Automatic handbrake!!

[Juddian]

For my sins i have been delivering the new picasso (c4 based) and mucho strange handbrake it has too. The handbrake is electrically operated on the rear wheels (laugh but many citroens are not) well you cannot release the brake manually but is designed to progressively release as you take up power, so far so good, you can apply the brake if you wish but it will apply automatically when you switch off..again so far so good. Now call me old fashioned (one of the better names i am called) but i understand the handbrake is also a secondary braking system in the event of brake failure, now my question is how do perform a controlled stop in the event of brake failure with a handbrake thats auto?

 

[television]

For my sins i have been delivering the new picasso (c4 based) and mucho strange handbrake it has too. The handbrake is electrically operated on the rear wheels (laugh but many citroens are not) well you cannot release the brake manually but is designed to progressively release as you take up power, so far so good, you can apply the brake if you wish but it will apply automatically when you switch off..again so far so good. Now call me old fashioned (one of the better names i am called) but i understand the handbrake is also a secondary braking system in the event of brake failure, now my question is how do perform a controlled stop in the event of brake failure with a handbrake thats auto?

Close your eyes and hope for the best.


Malcolm

 

[Juddian]

Funny thing Malcolm but citroen are not alone range rovers are similar, jaguar and renaults are now similar could be this is the new must have, so who is going to make a kit for our 124's that we will not be buying

 

[television]

Hi Juddian, I am not very good at all the latest inovations outside of MB, now you have told me I will make a point of looking, it should not be too hard to do a kit for the 124,129's,140 and early E class.

malcolm

 

[mlc]

For my sins i have been delivering the new picasso (c4 based) and mucho strange handbrake it has too. The handbrake is electrically operated on the rear wheels (laugh but many citroens are not) well you cannot release the brake manually but is designed to progressively release as you take up power, so far so good, you can apply the brake if you wish but it will apply automatically when you switch off..again so far so good. Now call me old fashioned (one of the better names i am called) but i understand the handbrake is also a secondary braking system in the event of brake failure, now my question is how do perform a controlled stop in the event of brake failure with a handbrake thats auto?

This is where I stick my neck out and get shot down by the experts

In the good old (and dangerous) days the handbrake was the secondary brake, but that hasnt been the case for the last 30 years or so. Your footbrake is the service brake, the back up or secondary brake is also the footbrake. Confused, well dual circuit brakes mean that if a single circiut fails you still have at least half the brakes working - which meet the regulations. The handbrake is now simply a parking brake, and interesting means that it can have a lower efficency than required for a hanbrake on earlier cars.

In terms of auto handbrakes the only reservation I would have with an electric brake is that it is fail safe, that is that the electric wizardry holds the brake off at all times rather than applies it, I still personally see the handbrake as the final, last ditch brake.

Mark

 

[television]

This is where I stick my neck out and get shot down by the experts

In the good old (and dangerous) days the handbrake was the secondary brake, but that hasnt been the case for the last 30 years or so. Your footbrake is the service brake, the back up or secondary brake is also the footbrake. Confused, well dual circuit brakes mean that if a single circiut fails you still have at least half the brakes working - which meet the regulations. The handbrake is now simply a parking brake, and interesting means that it can have a lower efficency than required for a hanbrake on earlier cars.

In terms of auto handbrakes the only reservation I would have with an electric brake is that it is fail safe, that is that the electric wizardry holds the brake off at all times rather than applies it, I still personally see the handbrake as the final, last ditch brake.

Mark

Some good point here, re the parking brakes, the size of the shoes in our cars are the same as the rear brakes on a 1960 mini.

Malcolm

 

[Ultymate]

Some of the "automatic" parking brakes create more problems for vehicle recovery on some vehicles it means physically breaking panels to get to the release and once released they cannot be reapplied in some cases:???:

 

[rio678]

I love the parking brake in the Merc 200T estates, just a foot pedal and a release handle.


Yes in event of an emergency you do need a handbrake that is manually controlled, Thats the first thing i would go for if my brakes fail, second to that would be the gearbox into reverse!

 

[television]

I love the parking brake in the Merc 200T estates, just a foot pedal and a release handle.


Yes in event of an emergency you do need a handbrake that is manually controlled, Thats the first thing i would go for if my brakes fail, second to that would be the gearbox into reverse!

So sorry Rio, I would forget your last means, as it would not help you one bit.


Malcolm

 

[rio678]

oh darn, hopefully i will never have to find out )

 

[slim_boy_fat]

Hown many time have you ever had full brake failure on a car you owned?

I think theres the answer...

 

[rio678]

it's not impossible though, it might just well happen......

 

[Juddian]

Hi Slim Boy, true you have to go a long way back to find total brake failure, i had it once only thank Heavens in my sisters Wartburg some 30 odd years ago, luckily the handbrake (funnily enough not electronic) was very powerful, and stopped the car with ease, don't know if any of you remember the Wartburg Knight 2 stroke but it went like a scalded cat. And stank like a polecat!! I am given to understand that the poor quality East German brake fluid would boil up, and yes the brakes returned to normal(ish) when the fluid cooled. The joys of old fashioned cars. My point being though are the manufacturers gatting a little carried away with technology?

 

[izzi613]

While we are on this handbrake issue, I drive a 56 reg Audi A6 2.0TDi Avant for work and while it's badly optioned and therefore in my opinion a dog (manual gearbox and cheapy mono sat nav) it does have a very clever electronic handbrake. A little lever like switch to engage and it automatically disengages when you move away. Works really well surpisingly.

Can anyone tell me have the latest mercs become electronic? The s class still has the pull thingy below the lighting controls....

What I want to know is how one does handbrake turns with these electric ones, same problem with my merc...winters will never be the same!