New Front pads fitted and........

[Jam]

...........now i cannot get the calliper back on the disc. This is of course down to not being able to push the calliper pistons further in to accomodate the new thicker pads. Having read the Haynes manual it does mention a BMW tool that will assist with pushing the pistons into the calliper.

What is the `real world ` method of pushing the calliper pistons back in. Every time i push one in another pushes out (much to the wifes amusement)

Thanks for your time

Jam

 

[bazzjazz]

I have 2 clamps for woodworking and use one to keep one piston in position and the other to squeeze the other piston. This method usually works.

Best of luck,

Barry

 

[littleredrooster]

Make sure the displaced fluid hasn't filled your master cylinder to the point of becoming fluid-locked. This would give the symptoms you describe. DAMHIK!!

 

[boxer]

Put the old pads back in, insert a chisel between the pads then rotate the chisel with a spanner. If it'll fit the shaft of a small hammer is good also.

Russ.

 

[andy malton]

brake pistons

You did take your master cylinder top off didn't you?of course you did.Try spinning/turning them at the same time as pushing them back in.Worked for me,keep an eye on your fluid.Andy

 

[Steptoe]

have you got servo brakes--- because if you have, i've heard of the ABS packing in if pistons forced back in ?. I've not had problems i'm only passing on what i've heard .

 

[Guzzler]

I have 2 clamps for woodworking and use one to keep one piston in position and the other to squeeze the other piston. This method usually works.

Best of luck,

Barry

Must make a note: Be careful when using the C-clamps. The pistons in the caliper are VERY brittle. You can chip the pistons very easily. That is, if you remove the pads and just try to push the pistons back with clamps.

Another method that works well. Remove the pads. Take some tubing and put it on the bleeder nipple. Loosen the bleeder (just like bleeding your brakes). Compress the pisotns, you can use your hands very easily this way.

If you do this properly, you won't need to bleed your brakes. Just top off the master cylinder with fluid.

 

[andrew taylor]

I had a similar problem, solved by simply arseing around and swearing at the thing alot!

 

[CoolCarbon]

I had a similar problem, solved by simply arseing around and swearing at the thing alot!

Yup, me too,

I've got NVQ's, HNC's, MA's, BA's, VD's (Cured!) and Scar in that sort of Problem solving.........

CC

 

[Madmountainman]

Stop being a complete wuss and push em both in at the same time with yer thumbs!!!

 

[Rob Farmer]

Jam,

If you haven't changes the brake fluid yet just suck it out with the Mityvac, push the pistons in and then suck some new fluid through.

 

[Ian Whinnett]

Simple

All of the above could work.

I never take the top off the master cylinder resevoir and I never top up the fliud. Always make sure the fluid level is correct once new pads are fitted and pumped up. You will never have to worry about it again till its time to change the fluid.

The easiest way of pushing both pads (pistons) back at once is to initally remove the slide pin (but not essential) and then using a large screw driverto lever the pads apart whilst the calipers are on the bike.

once the pads are away from the disk use an additional srew driver and a couple of cloths, push both screw drivers between the pads and the disk and be manfull but steady they are meant to be stiff .

The science is that you are trying to puch a large amount of viscous fluid through a small hole into a high friction hose and into a chamber smaller then the volume of the calipers.

Brakes work by hydraulic ratios, a bit like first gear in a gear box. The lever is easy to pull equating to a high legel of pressure at the caliper pistons over a very short distance.

Hope this helps

 

[dave wilcock]

did you clean up the pistons before pushing them back?i i do 1 side at a time remove pads ,pump pistons out (not all the way) use an old toothbrush and brake cleaner.you can buy a tool from halfords for a tenner or so that will push all four at the same time (made for cars but fits).