Brake bleeding Q

[Willam]

Quick question, I’ve only bleed my breaks once before, shamino mt200, bleed and changed the rotors and the pads, is it normal for the pads to rub on the rotors a little, there was hardly a gap for the rotor, had to push the wheel back in, think I did everything correctly? I even loosed the brake mounts, pressed in the level then retightened them.
Wondering if I have missed something? Or is a little rubbing expected?

 

[SolemnWeasel]

Should be fine, however when you were swapping the pads, did you push the calipers back in? With a screwdriver for example.

 

[Willam]

Should be fine, however when you were swapping the pads, did you push the calipers back in? With a screwdriver for example.

Yeah I also used a brake block…the one thing I did do differently to some videos was use the syringe to pull the old oil out rather than push new oil in with the syringe? Shouldn’t matter I’m thinking? I was just a little surprised to see next to no gap between the pads for the rotor?

 

[Willam]

Anyone explain why when I have bleed the brake and replaced the pads, job done, the lever no pressure to it, I have to remove the screw from the lever again and pump the lever a few times with the oil barrel in place, the level then has the pressure back?

 

[Yellow Saddle]

Anyone explain why when I have bleed the brake and replaced the pads, job done, the lever no pressure to it, I have to remove the screw from the lever again and pump the lever a few times with the oil barrel in place, the level then has the pressure back?

They weren't bled properly. There is still air in the system.

 

[Willam]

They weren't bled properly. There is still air in the system.

Bleeding looks easy to be fair but obviously a lot can go wrong and it doesn’t help that virtually every video I watch on this does it a slightly different way…think I got there in the end.

 

[fossyant]

Epic Bleed Solutions do some good guides for all makes.

 

[I like Skol]

May I ask why you are bleeding the brakes?

 

[Willam]

May I ask why you are bleeding the brakes?

Good question…I guess as I was changing rotors, pads and the brakes hadnt been bled previously from new (2 years) I thought it was the right thing to do?

Just noticed one of the front caliper pistons is no longer moving when I press the lever, just about to try another bleed to see if that fixes it, if no think I might just go for some new m6100, at £100 seems worth an upgrade from the mt200, especially if they are not working fully…oh and when I went out last night to bed in the pads I’m nearly sure some oil was leaking from both levers, just a tiny amount, it could be left over oil from the bleed maybe,? so something to keep an eye on.

Came across a tip about not over filling the brakes, apparently opening the lever bleed valve before pushing the pistons back in prevents that from happening, dont think I did that so might explain the potential leak from the levers?

 

[I like Skol]

Too late now, but for future reference to anyone else who finds this thread.....

Shimano hydraulic brakes use mineral oil. This is a stable, relatively inert fluid, which unlike car DOT type brake fluids, does not really absorb moisture or degrade over time. This means you do not need to routinely replace the fluid or bleed the system. If it's working, leave it alone, or you risk messing it up....

 

[Willam]

Too late now, but for future reference to anyone else who finds this thread.....

Shimano hydraulic brakes use mineral oil. This is a stable, relatively inert fluid, which unlike car DOT type brake fluids, does not really absorb moisture or degrade over time. This means you do not need to routinely replace the fluid or bleed the system. If it's working, leave it alone, or you risk messing it up....

Good advice, though a question, if replacing pads and rotors would a bleed be necessary?

Just finished a 2nd bleed on the frond and the wheel is new free rolling and the pads are not pushing the rotor to one side as previously so seems to have got me back to where I was at the start

 

[Ming the Merciless]

Good advice, though a question, if replacing pads and rotors would a bleed be necessary?

Not necessarily. Replace the bits that need replacing and check the brakes. Generally you only need a bleed if the brakes have gone spongy in feel, and you haven’t pushed pads and rotors beyond their minimum wear limits.

 

[Willam]

Epic Bleed Solutions do some good guides for all makes.

Checked them out, they have only basically copied and pasted shimano’s manual.

 

[T4tomo]

Too late now, but for future reference to anyone else who finds this thread.....

Shimano hydraulic brakes use mineral oil. This is a stable, relatively inert fluid, which unlike car DOT type brake fluids, does not really absorb moisture or degrade over time. This means you do not need to routinely replace the fluid or bleed the system. If it's working, leave it alone, or you risk messing it up....

Very sagely advice! I have change pads a few times on my ?10 yr old gravel bike (which has some old TPR Hylex) but never needed to bled them. just wiggle the pistons back a bit and pump the levers a couple of times once all back assembled.

 

[C R]

Checked them out, they have only basically copied and pasted shimano’s manual.

Shimano's manuals are very good, among the best I have found over thirty years of working with all kinds of equipment.