Size of Glee brake caliper pistons?

[mrp192]

Hi, I’m trying to teach myself to do more on my 2015 Glee and my next ‘new to me’ task is to clean the front brake caliper pistons and sliders.
My mechanic has shown me a tool he uses to gently turn the piston in the caliper to clean all around it, that looks like a set of pliers that expand to grip the internal face of the piston.
I’ve found them on Amazon but they come in different sizes so I wondered if anyone knew the diameter of the internal bore of a Glee piston. My fella isn’t now available to ask for a couple of weeks so thought I would pick all your brains rather than wait to speak to him again. Thanks.

[UK_Vstrom650]

Without measuring (I'll check a spare one I have in the garage later) the front are about an inch and the rear is larger maybe 1.5-2 inches from memory.

I have one of those tools and they're good, albeit I stripped the thread from the expander bolt when trying to remove a seized piston (over tightened it). I can still use it, but need a strong grip.

[kwackboy]

Internal dimensions are around 22-23mm

[UK_Vstrom650]

Spot on as ever Kwackboy   

[mrp192]

Thank you to both of you. There are cheap ones that go quite small but reviews are rubbish. Found a good one for only slightly more but needed to know 19mm min would be OK. Will get it ordered and then have a go at cleaning the calipers.

[Gert]

One can also make use of a Bent Nose Circlip Pliers, https://5.imimg.com/data5/CX/YR/MY-3086911/circlip-pliers-bent-nose-500x500.jpg, if the correct tool is not readily available. The jaws open as you apply pressure. If you are afraid of scoring the inside of the cup, use a piece of thin leather, rubber or similar to help prevent any scoring.

[UK_Vstrom650]

Good tip on using rubber etc Gert, although mrp192, if you do score the inside of the piston it won't affect braking performance.

[endintears]

Whittle down a bit of wood and tap it gently(ish) into the internal side of the piston, probably grip enough for what I think you're trying to do.
Or does that sound a bit rough to some of you...😏

[tallpaul]

It could endintears...

[mrp192]

Thank you all for your advice. Have ordered a pair of the Draper Expert caliper pliers. Found at half price on Amazon for just under £20.
Reviews very good and same as the ones my maintenance fella uses.
If I get this right I’ll probably make a habit of doing all three calipers every Spring as I think riding in all weathers through the winter is what has caused them to get ‘grippy’.

[endintears]

Spendthrift😄

@tallpaul🤣