Shimano bleed block width

[DMan]

Yes throw, feel is ok, the lever is almost at max adjustment.

You need to bleed with the block in though or you'll overfill it with oil. Or you can leave the pads in but don't get oil on them. But it should help it bite in earlier with a good bleed to get rid of the air instead of feeling spongy. Assuming it is air of course and not another issue.

 

[Duane]

I find the best results are to bleed with the block then a small manual pad advance.
I'm quite fussy and prefer brakes with a close lever and short throw.

 

[mark22]

Cool thanks for your help guys

 

[effarr]

^^^^^^^^^^^^^^^^^^^^^^^

What Duane said!! :second:

 

[DMan]

I find the best results are to bleed with the block then a small manual pad advance.
I'm quite fussy and prefer brakes with a close lever and short throw.

What do you mean by "small manual pad advance"? Extra bleed with the pads in? Or use a smaller width block?

 

[Duane]

What do you mean by "small manual pad advance"? Extra bleed with the pads in? Or use a smaller width block?

After you have finished the bleed.
With wheel out, pads in, give the lever a gentle 2 or 3 pumps, watching the pads carefully, the goal is to advance them out a mm or so reducing the pad to discuss clearance. Refit wheel.
You may need to recentre the caliper and getting even clearance will be more finicky with less clearance to compensate for slightly warped/bent discs.
If you go too far it's best to spread the pistons back out. I like the sram spread tool rather than butchers screwdriver but both work.
With the pads advanced this way less fluid needs to be displaced before contact so you end up with less free travel.
You can achieve a similar thing by bleeding with old pads etc instead of bleed blocks but you end up overfilling with fluid and when things expand and get hot you risk having worse performance.

Because I'm very fussy with my brakes I tend to adjust them often to maintain the perfect lever.
I have XT/SLX, ZEE, RS, RSC and Codes and use the same method for all of them.
Some of the better pad contact adjustable levers make the fine tuning easier but I still give them a bit of "manual advance" to get that ultra short lever throw I like. Having good straight discs is important though or you will forever be chasing rubbing problems.

 

[DMan]

After you have finished the bleed.
With wheel out, pads in, give the lever a gentle 2 or 3 pumps, watching the pads carefully, the goal is to advance them out a mm or so reducing the pad to discuss clearance. Refit wheel.
You may need to recentre the caliper and getting even clearance will be more finicky with less clearance to compensate for slightly warped/bent discs.
If you go too far it's best to spread the pistons back out. I like the sram spread tool rather than butchers screwdriver but both work.
With the pads advanced this way less fluid needs to be displaced before contact so you end up with less free travel.
You can achieve a similar thing by bleeding with old pads etc instead of bleed blocks but you end up overfilling with fluid and when things expand and get hot you risk having worse performance.

Because I'm very fussy with my brakes I tend to adjust them often to maintain the perfect lever.
I have XT/SLX, ZEE, RS, RSC and Codes and use the same method for all of them.
Some of the better pad contact adjustable levers make the fine tuning easier but I still give them a bit of "manual advance" to get that ultra short lever throw I like. Having good straight discs is important though or you will forever be chasing rubbing problems.

So do you do this micro pad movement before removing the bleed funnel and putting the master cylinder screw back in? Then retop the cylinder?

 

[Duane]

So do you do this micro pad movement before removing the bleed funnel and putting the master cylinder screw back in? Then retop the cylinder?

Not usually. There are exceptions but if you bled it properly there should be no need. Seal the system first beforehand, that's why most hydraulic brake systems have a diaphragm in the reservoir.

 

[DMan]

Not usually. There are exceptions but if you bled it properly there should be no need. Seal the system first beforehand, that's why most hydraulic brake systems have a diaphragm in the reservoir.

I'm not following how this works because I'm a dumbass. I can understand how bleeding with old pads instead of a bleed bock would potentially do this. But if you've bled the system with a bleed block but then "locked it up" so it's a closed system then how is pumping the lever to make the piston come out a bit before fitting the wheel any different to fitting the wheel and doing the same thing? I'm not trying to be a smartass, I just don't understand ( I'm not super mechanically minded sorry). If you still had the system open so it could draw a little more fluid in to set the piston closer to the pad before shutting it up I'd get it? Or does it sort of set the contact distance if you do what you said?
I'll happily try it mind you..

 

[andrew9]

I'm not following how this works because I'm a dumbass. I can understand how bleeding with old pads instead of a bleed bock would potentially do this. But if you've bled the system with a bleed block but then "locked it up" so it's a closed system then how is pumping the lever to make the piston come out a bit before fitting the wheel any different to fitting the wheel and doing the same thing? I'm not trying to be a smartass, I just don't understand ( I'm not super mechanically minded sorry). If you still had the system open so it could draw a little more fluid in to set the piston closer to the pad before shutting it up I'd get it? Or does it sort of set the contact distance if you do what you said?
I'll happily try it mind you..

If the wheel is fitted the brake will automatically adjust clearance relative to the thickness of the current disk, leaving 1mm clearance (1mm is a guess). Without the disk there, you could say it's like the the brake is trying to adjust to a thinner disk, so when you put the wheel back in you might end up with 0.5mm clearance.
You would have to watch closely, they will adjust to the point the the disk wont fit any more, if you let them.
If you don't take the wheel out, you can't reduce the clearance to less than the standard 1mm (or whatever it is, I've not measured).

That's my understanding, I don't do it myself, but have seen what my brakes do when I pump them with no wheel in.

 

[DMan]

If the wheel is fitted the brake will automatically adjust clearance relative to the thickness of the current disk, leaving 1mm clearance (1mm is a guess). Without the disk there, you could say it's like the the brake is trying to adjust to a thinner disk, so when you put the wheel back in you might end up with 0.5mm clearance.
You would have to watch closely, they will adjust to the point the the disk wont fit any more, if you let them.
If you don't take the wheel out, you can't reduce the clearance to less than the standard 1mm (or whatever it is, I've not measured).

That's my understanding, I don't do it myself, but have seen what my brakes do when I pump them with no wheel in.

Ahh ok. Makes sense. I'll definitely give it a try. Here's hoping my rotors are true...

 

[stirk]

Ahh ok. Makes sense. I'll definitely give it a try. Here's hoping my rotors are true...

Pads sit so close to the rotor following normal bleed procedure you should be able to tell now if your rotor is bent.



Anyone have heat expansion issues doing this beyond normal piston advancement??

 

[Duane]

Pads sit so close to the rotor following normal bleed procedure you should be able to tell now if your rotor is bent.



Anyone have heat expansion issues doing this beyond normal piston advancement??

Only experienced problems when overfilling the fluid by bleeding without the block or air still in the system(poor bleed) or contaminated fluid(old/moisture/dirty), not counting cooked pad/discs.