e3opian

http://www.amazon.com/Michigan-Industrial-...47768853&sr=8-4

vietboyjl

Ah yes! You are right I didn't throughly read the thread this morning, only skimmed through it as I was getting ready to leave for work.

No wonder I couldn't get the pistons to retract! Looks like it'll be another trip to the auto parts store. I had to make two trips there yesterday, one to get anti-spueak lub and the 2nd time to pick up a impact driver. The impact driver works wonders! Would've had to drill out those screws if I didn't have that driver.

Wish I had known this yesterday!

Thank you guys for your input! I'll probably get back to work on them this weekend, I'll let you guys know how it goes.

Greg W

You can also use a large flat-head screwdriver in the piston grooves off-center from where they intersect. Select a blade that's wider then the grooves, seat it in one of the grooves, and twist. I find this easier then using a 3/8" socket extension, and it takes no more torque then using the socket extension at the center. I also find it easier handling the caliper this way (you're applying a pure torque rather then a force onto a moment arm).

CKit

That thing reminded me of the Hellraiser puzzle box...


I like the 3/8th ratchet technique myself.

damuho

This is exactly how I changed my rear brake pads. I used my biggest minus screw driver which is about 5/8" wide and more than 2mm thick. Getting started with rotating the piston is the hard part but once you get going, it is easy and fast. Think of it as if you are "screwing" the piston back into the cylinder.

Good luck!

AusS2000

I've changed my rear pads many times but I'm still unsure how the rear pistons work and why you screw them back in (when the fronts just push). Does it unscrew when you apply the brakes?

Anyone know a web page that shows how a rear caliper works?

SpitfireS

Its all because of the e-brake system "embedded" in the rear caliper.
That system is mechanical, meaning there is a mechanical link between the piston and the the e-brake handle and it has an auto pad wear adjuster system.

In short:

When you apply the e-brake you push the rear pistons out mechanically, but it has a limited stroke.
There has to be a system to compensate for pad wear otherwise the limited mechanical stroke - at some point - can not push the pad against the rotor anymore.
That is why the rear piston has internal thread and it screws on an actuator spindle.


This is the e-brake actuator spindle in the caliper.
It mechanically pushes the piston out when you apply the e-brake AND unscrews itself one-way to compensate for pad wear.
IOW it makes the piston stay out a little more and not retract when the hydraulic pressure is gone.
And that is why you HAVE to screw it back in.
Clockwise

I had the rear caliper apart a while back and "kinda" understood how it works.

More pics here:
https://www.s2ki.com/forums/index.php?showtopic=672065

Dynamiteboy

[QUOTE=Greg W,Jul 16 2009, 01:33 PM] You can also use a large flat-head screwdriver in the piston grooves off-center from where they intersect.

AusS2000

Thanks Spitfire, makes perfect sense.