Lazy Brake Pistons..

[silentRVF]

Hey guys,

I had to take my front wheel off so I decided to clean my front brakes while i was at it.

RHS Caliper: When I took the pads out I noticed the pistons weren't all pushed out the same distance.. I pushed them all back almost all the way, and squeezed the brake lever. One piston moved alot, one piston moved less, and the other 2 only flinched..

LHS Caliper: Even worse.. 1 piston moved alot. The other 3 would move minimally when the lever was squeezed. After cleaning the pistons with brake cleaner and a toothbrush for a few minutes one of the other pistons started moving a bit more.. The other 2 were still being lazy..

I'm assuming this isn't normal.. How would I fix it?

Funnily enough, all 4 pads are worn evenly. And my brakes are more powerful than my old bike (CBR250RR), but
I'm assuming if I rectify the problem they would be much better..

Thanks
PS: I installed the shim on top of my rear shock mount and although I only got to ride about 1 minute before my bike died, I could definitely tell the difference in the ride height. Can anyone explain briefly how such a small shim makes such a big difference (eBay listing says the 3mm shim makes a 11mm difference) in the ride height and handling (I've read on here that this shim makes the handling alot better on the RVF)?

[Neosophist]

There probably ok.

Don't forget you had no resistance on them, the easiest to move piston will always move first.

If you clamp one of the pistons in, say with a tight fitting cable tie, the other piston will then come out, this is what happens when it presses against the brake disc.

As long as both of the pads are wearing ok it sounds normal.

[silentRVF]

OK cheers mate

[Cammo]

+1 to Neo's comment, nothing wrong with the brake pistons if they're working well.

Can anyone explain briefly how such a small shim makes such a big difference (eBay listing says the 3mm shim makes a 11mm difference) in the ride height and handling (I've read on here that this shim makes the handling alot better on the RVF)?

Raising the rear will improve the handling, the NC's sit a bit too low as standard and as a result are a bit lazy to turn in (but are very stable). Changing the geometry as you have will quicken up the steering a little and make the bike happier to turn in.

It's an essential mod IMO to an NC, and cheap. Shims will only work on rvf's but you can redrill the vfr lower link for the same effect.

[silentRVF]

Thanks Cammo. Will hopefully have time to go for a ride this arvo to test out the new tyres and the raised height!
We're starting to get some nice 23-24 degree days here finally Hope it's the same in your part of the country

EDIT: Another question.. I stripped the hell out of the brake pad pin plugs and had to drill into them and use an extractor to take them out.. Do these serve any purpose other than to keep the dust from getting to the brake pad pin? Should I bother replacing them?

[Cammo]

EDIT: Another question.. I stripped the hell out of the brake pad pin plugs and had to drill into them and use an extractor to take them out.. Do these serve any purpose other than to keep the dust from getting to the brake pad pin? Should I bother replacing them?

Do you mean the short, wide grub screws? If so they can be a right pain, I've wrecked them in the past trying to get them off also. You don't strictly need them but they may act as a safety measure (unlikely that the pad pin will come out though!).

For peace of mind it's probably sensible to replace them with new ones, David Silver site should have them. Perhaps apply a little high temp (copper) grease to the thread so they don't sieze up any in future.

Warming up nicely here also - bring on Summer!

[superlite]

Do you mean the short, wide grub screws? If so they can be a right pain, I've wrecked them in the past trying to get them off also. You don't strictly need them but they may act as a safety measure (unlikely that the pad pin will come out though!)

I've wrecked them in the past too and just run without them.

Bring on the heat

[Spoonman]

They're cheap enough, so I'd replace them.

An impact head in an airgun shifts them no hassle for future reference.