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Brakes
A1 - 3/12/08 at 11:13 PM

em...if youve been a bit stupid and bled your brakes without putting them on the discs (rear sierra callipers) and the pistons pushed out, whats the best way of getting it back in?ive tried a few things involving clamps but no success


blakep82 - 3/12/08 at 11:17 PM

you have to screw them in, but i've looked at my calipers, i don't know how its done, but thats how its done.

admittedly not the most helpful answer you'll get, but don't try and force them


markyb - 3/12/08 at 11:27 PM

with a grinder you have a tool that you use to change the disc - I used this tool to wind back the caliper as it was a perfect fit


blakep82 - 3/12/08 at 11:34 PM

is it the actual piston you wind in? i couldn't find anything else to wind


A1 - 3/12/08 at 11:40 PM

ive tried screwing in the pistons with g clamps, thats always worked before on other cars...seems rock solid...


blakep82 - 3/12/08 at 11:41 PM

noooo you have to turn the piston i think. not just push it back in


A1 - 3/12/08 at 11:46 PM

aah! ill try that tomorrow! cheers!!


Chippy - 3/12/08 at 11:52 PM

Makes it a bit easier if you use the "g" clamp and turn the piston as well, at least thats how I always do them. Cheers Ray


StevenB - 3/12/08 at 11:54 PM

Do not apply anymore direct pressure to your piston.

The face of the piston has 2 notches on either side
across the diameter.
A wind back tool has pins in a matching pattern to grip the piston.

Pic attached of a draper version.

They can take a bit of shifting to get them started. But usually fairly easy. Ive seen people use long nose pliers.

Cheers

Steve Rescued attachment wind back.jpg
Rescued attachment wind back.jpg


britishtrident - 4/12/08 at 08:51 AM

Never force back pistons on rear calipers with an integral hand brake --- many calipers have been ruined this way.

The Draper or the very similar Sykes-Pickavant tools should only be used with care I know of a case where a well known fast fit oufit ruined the rear calipers on a Volvo with one of these which they used incorrectly. G clamps won't do anything but break the self adjuster.


.The pistons just need screwed in combined firm push. Also the handbrake cable should be fully slack.


Usually all that is required is one of these piston cubes
http://www.agriemach.com/product_info.php?cPath=0_63&products_id=753

[Edited on 4/12/08 by britishtrident]

[Edited on 4/12/08 by britishtrident] Rescued attachment B50_DISC_BRK_PISTON_1455.jpg
Rescued attachment B50_DISC_BRK_PISTON_1455.jpg


adithorp - 4/12/08 at 09:18 AM

Wind them back as Above^^^

Once they're back on don't pull the handbrake lever untill you've pumped the pistons out with the foot brake or you can fook the mechanism.

adrian


Roman - 4/12/08 at 09:37 AM

Also undo the cap on the master cylinder, when winding back check it doesn't overflow.

Don't forget to re tighten the cap once finished..


Vindi_andy - 4/12/08 at 04:50 PM

As previously metioned on here a angle grinder disc spanner works well the type with the pins sticking out ( locost solution) just keep the pressure on the bit with the pins that will engage in the slots and turn gently but firmly.

Worked for me.


A1 - 4/12/08 at 05:44 PM

managed to get them screwed back in earlier with a pair of sturdy needle(ish) nose pliers, undoing the bleed nipple helped make it easier too.. cheers for the help!!