Rear brake bleed question

[Dales venture]

Hi guys,

Going to bleeding rear brake on 92 VR shortly. I have the service manual and know the sequence to bleed (front right on it's own/ front left linked/rear brake and then proportioning valve). On the rear brake, the book says to undo caliper bolt and whilst caliper is still connected to front locating pin. rotate up 1.5 inches away from the disc and bleed as normal.

My question is that if the brake pads are away from the disc, the pistons will be forced too far out and might be difficult to force back in?

Is this correct as it is different to the way I've bled brakes on my other bikes. The others have all been bled whilst the pads have been in contact with the disc.

Advise would be gratefully received from an English cousin.

Thanks.

Blake

[SpencerPJ]

I've never bled the way the manual says to on my 83 (never read into it tho) ?? I'm like you, bleed it as sits on the bike. If you were to take it off and rotate it up 1.5 inches, I would slide a shim in between the pads. If it compresses too much, the piston is rather simple to compress with a 'c' clamp, even a large pair of channel lock pliers. Seems I started with the proportioning valve, front, than rear.

[BlueSky]

If there is no air in the system and you are just bleeding the lines to refresh the fluid, does it really matter how you do it if you are bleeding from the farthest point from the MC?

[Marcarl]

  BlueSky said:

If there is no air in the system and you are just bleeding the lines to refresh the fluid, does it really matter how you do it if you are bleeding from the farthest point from the MC?

 

Nope, don't matter, don't even really matter which you do first and you really wouldn't have to worry over the valves either....JMHO

[Marcarl]

  Dales venture said:

Hi guys,

Going to bleeding rear brake on 92 VR shortly. I have the service manual and know the sequence to bleed (front right on it's own/ front left linked/rear brake and then proportioning valve). On the rear brake, the book says to undo caliper bolt and whilst caliper is still connected to front locating pin. rotate up 1.5 inches away from the disc and bleed as normal.

My question is that if the brake pads are away from the disc, the pistons will be forced too far out and might be difficult to force back in?

Is this correct as it is different to the way I've bled brakes on my other bikes. The others have all been bled whilst the pads have been in contact with the disc.

Advise would be gratefully received from an English cousin.

Thanks.

Blake

 

The only reason to rotate the caliper would be to get the bleeder port to a higher position, so to easier bleed out the air. Pads would be left in place and should nicely slide back to working position. You won't be putting much pressure on them if any during the bleeding process.

[Dales venture]

Thanks for the advice.

[saddlebum]

  BlueSky said:

If there is no air in the system and you are just bleeding the lines to refresh the fluid, does it really matter how you do it if you are bleeding from the farthest point from the MC?

I would still bleed as thought there is air in the system. As brake fluid ages it absorbs moisture, this reduces its wet boiling point. When brake fluid reaches or exceeds its boiling point it devolps gas bubbles that act similar to air bubbles and so you want to bleed these out when replacing fluid.

 

  Marcarl said:

Nope, don't matter, don't even really matter which you do first and you really wouldn't have to worry over the valves either....JMHO

On the contrary the rule of thumb when bleeding any hydraulic system is to bleed the the furthest point from the master first and work your way back.

I also do not pump up the brakes. I start by 1st opening the bleeder screw and then slowly depress the brake until it bottoms out. I then close the screw while the brake is depressed. From that point on I simply depress the brake once to pressurize the system then open and quickly close the screw while under pressure and before all the pressure is gone. I continue until there is no more air coming out.

 

  Dales venture said:

Hi guys,

Going to bleeding rear brake on 92 VR shortly. I have the service manual and know the sequence to bleed (front right on it's own/ front left linked/rear brake and then proportioning valve). On the rear brake, the book says to undo caliper bolt and whilst caliper is still connected to front locating pin. rotate up 1.5 inches away from the disc and bleed as normal.

My question is that if the brake pads are away from the disc, the pistons will be forced too far out and might be difficult to force back in?

Is this correct as it is different to the way I've bled brakes on my other bikes. The others have all been bled whilst the pads have been in contact with the disc.

Advise would be gratefully received from an English cousin.

Thanks.

Blake

The only purpose for tipping up the caliper would be because in its mounted position the bleed screw is not the highest point so to ensure that the bleeder screw is the highest point for the air to go to you would have to tip it up in order to ensure you get all the air out.