Why cant I bleed brakes?

gtd.

I can never seem to bleed my brakes well

Tried bleeding my brakes as the hope video but that doesn't work well, tried pressure bleeding and there still not right.

Managed to get the back Mono Mini spot on by pressure bleeding then using a Hayes bottle on the nipple,opening it pump the lever till there was no bubbles in the pipe then squeeze fluid back into the calliper then nip it up.

The rear mono mini feels great now but the front one which is a Mono M4 doesn't.

Tried bleeding it as shown in the hope video but its still spongy and I tried putting extra fluid in like on the rear brake but that didn't improve it either.

Do I need new seals or something as I'm getting no where with it.

peter413

Is your caliper properly aligned and have you allowed the brakes to bed in?

nicklouse

you are pushing the pistons home and holding them there when you bleed the brakes.

you are then allowing the pistons to reset after bleeding.

gtd.

Caliper is a aligned and brakes bedded in

nicklouse wrote:

you are pushing the pistons home and holding them there when you bleed the brakes.

you are then allowing the pistons to reset after bleeding.

Yep to both little bit of wood in between the pistons then pump the lever so the n pads reach the disc.

They always have excessive travel, when I added fluid in from the nipple of the mono mini it felt much better instant response and firm lever feel cant get the front Mono M4 the same though :?

nicklouse

in that case you are not really finishing the bleed that well.

with pistons home bleed till no bubbles. then tighten nipple reset pads rotor etc and pump lever topping up as needed. when lever is right fill flush and roll the diaphragm and fit cap. sorted.

if you cant get it to feel right there is still air in there.

gtd.

It still feels like there's air in there when I pump the lever while the cap is off, when its bled it should be firm before I fit the diaphragm and cap?

kevolution

Sounds daft, but this works. I've bled 1000's of brakes and wrench for a Hope sponsored WC DH racer.
Adjust the lever throw adjuster (2mm allen bolt on the lever blade barrel) to about the middle, and repeat the bleed process.
I bet it works.(assuming you've lubed your pistons of course)

gtd.

Thanks guys re done them after wrapping the nipple threads with ptfe tape as they were weeping fluid slightly/letting in air :oops:

02gf74

GTD. wrote:

Thanks guys re done them after wrapping the nipple threads with ptfe tape as they were weeping fluid slightly/letting in air :oops:

hmmm, that shouldn't be the case - the nipple has a conical end that akes e seal with a smilar cne but at slightly dfferent angle; the threads don't feature i nthe sealing at all.

you sure you have the correct npples fitted or not damaged the bleed nipples or caliper?