Rear brake pin

[Santa-2512]

As the bike is minus the rear diff,

I thought id take the oppertunity to look at the rear brake, i dont think its as good as it could be

trying to move the pads in the caliper, its evident that the pads are binding on the locating pin.

i popped the locating pin and pads out, and gave the pin a good clean, but noticed near the split pin end of the

alignment pin, there appears to be a groove about 4mm wide. is this normal?

 

[Andi_archer]

A picture would help ,is it to facilitate a flat screw driver head?

 

[Santa-2512]

No its actually cut into the circumferance of the pin

Almost like a notch

 

[milleplod]

There should be a tapered spring collar thing (collet?) in that groove (possibly to stop the pin rattling?). When I bought a stainless pin, it came without the collar, it was a pig to get it off the old pin! Yours must be missing! I can't find a decent pic unfortunately.

https://www.motorworks.co.uk/vlive/Shop/Parts.php?T=6&Q=BRA90537

Pete

 

[Santa-2512]

There should be a tapered spring collar thing (collet?) in that groove (possibly to stop the pin rattling?). When I bought a stainless pin, it came without the collar, it was a pig to get it off the old pin! Yours must be missing! I can't find a decent pic unfortunately.

https://www.motorworks.co.uk/vlive/Shop/Parts.php?T=6&Q=BRA90537

Pete

Almost ,

I have the spring collar, but if you look at the attached link the three grooves in the middle are all near the splitpin hole and as one

I'll try and grab a pic of the part when it stops raining

My suspicion is it shouldnt be there

 

[mikeyboy]

If I understand your description it may be where the pad has been wearing the shaft of the pin,
The pin should be parallel along its length
Or the split collar is missing

 

[milleplod]

Are we talking about the same thing I wonder? The 'collar' is at the very left end of the pin in the pic, and sits in one 'groove' around the pin. My stainless replacement doesn't have the 3 grooves that are nearer to the right end of it.

Pete

 

[Santa-2512]

If I understand your description it may be where the pad has been wearing the shaft of the pin,
The pin should be parallel along its length
Or the split collar is missing

Thats my suspicion, as i say i'll get a pic up tommorow to confirm

 

[OldCroc]

I think the grooves are pad wear indicators.

 

[Bendy toy]

The pad retaining pin should be smooth but wear ridges probably wont really affect how the brake operates. The pin on mine was quite obviously worn but the pads were free to move and the caliper was not binding anywhere. However, my master cylinder was corroded so the shuttle was not returning to rest. Fluid in the brake could not escape when pedal pressure was removed.

The old type master cylinder has a thin rubber boot that lets in dirt and looks non removable. Later models have a corrugated boot that can be taken off for cleaning. As you have the bike out of use, take the rear master cylinder off and check it for corrosion where the push rod connects.

 

[Santa-2512]

I think the grooves are pad wear indicators.

No,
Pads are Brembo Red, copper sintered

the wear groove on the pad is on the pad, this groove is on the retaining pin

 

[Santa-2512]

The pad retaining pin should be smooth but wear ridges probably wont really affect how the brake operates. The pin on mine was quite obviously worn but the pads were free to move and the caliper was not binding anywhere. However, my master cylinder was corroded so the shuttle was not returning to rest. Fluid in the brake could not escape when pedal pressure was removed.

The old type master cylinder has a thin rubber boot that lets in dirt and looks non removable. Later models have a corrugated boot that can be taken off for cleaning. As you have the bike out of use, take the rear master cylinder off and check it for corrosion where the push rod connects.

Ive never been happy with the operation of the back brake.

pads on one side seem more worn than the other, when i stamped on the pedal a few times, it freed things up a bit,

The pistons are free, and the outer pads move with the pistons.

the inner bar / retaing pin side didnt seem to want to move.

My suspicion is the inner pad has worn a groove in the retaining pin, this then prevents the pad from moving freely as it is sitting in this groove.

The other end is moving, but with limited travel.

Ill get out to the garage and get the pin photographed tommorow.

 

[Santa-2512]

If i strip the rubber boots( not pistons) and caliper slider pins, any reccomended greases i should use?

I normally use coppaslip on brakes, sliders etc. or do our tutonic friends reccomend somthing different?

 

[Littledumptruck]

Copperslips fine on metal to metal parts, but don't use it on anything rubber as the solvents in it make the rubber swell. Red rubber grease for anything rubber.

Has your pin still got the small loose bush on the end, or is that missing, hence the groove? (Left hand end in MW pic)

 

[milleplod]

Ive never been happy with the operation of the back brake.

pads on one side seem more worn than the other, when i stamped on the pedal a few times, it freed things up a bit,

The pistons are free, and the outer pads move with the pistons.

the inner bar / retaing pin side didnt seem to want to move.

My suspicion is the inner pad has worn a groove in the retaining pin, this then prevents the pad from moving freely as it is sitting in this groove.

The other end is moving, but with limited travel.

Ill get out to the garage and get the pin photographed tommorow.

I think rear pads are supplied with different thicknesses from new, to ensure they wear out at the same time - or at least genuine BMW ones are. Pretty sure my Ferodos were different too. Aren't the 3 machined grooves the wear indicators?

Pete

 

[Mistacat]

Ive never been happy with the operation of the back brake.

pads on one side seem more worn than the other, when i stamped on the pedal a few times, it freed things up a bit,

The pistons are free, and the outer pads move with the pistons.

the inner bar / retaing pin side didnt seem to want to move.

My suspicion is the inner pad has worn a groove in the retaining pin, this then prevents the pad from moving freely as it is sitting in this groove.

The other end is moving, but with limited travel.

Ill get out to the garage and get the pin photographed tommorow.

The inner pad always wears more than the outer.
If you purchase Lucas TRW pads the inner pad is 2mm thicker than the outer pad, so that they both wear out at the same time.

 

[milleplod]

Copperslips fine on metal to metal parts, but don't use it on anything rubber as the solvents in it make the rubber swell. Red rubber grease for anything rubber.

Has your pin still got the small loose bush on the end, or is that missing, hence the groove? (Left hand end in MW pic)

That's what I asked 10 posts back.

Pete

 

[Bendy toy]

If the captive ring has come off you are likely to have some serious problems its very well crimped on. TBH its not needed because the pi and has an R clip to keep it safe. If in doubt buy a new pin and pads into rattle clip kit.

 

[Kenny Rodkiss]

The correct lube, a little bit pricey but it's the right stuff for the job. http://www.ebay.co.uk/itm/BRAKE-GRE...G-ELSE-STOP-/253064197022?hash=item3aebcd339e

 

[Bendy toy]

While its off the bike take out the caliper pistons clean the seal grooves and seals. Put back with red grease. Takes 1/2 hour plus bleeding time.

I rub some copper antiseize into the retaining pin's captive washer (so it comes out easier next time) and put a fine smear on the opposite ends of the brake pads. That's all it needs.

Grease the slider pins with red rubber or ordinary grease.

Vibration will wear the retaining pin so replace when worn.