more front brake weirdness - tip seeking

[echoyankee]

Hello all:



Wrestling with my first brake pad change (front end) and have become hung up on one of the steps in the procedure.  



Good bits:

I have successfully

-removed caliper

-removed retaining pin

-extracted old brake pads

-pushed back pistons

-reinstalled new pads

-replaced/reinstalled retaining pin





Here's where I'm getting hung up.



I want to now put the caliper back, but the new brake pads, thick with beefy newness, permit about 1mm clearance between them.  Not enough to get the disc/rotor back between them.  



Now, I thought I'd not pushed the pistons back sufficiently, so I swapped the old/used pads back into the caliper pried the old ones out/open with a screwdriver (biggun).  I looked over my results and knew that this wasn't going to cut it, so I cracked the bleed valve open and got some drippage and made a bit more progress with the piston pushback, but not enough.  



The bike sits, one caliper dangling with about a 1mm clearance between the new pads.  



There's GOT to be an easier way that this brake pad swap virgin doesn't know about.  



Any tips from you do-it-yourself ers out there?



Thanks in advance,



echoyankee

[iansoady]

You normally need to push the pistons back till their outer ends are more or less flush with the face of the caliper. I find a tyre lever against a soft bit of wood helps. Slackening off the bleed nipple will let them move more easily. If they don't retract smoothly and easily then I'd suggest you have some corrosion / muck in there and it would be a good idea to strip it all out & clean it up as well as fitting new seals. Not too difficult a job (probalby 2.5 Haynes spanners......)

[Jim S]

Can I just add that after much dealings with Honda's nissin calipers on the africa twins if they are tightening up with you best to remove the pistons and seals and clean and rebuild them. If not, you run a high risk of warping discs. If you're unsure, ask someone you know and trust to have a look at them, it's just not worth the gamble of having sticky calipers causing the discs to heat and warp!

Hope this helps you.

[Guest]

Just a thought.....have you DEFINATELY got the right pads?

Only, I've had a case on a car where the pads were the right shape BUT were for a different vehicle which had thinner discs.



Other than that, I replaced mine recently and all fitted OK. The pistons have to almost dissappear into the caliper body.

[echoyankee]

This got resolved pre-weekend.



I took the lid off the master cylinder and pushback was much easier and very straightforward.  



The OEM triumph pads went in and the calipers are back on the rotors.  



Now I just need to bleed and pump them up.

[steveb]

As you did not remove the pistons, no air could have got into the system, so no need to bleed, just operate the lever a few times to bring the pads up to the discs!

[echoyankee]

Oh no, no, no.



I snarfed some air into the lines in the course of the project letting my master cylinder get too low.  (d'OH!)



I gotta bleed the lines.



If it weren't for that, yes, I'd say just pumping them back up would do the trick!



Best,



echoyankee