Bike Pump Brake Caliper Piston Removal

[ColdSteelWillHeal]

I've been rebuilding my brakes and have seen many threads saying use a bike pump if you don't have an air gun. Not many of those threads really showed how to do it and those that did used that conical ball pump gadget jammed into the brake line opening. I haven't seen this method in any forums so I thought I'd share.

The bleeder valve on most brake calipers is sized very similarly to a Presta bike valve. An old brake line can be threaded onto a caliper and clamped to prevent the air pressure from escaping. Any bike pump can then be used to pressurize the piston via the bleeder valve. I ended up using about 60 psi to push the caliper out a reasonable speed.


The bike pump and clamp apparatus.

[ColdSteelWillHeal]

Here's a really terrible video of the piston coming out. It was raining and the shed has a tin roof and an iPhone speaker is great at picking up the extra noise.

https://www.youtube.com/watch?v=WhxKA2NjXdo

[Bearmw]

I've used a bike pump too and it works well. Helpful thread:)

[kungfooren]

What a coincidence. Just did this today and it also took a few pumps at ~60 psi to push the piston out. Hardest part is getting the plastic pump needle to seal but it's a one man/woman job.

[ColdSteelWillHeal]

What a coincidence. Just did this today and it also took a few pumps at ~60 psi to push the piston out. Hardest part is getting the plastic pump needle to seal but it's a one man/woman job.

Instead of the plastic tube use a bike pump right onto the bleeder valve. Use a clamp on an old piece of brake line to keep the system sealed like in the fist pic. That way you're not trying to jam in a piece of plastic with one hand and pump with the other.