Rear brake... pushing piston back?

[TVR Beaver]

Having eventualy got some discs i deem as usable, i've spent 10 mins this AM trying to push the piston back?... i've tried G-claming it to move it back... and i've had a peg spanner in there to turn it clockwise and screw it back... neither appear to work?... it just stays there or just goes round... but does not go back?...
I know you can gat a tool for this... how does it work?.. does it allow you to screw it clockwaise and push it back at the same time?..
If anyone knows it would be handy as I thought just turning it would do the job??.

[Goaty Bill]

Pardon my ignorance as I have always had mine done for me, but assuming it's original brakes, I think there is a wind back tool for this?
Talked myself into doing a set of Audi brakes a while back, and managed to locate one for about £20.
For Ford brakes it's got to be easier to find one...

Here's a guy doing the unofficial way, but there are a few links to the side clicky that might be more useful.

[TVR Beaver]

Thanks for that.. I've managed to get them going with my peg spanner (must have been stuck and turning the cylinder or something).. all back in now and caliper number 1 back on

was wondering about the allen cap heads that hold the calipers on.. has anyone replaced these... would be much easier with hex heads as you can't get a normal alen key into the buggers (I have a cut down one but still not easy)... high tensile hex would do i assume

[Hedgehopper]

In place of a proper wind-back tool you can use the peg spanner from an angle grinder.

[Ozstyle]

Hi,

I had the same problem when changing my rear brake pads.
I was able to push the piston back in by turning and pushing as per the procedure, but it got to a point were it would not go any further. The piston would keep turning but I could not get it to fully retract into the caliper body. The fix was to winde the piston back out and try again, it worked this time the piston retracted as far as needed to get the new pads in.
I used a pair of long nose pliers as the winde out/in tool.

hope that helps.

Ozstyle

[TVR Beaver]

yes.. thanks... TBH thats how I got them to move yesterday... wind them out and back in... also a G clamp does push them in and will rotate them a bit as it goes... not sure how thee set up works?.. is there a screw thread in there somewhere???

[spend]

TVR Beaver said:

yes.. thanks... TBH thats how I got them to move yesterday... wind them out and back in... also a G clamp does push them in and will rotate them a bit as it goes... not sure how thee set up works?.. is there a screw thread in there somewhere???

Yes thats the handbrake adjuster...

You need to slacken off the cable adjuster fully, and if seized work the adjuster lever a bit as you move the piston. Judging by the problems folks have with handbrake adjustment I would advise working the piston in out several times and ensuring that the adjuster clicks in as you use pedal pressure + handbrake lever (with old pads) before installing new pads & resetting the handbrake.

[TVR Beaver]

spend said:

Yes thats the handbrake adjuster...

You need to slacken off the cable adjuster fully, and if seized work the adjuster lever a bit as you move the piston. Judging by the problems folks have with handbrake adjustment I would advise working the piston in out several times and ensuring that the adjuster clicks in as you use pedal pressure + handbrake lever (with old pads) before installing new pads & resetting the handbrake.

so if it all goes back and the pads are in and on the disc is it job done?... Or could you have the cylinder forward and the srew bit too far back etc??...

I don't see how releasing the adjuster helps as it only work a ratchet type thing once its all together??

[Quinny]

I used to wind back the piston, with a small amount of pressure from a g clamp....

One thing to check though....on the rear pads is a small raised peg.....make sure that this peg on the pad is located in one of the slots on the piston.... You may have to line up the slot to the right position to accept the peg

Once your happy this is ok, refit the caliper, and press the brake pedal to push the pads back up to the disc

[TVR Beaver]

yes.. done that... so I guess back is back and you can't go wrong so long as it fit over the disc.. basicaly it sorts itself out once the brakes are pushed..

still interested in how it workes however... will go see if I can find a pic on Google

[Quinny]

It's quite clever, it's basically a big screw inside the caliper.... As you pull the handbrake, it twists the screw, and pushes the piston out....the screw is spring loaded, so once the handbrake is released, the spring pulls the piston back... Only by a mm or so, but just enough...

Its one of the things I've never understood, when people have said TVR handbrakes are rubbish, and not to be trusted...

The fact is, if they're adjusted correctly, and everything is working as it should, it's just as good as any other handbrake

[TVR Beaver]

here's an exploded pic of the unit?.. still can't quite make out whats going on?... obviously there is a main piston.. and I assume a inner one that screws out when the hand brake is pulled... so you are only screwing it in a turn or two.. if you keep on turning you are just spinning the piston... and that part will just push back anyway?...
will have to have a closer look?.. didn't you do a vid on this one before

[Quinny]

Don't think I did a vid..... Just a bit of a how to thread..

[phazed]

Quinny said:

The fact is, if they're adjusted correctly, and everything is working as it should, it's just as good as any other handbrake

You still won't be able to do handbrake turns

[V8 GRF]

Quinny said:

The fact is, if they're adjusted correctly, and everything is working as it should, it's just as good as any other handbrake

I agree, the issue I guess is due to the handbrake being mounted higher than in it's original installation so you can't apply as much leverage as you're not pulling up on the lever with a straight arm.

phazed said:

You still won't be able to do handbrake turns

Yes you can