HOW TO: Replace Rear Brake Pads & Disc

[Coconut]

Edited 22/07/17 - To add Links for Images in new Forum Members Gallery.

Information :
Rear Disc minimum acceptable thickness = 4.5mm
NEW Disc ( 282mm Diameter ) thickness =  5.0mm,
Rear Disc maximum acceptable run-out = 0.225mm ( 0.125mm disc, 0.10mm bevel box )
Note for Service Manual owners : The above information for Disc Run-Out is correct,
as per Section 1.36 ( "Specifications" ) of the Service Manual. 
Section 15.28 ( "Brakes" ) of the Service Manual incorrectly states Max run-out to be 0.5mm ).
Minimum Brake Pad lining thickness = 1.5mm

Brake Fluid Specification : DOT 4 Brake & Clutch Fluid.

Triumph Part Numbers ( World of Triumph ) :
Rear Disc = T2025100
Rear Pad Set = T2025045
Disc Bolts = T2020608 - 5 required.
Pad Retaining Pin Set ( 2 Pins ) = T2020966

Disclaimer :
As with any advice and information I provide on this Forum,
which is provided "as is" with no guarantees or come back,
you should carefully consider your own skills and abilities
before undertaking any such task, and ask yourself,
"After spending all that cash on my Trophy, do I really want to save a few Pounds / Dollars
by attempting the work myself, rather than entrusting it to a Triumph Dealer - who has access
to all information necessary, and has the skills and knowledge to do the job properly ? !"

But if you do want do it yourself ........

Replacing the Rear Brake Pads :

Inspect Pads regularly in accordance with the Service Schedule.
If the centre of any pad has worn down to the bottom of the wear indicator groove,
then both Pads should be replaced with a new set.

1.  There is no need to remove the rear wheel.

2.  Slacken the two Brake Pad retaining pins.
The Pins can be quite tight - Use a good quality Allen key / Hex tool
to ensure the Pin is not damaged and the hexaganol hole rounded out ! 


3.  Undo and remove the two Brake Caliper retaining bolts.
Pack some cloths / towels around the area to protect the caliper, frame, wheel etc,
and place the caliper so that there is no strain on the flexible brake hose,
in a position to allow removal of the pad retaining pins.

4.  Before withdrawing the Pad retaining pins,
note how the pads are located in the caliper.
( Taking Photo's is a great idea for later reference ! ).

5.  Withdraw the pad retaining pins -
pushing down on the pads to relieve tension on them as they are withdrawn.

6.  Remove the pads noting the location of the Anti-rattle spring.
( Take another Photo ! )

7.  Clean and inspect everything, but do NOT use any Mineral or Copper based grease
anywhere that it may come into contact with any of the Braking system seals or dust seals.
Use a proprietary High Temperature Brake Grease on the tips of the Pads where they locate in the Caliper,
and a Red Rubber type Grease for the sliding pins.

8.  If re-using serviceable Pads, clean out the wear indicator groove before refitting.

9.  When fitting new Pads, PROVIDING the Brake Fluid has not been topped up previously,
use hand pressure to carefully push the pistons fully back into the caliper,
otherwise refer to the cautionary note in the Chapter below for Replacing the Brake Disc .

10.  Refit the Anti-Rattle spring to the caliper ( Check that Photo you took ! )

11.  Refit the Pads, or fit the new Pads ( Check that first Photo you took ! ).

12.  Lubricate the Pad retaining Pins with a Minimal quantity of
Red Rubber type grease. Refit the Pins but do not tighten at this stage.

13.  With the Pads correctly located in the Caliper,
place the Caliper back over the Disc and line up the mounting holes.

14.  Fit the 2 Caliper retaining bolts and tighten to 40NM

15.    Now you can tighten the Pad retaining pins to 18NM - MAXIMUM !

16.    Pump the Brake Pedal a few times to locate the Pads against the Disc.

17.    Check the level of Brake Fluid in the reservoir, and adjust if required.

18.    Test that the Brake operates correctly, and if new Pads and / or Discs
have been fitted, break them in carefully over the next 200 miles.


Replacing the Rear Brake Disc :

1.  The Service Manual says to remove the Silencer,
which is quite simple, just one bolt securing the silencer to the bracket,
and a bolt for the pinch clamp securing the silencer to the exhaust pipe.

The rear wheel "can" be removed by loosening the above bolts
and moving the silencer slightly to give enough clearance for the wheel to pass,
but this risks scratching the silencer,  and/or damaging the flutes of the Downpipe
where the Silencer locates, so it is best to remove the wheel and put it somewhere safely out of harms way !

2.  Remove the rear wheel - 5 x 15mm Hex Head bolts to undo.
Put the wheel out of the way ( Take the opportunity for a good inspection of the tyre )

NOTE - CAUTION : If the disc is badly worn and has a lip on the outer edge,
the pads / pistons may need to be pushed back into the caliper
to provide enough clearance for removal of the caliper - complete with pads.
Similarly, if a new disc is being fitted the pads may need to be pushed back,
as the new disc is likely to be slightly thicker than the one being replaced.
Take care doing this - I would recommend fitting a tube to the Caliper bleed nipple,
opening the nipple and then pushing the pads back by hand pressure or a suitable tool
( taking care not to push against the disc if it is not being replaced ),
and directing the expelled brake fluid via the tube into a jar.
This will reduce the possibility of brake fluid overflowing from the reservoir.
( Brake fluid is corrosive to paint work ! ).
Tighten the nipple after pushing the pads back
to ensure no air is drawn into the system.
If the Bleed nipple has opened at all, it is good practice
to bleed the system befofe riding, to ensure no air has been introduced.


3. Unless already removed to change Pads,
Undo the two caliper retaining bolts, then remove the caliper from the disc.
( The Pads can be left in the caliper if they are not being changed ).
Using a length of wire or similar, hang the caliper from part of the frame
so that the flexible hose is not strained by the weight of the caliper.
It's a good idea to wrap cloth around the caliper to prevent it scratching other parts.


4. Undo the 5 fixings securing the brake disc.
NOTE : When refitting the disc, or fitting a new one
Triumph recommend using 5 new fixing bolts.


5. Ensure the mating face is clean, align the new disc,
and fit the ( new ) securing bolts - tighten them to 22NM.

6. Position the caliper back over the disc, line up the mounting holes,
fit the two bolts and tighten them to 40NM.

7. Pump the brake pedal a few times to ensure
the Pads are seated onto the surface of the disc.

8. Refit the rear wheel - tighten the 5 bolts in the sequence shown to 70NM.


9. Refit or re-tighten the Silencer.
Silencer to mounting bracket = 35NM, Silencer to Exhaust pipe clamp = 10NM

10. Check the level of Brake Fluid in the reservoir and adjust if necessary.

11. Check that the brake operates correctly - new Pads and / or Discs
will not achieve maximum braking efficiency until they have “bedded in”.

The brakes should be used carefully over the next 200 miles. 

[Studley]

Thanks Coconut, could be facing this job soon. Appreciate all your work

Studley

[Troph-@-63-FR]

Félicitations Coconut 

[KaliforniaKook]

Great how to (as usual).

You didn't mention anything about front disc brakes. Is that because you consider self-evident? I couldn't find a counterpart to the retaining pin set for the front, but do you think the pad springs are necessary?

For some reason, my front brakes suddenly started pulsating. Dealer says warped rotors - replaceable for ~ $900. Parts from the site you cited are about 732. But I kind of like working on the bike.

[Coconut]

You didn't mention anything about front disc brakes.
Is that because you consider self-evident?

No, It's because the Topic is "HOW TO: Replace Rear Brake Pads & Disc ! 

I don't think there's a specific "HOW TO" for the Front Brakes, ( at the moment )
but if you'd like to start a new Topic discussing this,
I'm sure you'll get any answers you need about the front pad retaining pins.

There are also existing Topics about the front brakes pulsing, or front discs warping,
just use the Search Button and type in "Warped Discs" 

If you are referring to the Anti-Rattle springs for the rear brakes - Yes - I think they are necessary !

Cheers 

[McVicar]

Just looking at replacing my rear pads. Referred to this topic nearly 7 years after posting. Thanks as always Coconut. 

[LarryJa]

I'm in-process of replacing my rear pads & disc.
I've removed the muffler & rear wheel, & secured the disc in position by tying of the brake pedal with the brakes engaged.
I've  gone to remove the disc "fixing" bolts. However, these bolts are very tightly secured(& a bit rusted) in place after 10yrs & 70k miles.
I tried loosening the 1st one, & the T-30 torx head has begun to give a little,  but the bolt is solid in place. I stopped, hopefully, before causing a disastrous head strip. (But the socket IS a bit looser in it than before!)
My question is: do these bolts require heating, prior to disassemble, to loosen any "threadlok"  etc?
What is the experience with this disc removal?