leaking hydraulic brake calliper

[Milkfloat]

Basically yes - remove, refit, fill and bleed. I would drain out all the existing fluid so you start totally fresh.

 

[alecstilleyedye]

how much fluid do I need?

 

[Milkfloat]

how much fluid do I need?

50ml would be more than enough and you could even afford to sacrifice some to flush out any crap.

 

[fossyant]

Not much - depends upon if you get air in it too. Fairly simple though.

 

[si_c]

50ml is probably more than enough, but it is good to drain the fluid entirely first though. You can then push new fluid from the caliper.

 

[alecstilleyedye]

so fill from the bottom and degas from the top then...

 

[si_c]

so fill from the bottom and degas from the top then...

That's the way I always do it when filling fresh. Filling from the bottom helps push any air bubbles upwards to the top, and out the shifter. I usually use the bleed cup at the top to collect the fluid as it comes through as it helps make the whole process a bit easier.

 

[Ming the Merciless]

how much fluid do I need?

Front or rear? Rear has longer hose and therefore slightly more fluid. But it’s approx 25 mL per brake, with a little more than that used during bleeding to ensure you don’t introduce air back into the system.

 

[BianchiVirgin]

I have had problems with 105 callipers. One, like your where the seals just seem to leak no matter what I tried, another where the screw holding the pads in was totally seized, this screw is made of cheese and not even hard cheese, more like cream cheese. In both cases I just bought new callipers as there was nothing I could do to rescue them, even with disassembly.

Yes, had this cheese issue too. One area where Shimano are very poor. Calipers are crap. Period.

 

[I like Skol]

Yes, had this cheese issue too. One area where Shimano are very poor. Calipers are crap. Period.

You say that, but have you ever used Tektro hydraulics? I suffered them once, Shimano are Rolls Royce in comparison!

 

[BianchiVirgin]

You say that, but have you ever used Tektro hydraulics? I suffered them once, Shimano are Rolls Royce in comparison!

Eh no, but judging by the mech ones I've seen I can imagine. I had 7000 series 105 on a new Cube and they were just pure dung. From constant squealing to lousy feel. And the cheese pad screw was the last straw.

 

[alecstilleyedye]

I have had problems with 105 callipers. One, like your where the seals just seem to leak no matter what I tried, another where the screw holding the pads in was totally seized, this screw is made of cheese and not even hard cheese, more like cream cheese. In both cases I just bought new callipers as there was nothing I could do to rescue them, even with disassembly.

the drilling out of the screws is where this all started...

 

[alecstilleyedye]

well I've decided to take the plunge and replace the calliper myself. thanks to all for advice.

I was going to let lbs do it but have decided to spend the money (£30 plus surcharge for providing own component) on more oil and a bike maintenance stand. suffice to say I will be swapping the screw out for a split pin.

I'll let you know how I get on

 

[BianchiVirgin]

well I've decided to take the plunge and replace the calliper myself. thanks to all for advice.

I was going to let lbs do it but have decided to spend the money (£30 plus surcharge for providing own component) on more oil and a bike maintenance stand. suffice to say I will be swapping the screw out for a split pin.

I'll let you know how I get on

You can get Allen key head screws, normally black, that are much better that those slot head junk. And better than split pins.

 

[fossyant]

You can get Allen key head screws, normally black, that are much better that those slot head junk. And better than split pins.

That's what's on my SRAM Guide RS's - far better than split pins.