rear leaver
enough presses to expel all air bubbles.

Once this is done top up fluid level. Screw cap back on.
Next keep rear brake leaver depressed and tighten bleed screw with 8mm spanner.
Once completed release brake and give the rear wheel a good spin,
and check to see that the brake bites and stops wheel.
Pinch bottom of tubing on top of bleed screw and remove tubing.
Replace bleed screw dust cap.
Do not spill any fluid on painted surfaces.
Check all nuts and bolts are tightened to specification and job done.

Torque settings
Brake calliper bleed screw 6 Nm.
Rear brake calliper mounting bolt 22Nm.
Rear brake calliper slider pin 27Nm.
Rear brake pad retainer pin 17Nm.
Rear brake pad retainer pin plug 3Nm.

A big thank you goes out to UK member, Greg for his help and advice on how to do this work.
Also a big thanks to my forum friends for help and advice on piston install.
New pads will take a while to bed in just like new tyres.

Happy riding

Neil

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[wolfe1down]

Great write up and how-to. Thanks! Will be doing this in the off season (any time now)

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[FB400]

Re: Replacing rear brake seals and fluid

+1 on doing a great write up. Nice work!!

I never saw that method of bleeding brakes before. I will have to try it next time

 

[Hellgate]

Thanks man. I need to rebuild my calipers and this is the perfect primer.

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[Nelly]

Re: Replacing rear brake seals and fluid

Thanks man. I need to rebuild my calipers and this is the perfect primer.

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High praise indeed,
cheers

neil

 

[shamrocker]

Re: Replacing rear brake seals and fluid

Thanks for the write up. Do you happen to have a link to purchase the seals?

 

[greg]

Re: Replacing rear brake seals and fluid

You haven't put your piston in the wrong way around have you? The hollow bit should be on the outside.

 

[TownsendsFJR1300]

Great write up Neil!

One small problem and something to add:

The piston shoud be in the caliper with the hollow part sticking outwards(visable), NOT INWARDS... The flat part of the piston should be inserted first..
Someone may have had it apart previously, the fronts of my FJR (original owner) and FZ (I was the first one to pull the ft calipers apart and rebuild) ALL had the front wheel pistons with the flat in first...

Second recommendation, make sure the floating pins/bolts are pulled out and the old grease removed/cleaned... Make sure the rubber boots are not torn/worn, etc. It tends to gum up over time / stick and thus not float... Fresh brake grease helps the assembly slide and center itself as the brake pads wear...

:thumbup:

 

[FinalImpact]

Great write up Neil!

One small problem and something to add:

The piston shoud be in the caliper with the hollow part sticking outwards(visable), NOT INWARDS... The flat part of the piston should be inserted first..
Someone may have had it apart previously, the fronts of my FJR (original owner) and FZ (I was the first one to pull the ft calipers apart and rebuild) ALL had the front wheel pistons with the flat in first...

Second recommendation, make sure the floating pins/bolts are pulled out and the old grease removed/cleaned... Make sure the rubber boots are not torn/worn, etc. It tends to gum up over time / stick and thus not float... Fresh brake grease helps the assembly slide and center itself as the brake pads wear...

:thumbup:

Also, This is just me, but I use a turkey baster and suck out the old FLUID FIRST! Clean out the reservoir and fill it with new fluid. Bleed the brake until the new fluid comes out clean.
-> Now remove the caliper. What you gain here is sediment from the reservoir does not go right into the caliper and sit there wearing on the seals and breaking down.
During rebuild any pits, scratches, damage to the outer piston surface will destroy the new seals. Inspect it closely before re-using it.

All comments are correct; piston needs turned around and that slide really needs pulled apart and cleaned, greased to make sure it doesn't stick.

Do know that we appreciate the effort! Thanks man!

 

[Nelly]

Thanks guys, I never knew the piston was the wrong way in. I will rectify it tomorrow.
I changed the rubber boots last month and since the hanger issue regularly re-grease the floating caliper bolts.

Neil

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[Nelly]

Today I replaced the rear seals and brake fluid.

Loosen the two bolts that secure the caliper. Remove outer screw (PIN PLUG)
that protects brake pad pin, and loosen brake pad pin.
un-screw the two calliper retaining bolts to remove calliper.

Remove brake pad pin and pads. Don't get grease on braking surfaces.

Pump rear brake to push out piston (you can also use compressed air).
Do it over a container and be careful not to splash painted surfaces
as once the piston is out the fluid will drain out.

Clean with a new cloth and brake fluid. Put piston in a safe place do
not drop or damage piston.
Clean calliper surfaces with clean cloth and brake fluid.

There are two seals inside the caliper. I removed them with a
small engineers screwdriver.

Clean the seat for the seal with brake fluid and clean cloth.

Lightly grease the outer edge of the seal with brake grease.

Press the seal into seat with a finger using a circular motion.
Do this with both seals.

Lightly grease lower part of piston and push into caliper.
warning do not replace piston back to front as I first did
This helps seat the seals and disperse the grease lightly
onto piston surface.


Reinstall pads, grease pad pin and insert pad pin.

Reinstall rear wheel and brake hanger. Clean and grease caliper
retaining bolts check the rubber boots for cracks.
picture
mount caliper and tighten.

Make sure pads are seated correctly.
picture
Raise petrol tank and unscrew
top off master cylinder on right side of frame .
My fluid was very dirty looking (at this stage of the build the master
cylinder will be empty after draining the fluid when the piston was
removed)..

Top up brake fluid with dot 4 fluid.

Unscrew bleed screw on caliper with 8mm spanner 1.5 turns.

Connect a length of tubing to bleed screw and run it up vertically.

I used the grab rail to secure it.

Now pump the rear brake, this takes about 2 minutes depending on rear brake pedal travel. Keep an eye on the master cylinder fluid level
as you need to expel all the air from the line without introducing
more
air into the system.

It takes about 30 MLS of dot 4 fluid to prime the master cylinder
and line from empty.
I also put the cap back on to reduce the risk of debris falling into
the new fluid. Eventually you will feel the leaver start to stiffen and
the fluid level will drop with each press of the rear brake leaver.
The new fluid will start to run up the tubing connected to the bleed
screw.

You will see bubbles of expelled air in the fluid. Give the rear leaver
enough presses to expel all air bubbles.

Once this is done top up fluid level. Screw cap back on.
Next keep rear brake leaver depressed and tighten bleed screw with
8mm spanner.
Once completed release brake and give the rear wheel a good spin,
and check to see that the brake bites and stops wheel.
Pinch bottom of tubing on top of bleed screw and remove tubing,
replace bleed screw dust cap.
Do not spill any fluid on painted surfaces.
Check all nuts and bolts are tightened to specification and job done.

Torque settings
Brake calliper bleed screw 6 Nm
Rear brake calliper mounting bolt 22Nm
Rear brake calliper slider pin 27Nm
Rear brake pad retainer pin 17Nm
Rear brake pad retainer pin plug 3Nm

A big thank you goes out to UK member, Greg for his help and advice
on how to do this work.
New pads will take a while to bed in just like new tyres.

Happy riding

Neil

Sent from my HTC Desire S using Tapatalk 2

 

[pookamatic]

What's the life expectancy of the seals?

 

[Cloggy]

Many thanks for the (revised) write up Neil :thumbup:

Unfortunately I paid the stealer to do this for me (last week) along with some other work) and it cost me a fair packet, never again.
Next time I'll be following this how to :thumbup:

 

[greg]

Many thanks for the (revised) write up Neil :thumbup:

Unfortunately I paid the stealer to do this for me (last week) along with some other work) and it cost me a fair packet, never again.
Next time I'll be following this how to :thumbup:

it's really easy, only tricky bit is bleeding it properly

 

[Nelly]

Many thanks for the (revised) write up Neil :thumbup:

Unfortunately I paid the stealer to do this for me (last week) along with some other work) and it cost me a fair packet, never again.
Next time I'll be following this how to :thumbup:

I finally got there with the help of my friends lol.
It is very straight forward to do and hopefully it will set me up to do the front in the spring.

Neil

 

[TownsendsFJR1300]

What's the life expectancy of the seals?

Yamaha recommends seal replacement every TWO years. I've found the rear goes considerably longer time wise. The fronts (with the 4 piston pots) start dragging, give or take, 4 years or so..

 

[LERecords]

WOW thanks Nelly!! this is on my list for next year. Might just tackle it myself now!!!

 

[Nelly]

There is a recent thread with the link in it. Posted by Greg (UK member) that has part nobrted

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[Nelly]

So I have bleed the brake three times and feel very confident that the air is out. After riding the bike there isn't the usual bite I get when depressing the rear pedal.
New disk and new pads need to bed in. I also adjusted the travel of the rear pedal. Very easy to do. 12mm spanner to undo locking nut.

10mm spanner to adjust travel anti clockwise moves brake pedal up.
Clockwise lowers the pedal.

I will keep the thread updated with regard to the bedding period.
And of course any help or advice will be greatly appreciated.
Neil
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[TownsendsFJR1300]

So I have bleed the brake three times and feel very confident that the air is out. After riding the bike there isn't the usual bite I get when depressing the rear pedal.
New disk and new pads need to bed in. I also adjusted the travel of the rear pedal. Very easy to do. 12mm spanner to undo locking nut.

10mm spanner to adjust travel anti clockwise moves brake pedal up.
Clockwise lowers the pedal.

I will keep the thread updated with regard to the bedding period.
And of course any help or advice will be greatly appreciated.
Neil
Sent from my HTC Desire S using Tapatalk 2

Just a reminder, check your rear brake light adjuster switch, especially when adjusting the lever. You don't want it illuminated all the time or not coming on when it should. There's a plastic nut tucked in on the switch (kind of a PIA to get to) to adjust the switch..

If the bedding in doesn't get any better, I have/used a Mity Vac (don't know if its available down below) when I replaced my rear line with SS braided.

If not, you might have some some air where the brake line rises from the caliper . A fix for getting it out, pull off the caliper, block the piston so it can't COME OUT, hold the caliper higher than the master cylinder, so the air rises to the caliper and can be sucked out or pump/bleed (normal, no fancy tools bleeding). That's the only place air can be left, between the caliper and the rear brake pump..