Hydraulic brakes binding

[mike9009]

Hi

I have a Boardman hybrid with SRAM hydraulic disk brakes. A couple of months ago the front callipers were binding. So I stripped them down, replaced the fluid (and pads) reassembled and everything seemed good in the world.

I do not do huge mileages (as I am mainly leisure cycling with the kids at the moment).

Today, the front brakes are binding again. Now this maybe coincidental, but it seems to happen whenever I put the bike on the back of the van to go somewhere to cycle. Can the speed behind the van somehow 'leak' air into the system and require it to be bled again? Is this possible?

Thanks in advance!!

Mike

[JulianHJ]

I have had similar issues with the rear brake on my bike; it was a Formula RX. It would regularly require bleeding - maybe once or twice a year. The front has been fine. I ended up fitting a Shimano replacement last week.

I don't use the bike much, and it lives in the garage, so I wondered it it was picking up air/moisture. I also stored it vertically most of the time, however during the most recent occurrence it was stored normally. The garage is integral, and not noticeably damp or cold.

Edited by JulianHJ on Sunday 7th August 18:21

[Jobbo]

Have you removed the front wheel? I go cycling with a friend who seems completely incapable of putting his front wheel back on perfectly aligned, or does something like tighten the quick-release skewer way too much so the disk always rubs. He lets me put the wheel back on now. Long shot but could this be your problem?

[mike9009]

I don't need to remove the wheel to fit on the van, so it rarely come off. However I will try reseating the front wheel before bleeding the whole system again...

I store mine in an integral garage which is dry, but has a door which is not 'sealed'. I can't understand why only the front brake is affected - hence the irrational 'when it is on the back of the van' maybe it is the positioning on the van?

[The_Jackal]

Check your rotor isnt warped.

[With these feet]

Had a set of Avids that did this. The only explanation is some king ot fluid expansion, as unlike a car system the bike is sealed, if pressure builds it will drag on the brake, on a car system the fluid returns to the reservoir.

I found the easiest way to fix was crack the fill screw on the brake lever with a tiny amount of pressure on the lever - and just open the screw enough to let a few drops of fluid out. This should allow a small amount of free play between lever and caliper.
Mop the fluid up quick, paint deosnt like brake fluid!

[gazza285]

I had a set of Avids do this, and a set of Promax on our youth's bike, after ages of tinkering on a regular basis I cured them both with an application of Shimano. No problems since.

[mike9009]

Thanks for the advice so far...

1. Check rotor is not warped.
2. Let a couple of drips of fluid out of system.
3. Replace with Shimano gear. Any recommendations? I am not a serious rider so something budget will probably suffice. I think the Avids I have are 160mm rotors - but Shimano all seem to be 140mm rotors. Do I simply need to change the rotors or are the mounting points different too?

Thanks again

Mike

[fuzzymonkey]

All discs are standard so no need to change them.
Look at some Shimano Deore brakes, nice and simple.

[JulianHJ]

Shimano discs are 160, 180 or 203mm IIRC - you can replace the caliper, but might need a Shimano post adaptor as well.

[With these feet]

Pretty sure the calipers are all the same, spacer kit to move the caliper out with longer bolts required.
The pad size is the same, only the mechanical advantage increases the further (bigger) you go.

[anonymous-user]

As above, check if you have post mount or IS, something like these will be more than adequate - http://www.ebay.co.uk/itm/2016-SHIMANO-BR-BL-M315-...

[mike9009]

Thanks again.

1. The rotor is perfectly true.
2. Three drops of fluid removed from the system seems to have worked (but for how long?)
3. I will keep my eye on the Shimano kit. (I always thought Deore was superior to SLX but my expertise in MTBs dates back to early 90s and my Deore DX short cage derailleur and Deore XT thumbshifters on my Trek 930 Single Track, which I still have but in bits.)

Mike

[anonymous-user]

mike9009 said:

Thanks again.

(I always thought Deore was superior to SLX but my expertise in MTBs dates back to early 90s)

MTB groupset's buyers guide -

http://www.bikeradar.com/gear/article/buyers-guide...