The hacks and bodges thread

[RustyMTB]

Thought this could be a useful spot for those of us who don't mind getting our hands dirty.

My acoustic hard tail has a seized front caliper. Nothing special, just a Deore two pot but I'm attached to the old girl & like to repair rather than replace. So, lacking an air compressor but needing to get the pistons out, I reasoned I could use a bleeding syringe to push the pistons out with incompressible water.

Sure enough it worked but one piston was stuck good, so I used two cable ties to hold the free moving piston in place & concentrate all the pressure on the stuck one. Worked like a charm & let me split the caliper, clean & lube the pistons & reassemble. There's always a way!

 

[Spangoolies]

Thought this could be a useful spot for those of us who don't mind getting our hands dirty.

My acoustic hard tail has a seized front caliper. Nothing special, just a Deore two pot but I'm attached to the old girl & like to repair rather than replace. So, lacking an air compressor but needing to get the pistons out, I reasoned I could use a bleeding syringe to push the pistons out with incompressible water.

Sure enough it worked but one piston was stuck good, so I used two cable ties to hold the free moving piston in place & concentrate all the pressure on the stuck one. Worked like a charm & let me split the caliper, clean & lube the pistons & reassemble. There's always a way!
View attachment 105228 View attachment 105229 View attachment 105230

One of the things I liked about Hope brakes is you can fit a shock pump on the threaded part of the hose fitting and pump the pistons out as you can’t really fit a syringe under reasonable pressure on the bleed nipple

 

[Eliadn]

I would have rigged some attachment for a hand pump instead of using water. Or lubed the piston from outside somehow. But good results anyway!

 

[Stihldog]

Pass the popcorn please! I like this idea. We don’t have every tool or technique, but there can be more than one method to bleed the brakes.

 

[RustyMTB]

One of the things I liked about Hope brakes is you can fit a shock pump on the threaded part of the hose fitting and pump the pistons out as you can’t really fit a syringe under reasonable pressure on the bleed nipple

Pays to take great care with Hope pistons. They're made of phenolic resin material & very easy to chip.

 

[Spangoolies]

Pays to take great care with Hope pistons. They're made of phenolic resin material & very easy to chip.

Yup, chipped one on my first set and treated them like glass after that. Think they are using steel on the new range.

 

[steve_sordy]

I thought brake fluid was incompressible?

 

[RustyMTB]

Well, it's a Shimano caliper, so it doesn't take brake fluid. Are you new here?

 

[steve_sordy]

Well, it's a Shimano caliper, so it doesn't take brake fluid. Are you new here?

If I had said "Shimano mineral oil brake fluid" would you have been happier?

Mineral Oil Brake Fluid (1 Litre)

Buy your Shimano Mineral Oil Brake Fluid (1 Litre) - Brake Oils from Wiggle. Our price £24.99. Free worldwide delivery available.

www.wiggle.co.uk

Same point:

Is Shimano mineral oil brake fluid incompressible? It works in brakes, so it must be highly incompressible, if not perfectly so.

 

[RustyMTB]

Yes but the specific context in this thread is me pushing fluid through a demounted caliper stood at the sink whilst holding my thumb over the brake line inlet in order to stop it gushing everywhere, that one way or the other is going to escape under pressure anyway. Therefore, water. This is a perfect example of what could work vs what is a very silly idea