Rear disc conversion - how does the Sierra handbrake work?

[Danish]

I'm just about finished a rear-disc conversion for my Mk3 Cortina.

 

This morning I fitted the handbrake cable to the callipers - they're the standard Sierra ones, with a lever to pull for the handbrake:

 

 

But I'm not getting any braking from the hand-brake, despite having the cable tensioned, and I can see the lever is moving when the hand brake is on.

 

I'm wondering does the handbrake mechanism have some sort of mechanical linkage inside the calliper, or is it hydraulic?

 

Or to put it another way, will I need to put in some brake fluid before it works, or do I just need to tighten the cable more?

[Vista]

I remember having this issue with mine, the Sierra caliper pistons need to be wound out to get the brake adjustment right on first fitting. From memory you have to have the hydraulic system bled and apply the foot brake so the pads are tight on the discs and then bring up the handbrake to adjust the mechanism.

 

The piston is pushed out by fluid pressure and the handbrake relies on a thread inside the piston that turns as you apply the handbrake this also accounts for the auto adjustment. There's also 4 grooves in the piston and one of them needs to line up with the little pin that sticks out of the middle of the pad, this pin / groove arrangement stops the piston rotating back in once it's set up.

[RodO]

Putting your foot on the brake, and pulling the handbrake on and off several times until the adjustment comes up should see things working properly.

 

It may take a bit more than you expect though.

 

Cheers,

Rod.

[mk2dk]

Hi Danish.

An old mechanic once told me to leave the handbrake cable un-adjusted, then drive the car for 10-15 miles using the brakes in a nomal way, no hard braking and no handbrake use. After the pads and hydraulics has settled, adjust the cable and the handbrake will be fine.

mk2dk

[khanlad]

If i remember right bleed brakes with cables slack then adjust cables after. The cable attaches to the arm thing that when it turns pushes like a tic tac thing against the inside of the piston and gives your hand brake. Obviously this is all very techincal talk which you may not have the faintest idea of what im on about...... but i do!

[colr6]

Are You SURE about that ??

[khanlad]

Pretty sure?

[colr6]

The seed of doubt has been sown

[khanlad]

It is how it works just not very well explained without doing hand signs and stuff! Instigator of trouble!

[Danish]

Thanks for the replies everyone - I haven't bled the brakes yet as I'm waiting for longer banjo bolts to arrive. Once that's done I'll get the foot brake working before worrying about the hand brake.