Electronic handbrakes - can you do this?

[R11ysf]

So the other morning I had total brake failure on my golf and the pedal went to the floor. I had to still move it about 30 yards so i drove it there stopping it on its handbrake.

This got me thinking how would you do this with an electronic handbrake? Is it even possible or does 2 or 4 circuit brake systems mean total brake failure doesn't happen anymore?

[HustleRussell]

Pretty much everything has been dual circuit for decades now, so sudden total brake failures are not common.

[anonymous-user]

R11ysf said:

So the other morning I had total brake failure on my golf and the pedal went to the floor. I had to still move it about 30 yards so i drove it there stopping it on its handbrake.

This got me thinking how would you do this with an electronic handbrake? Is it even possible or does 2 or 4 circuit brake systems mean total brake failure doesn't happen anymore?

Knowing how the minds of manufacturers work it would probably have some failsafe mode, jam the handbrake on then ask you to take it to the local dealer and hand over your wallet

[jamieduff1981]

It works on the Jaguar system. If you pull up the switch on the move it bleeps at you but keep it held beyond the bleeps and it applies the brakes. Press the switch down again with foot on the brake pedal or reapply accelerator and it releases as per normal operating.

The implementation is an electric screwjack pulling steel cables which actuate the rear caliper pistons via lever operated cams - much like other park brake mechanisms, so loss of fluid in the brake circuits is an irrelevance. The only difference is that in place of a hand lever is a switch and an electric screwjack.

Edited by jamieduff1981 on Monday 10th February 13:26

[anonymous-user]

Most modern electronic handbrakes will gently apply the service brakes to progressively slow the car if operated at any significant vehicle speed. (ie if you pull on the handbrake button when driving along, without any accelerator input)

[Ozzie Osmond]

The Porsche electronic parking brake is utter, utter cack.

• Hill hold which can't detect most hills
• Jerky operation
• Slow to release, can stall the engine
• Operating switch out of driver's reach

[wolf1]

HustleRussell said:

Pretty much everything has been dual circuit for decades now, so sudden total brake failures are not common.

The dual circuit only works when one of the seals in the master cylinder fails. Any loss of brake fluid at all post master cylinder will end up after a couple of pumps or so of the brake pedal in total failure.

The activation of the handbrake is as the poster above mentioned, to apply the button etc for the parking brake in the normal way but to keep it held where upon the parking brake will function (makes a fair but of noise in the process)

[McWigglebum4th]

wolf1 said:

The dual circuit only works when one of the seals in the master cylinder fails. Any loss of brake fluid at all post master cylinder will end up after a couple of pumps or so of the brake pedal in total failure.

Nope

if you look you will see the resvoir has two outlets into the master cylinder so when it get belows a certain level you have one working brake ciruit

[R11ysf]

Max_Torque said:

Most modern electronic handbrakes will gently apply the service brakes to progressively slow the car if operated at any significant vehicle speed. (ie if you pull on the handbrake button when driving along, without any accelerator input)

So is this the end of the age old hand-brake turn?????

[AJB]

McWigglebum4th said:

wolf1 said:

The dual circuit only works when one of the seals in the master cylinder fails. Any loss of brake fluid at all post master cylinder will end up after a couple of pumps or so of the brake pedal in total failure.

Nope

if you look you will see the resvoir has two outlets into the master cylinder so when it get belows a certain level you have one working brake ciruit

In fact, one of the seals in the master cylinder failing (the one on the piston attached to the pedal), is about the only way you could get total brake failure with a single fault in a dual circuit car.

[Newro]

jamieduff1981 said:

It works on the Jaguar system. If you pull up the switch on the move it bleeps at you but keep it held beyond the bleeps and it applies the brakes. Press the switch down again with foot on the brake pedal or reapply accelerator and it releases as per normal operating.

The implementation is an electric screwjack pulling steel cables which actuate the rear caliper pistons via lever operated cams - much like other park brake mechanisms, so loss of fluid in the brake circuits is an irrelevance. The only difference is that in place of a hand lever is a switch and an electric screwjack.

Edited by jamieduff1981 on Monday 10th February 13:26

Ah, thanks, I was actually wondering about that.

I still wonder if operating it at any reasonable speed will cause some damage beyond normal wear and tear or none?
Also, there is no feel for it, so while I know that the system will apply the rear breaks in a 'controlled' manner, I am still worried about this on demanding road conditions, like snow and ice.

I have very mixed feeling about electronic parking breaks, but for better or worse, it looks like they are here to stay. Not even the F-Type has an old fashioned hand break any more!

[john2443]

I can't see any advantage to them except
a) for the manufacturers they must be cheaper
b) they take up less space in the passenger compartment, but that's so marginal as to be not really worth considering.

If I was moving a car like you want to I think I'd keep my hand on the ignition key (bks, does it have one of those, or a stupid button?) and be ready to turn the engine off to stop it, I wouldn't be very confident getting the elec hand brake to stop it.

[Hooli]

Newro said:

jamieduff1981 said:

It works on the Jaguar system. If you pull up the switch on the move it bleeps at you but keep it held beyond the bleeps and it applies the brakes. Press the switch down again with foot on the brake pedal or reapply accelerator and it releases as per normal operating.

The implementation is an electric screwjack pulling steel cables which actuate the rear caliper pistons via lever operated cams - much like other park brake mechanisms, so loss of fluid in the brake circuits is an irrelevance. The only difference is that in place of a hand lever is a switch and an electric screwjack.

Ah, thanks, I was actually wondering about that.

I still wonder if operating it at any reasonable speed will cause some damage beyond normal wear and tear or none?
Also, there is no feel for it, so while I know that the system will apply the rear breaks in a 'controlled' manner, I am still worried about this on demanding road conditions, like snow and ice.

I have very mixed feeling about electronic parking breaks, but for better or worse, it looks like they are here to stay. Not even the F-Type has an old fashioned hand break any more!

They are brakes

Operated from enough speed it'll probably melt the friction material off the handbrake shoes, if it's the normal way I've seen things done with a tiny drum inside the disc.

[Moonhawk]

On our Volvo XC60 - the user manual states that in the event of a main brake failure - the electronic handbrake can be used as an emergency brake by depressing and holding the button.