[Closed] Shimano ROAD disc brake bleeding - whats your tips & technique??

Mine a perfectly bled but have miles of throw. This can be adjusted depending what version you have.

I have 785s and you unscrew the silver cap to get to the adjusters.

Ultegra R8020 levers with RS785 Calipers.

When pushing fluid through from the caliper give the syringe some sharp pushes. I've found that this can dislodge bubbles that don't come out otherwise.  Also, if you have the bike in a stand with the front pointing down slightly then the hose will be above the lever as it follows the handlebars which can trap bubbles.

I've got rs785 levers and they do have quite a lot of free travel but they are pretty firm once they do bite.

8020 have free throw adjustment so you may want to check that out.

I was told from a LBS that when a set of shimano hydraulic road brakes are bled they are never as good again. He mentioned either they aren’t as firm as before, or they blow the seals ... I initially was a bit weary of what he said - although seems he may know something after all.

Same loads travel pull nearly to bar but are perfect stoppers. I’ve just learnt to embrace their feel.

I made the yellow block smaller, shaved 1 or 2 mm.

I was told from a LBS that when a set of shimano hydraulic road brakes are bled they are never as good again. He mentioned either they aren’t as firm as before, or they blow the seals … I initially was a bit weary of what he said – although seems he may know something after all.

Or the lbs are crap and they can’t bleed brakes correcty.

utter bull crap.

i absolutely hate bleeding brakes but did did my Di2 ultegras when I shortened my internally routed front.

Very easy to do and feels exactly the same as the factory spec rear.

Yeah sounds like utter nonsense. Mine came with no fluid in them. Does that mean that they'll never work properly?

It will be the hose. Stock shinano hydros are fitted with bh59 hose which apparently is to improve the modulation and feel (they expand more under pressure).

I swapped the hose after reading a tip online to the bh90 hose (mtb slx / xt etc) and bled. The difference was incredible... Firm lever and great performance. Did find they were a tad grabby though so dropped a disc size to compensate (180 to 160). Perfect now... Really was not happy with them before swapping the hose. Would pull back to bar and just felt bad.

I know this one! (cchris2lou has it)

Bleed them with no spacer between the pads (or if you are taking the pads out, a smaller gap than pads+rotor between the pistons). When bled you can push the pistons out to make enough space for the rotor and you get a much better bite point. Works for me anyway.

(Hose option above is interesting, might try that next time (probably a couple of years time!))

There will be air still in the system somewhere, tap the caliper, lever head and hose with an allen key when bleeding to force any trapped air bubbles upwards

Also as said above shave the bleed block down by 1-2mm and then once bled the lever will engage much sooner

Dont pump the lever, bleed upwards only, once your sure all the air is removed refit the lever's grub screw then push more fluid into the caliper and lock off the bleed nipple

Done this on three sets of R785 levers with BH59 and BH90 hoses, all three bikes brakes felt great afterwards

It is "easy" to trap air in the system. Rear brake caliper often needs removed from the mount and let it hang down to get all the air out the caliper. Adjust the angle of the bike in the stand to remove adjust points, adjust the STI angle, one the caliper and hose is bleed you need to get all the air out the master cylinder resevoir, normally easiest my repeadedtly pulling and releasing the brake lever and moving the STI to different angles (imagine rolling the air bubble about inside the lever and getting it to line up with the hole).

You can push with a syringe, traditional pull open close, gravity bleed etc, all you need to do is get all the air out.

And yes bullshit on the never the same again, thats just somebody that cant get all the air out.

Good tip regarding shaving the yellow block.

i fitted uberbike XL pads instead to get the same result. ( the XL pads are slighty thicker )

Assuming you've got an open syringe or cup at the top, a fluid saving trick is to push fluid through from the bottom and then when you've used up almost all the fluid in the lower syringe, close the bleed port, disconnect, suck the fluid out of the top and repeat.  Obviously don't do it if the fluid coming out of the top is old and manky, but if it's clean you can keep pushing the same fluid through repeatedly until you get all the air out.  When reconnecting, suck before you push.

Agree with bigyan, there's no black magic here, you just need to get the air out.

According to Shimano's compatibility chart, R8020 levers should only use the BH90 hose (silver insert) no mater the caliper (785 included).

All being said when bleeding them especially the back one I pump lever with bleed open.

I know this can draw air in but it dislodges any air bubbles and once most are removed and bleed valve closed lever firms up pretty quickly.

Also when good bleed achieved pull lever in when wheel

is out.

Not fully but closes pads in then try wheel and repeat.

It moves the bite point closer.

You might find the disc rubs a bit to start as the pads are closer but this soon disappears and you find you have quite firm braking.

Max