Handbrake Question

[smithsc]

Hi Guys,

Since the weather has been bitterly cold i've noticed every morning my handbrake has been seized on.

Last night i was driving home and tried to put the handbrake on (stuck in traffic going up a teep hill) and the handbrake wouldn't hold. On my previous car Volvo T5 it had handbrake shoes inside the rear discs and when this happened they needed replacing.

How does the leon handbrake work as i think it might have just worn down and need replacing

 

[Muttley]

The handbrake actuates the rear caliper pistons mechanically. Bellcranks on the rear calipers transmit the lever action to rods that attach to the caliper pistons by an internal thread. The pistons automatically adjust by climbing up the screw thread a little bit every time you use the brake pedal.

The weak points are the bellcranks and the rods themselves. Corrosion gets to them and they seize up. The cables can stick, but that's unusual.

If the pads wear down too much, the pistons can come off the end of the rods, effectively running out of adjustment. Pads have to be seriously neglected for that to happen though.

Separate shoes on a little drum, or even a separate mechanical caliper, are much better ideas, but more costly.

 

[Muttley]

I've had difficulty in the past finding diagrams that show the handbrake mechanism in the caliper, as it isn't something that gets serviced; dealers just replace the whole caliper. The page below is for Lexus, but shows how the handbrakes on the rear disks of a Leon work from a few pages down.

http://www.autoshop101.com/forms/brake06.pdf

The crank on the caliper is exposed to water, road dirt and salt and is the usual place for corrosion and seizure to strike first.

You need to find out the size of the problem Chock the front wheels so they can't move either way and put the rear end up on axle stands so you can rotate the rear wheels.

Check the pads on both sides to make sure there is plenty of material left - a couple of millimetres or so. If the pads are too worn there is a risk that the adjustment mechanism has hit its limit.

Handbrake off, spin one wheel, put the handbrake on and see if it stops and how much grip the handbrake has. Then do the other side. Easier if you get a mate to do the handbrake bit.

With the handbrake off the wheel should spin freely - if not, the handbrake is probably seized on.

Application of the handbrake should stop the wheel straight away and you shouldn't be able to turn it at all, even with the wheelbrace.

If you've identified that one side has seized, take the rear wheel off and watch as the handbrake is actuated. I'd expect the lever on the caliper will move only a little or not at all. That would indicate a seized handbrake mechanism on the caliper. If both sides move but you still have the pads seizing on, then either a piston is stuck in the caliper or one has run off the end of the adjuster. Or something else is wrong. Diagnosis at a distance is a bit difficult.