Shimano caliper problem.

[Chet Spiker]

Hello. My Orange hybrid has a problem with the rear hydraulic caliper (Shimano Deore BR-M6000) in that the outboard piston does not retract as it should and therefore continually rubs the pad against the rotor. I have cleaned the caliper and lubricated the piston with mineral oil but still it won't retract. Trying to push it back in with a plastic tyre lever is very hard unless I fit the bleed funnel to the brake lever to open the system - the piston will then push back in quite easily. I have repeated this procedure at least ten times so I'm sure the piston is clean and lubricated but the little blighter still won't retract under its own steam. I watched a SickBiker video where he opened up the caliper and replaced the pistons and seals but have been unable to find a supplier for these parts. Does anyone know of a supplier? I would have ordered a M6100 caliper from Wiggle but they are out of stock. Thanks in advance.

 

[weareHKR]

It will be difficult to push back when the system is closed as you are pushing against the hydraulics, so you've done the correct thing by opening it up & working it in & out.
Sounds like you've done the right things already. Have you made sure the rotor is true?
The spare parts I guess should be available from Shimano!
Someone else with more experience of bike disc brakes might be able to give you further advice, I'm still olds school rim brake guy...

 

[Chet Spiker]

Having spent much of the morning searching online it seems that Shimano, unlike Hope and a few others, don't offer component parts only whole calipers. Thats not really a problem as the new caliper comes with new pads but the one I need is out of stock in all the usual big retailers. This is the problem with only having one bike!

 

[keithmac]

There are muliple calipers that will fit in place.

My Shimano hydraulics vent back to the reservoir with the lever released, same as motorcycle calipers, if it didn't they would bind up when it gets hot.

You should be able to push the pistons back without releasing blead nipples. My lads Tektro? Hydraulic sytem is the same.

 

[Chet Spiker]

Thanks, Keithmac - I suspected there would be other compatible units. I found a seller on ebay selling the complete Shimano brake for £58 although of course I don't need the lever. I'll give it another couple of days to see if they come into stock.

 

[confusedcyclist]

Try ask you local shop who should be able to obtain the spares you need, but the price may not be economical. You could always buy the complete brake and sell the components you don't need, or keep them as spares? Just check ebay completed sales to see how often they sell first to see if there are enough buyers for your liking.

 

[keithmac]

I rebuild motorcycle calipers due to cost reasons mainly, I'd just replace the cycle one as a unit personally (cost vs time).

 

[Chet Spiker]

Thanks, everyone. I've ordered a complete brake from wiggle - the M7100 version so a slight upgrade. Should be here Friday so will update when fitted.

 

[Chet Spiker]

Okay, all sorted. The new brake arrived yesterday so I spent an hour in the shed fitting and filling it. Went for a 20k run this afternoon and it was fine although it needs a quick bleed now to get the last few air bubbles out.