A friend has just put his S type Jag through an MOT and whilst it was on the brake test rolling road, a brake pipe suddenly burst during the test and it lost all braking, with the brake pedal going all the way to the floor.
He wondered if he could use it's electric handbrake if it ever happened in real life. I didnt know.

The electric handbrake (EHB) on my 2014 FL2 appears to function as an on/off device .
I am guessing that there is an inhibitor to stop it working at speed, as sudden locking of the rear wheels would only add to the emergency.

So the question is; can the FL2's EHB be used in an emergency for reduce the vehicle's speed in a controlled manner should there be a total loss of normal hydraulic braking ? Jules

Hi
Yes the EBS does work as an emergency brake. If you hold the switch in the up position whilst driving it will apply the brake in increments to safely bring you to a stop. If you let go of the switch it will also let go of all braking.
I believe it says this in the handbook but I know it works as i some what accidentally tried it. MY06 FL1 TD4 2 door red (gone)
MY07 FL2 SE TD4 black (gone)
MY13 FL2 GS TD4 Santorini black

You're right - it is mentioned in the manual - it not highlighted and I missed it when having a very quick look. Jules

 MY06 FL1 TD4 2 door red (gone)
MY07 FL2 SE TD4 black (gone)
MY13 FL2 GS TD4 Santorini black

Hi,
as DW says

its like doing an emergency stop but using the switch rather than your foot

we did it in a FFRR on an experience day while out on a road section

all done safely and the instructor said he had to do it once as a driver was taken ill at the wheel and they needed to pull up quickly

As with most things trying them in a Safe Environment is always worth while so you know what is going to happen when you need to use it, how many people have done an emergency stop (with the footbrake ) to see how the abs feels,
its not very intrusive these days but a few years back abs it was

 .
my first ever FL2 and I did keep it longer than most other cars!
But its now gone way up Norf

jules wrote:

A friend has just put his S type Jag through an MOT and whilst it was on the brake test rolling road, a brake pipe suddenly burst during the test and it lost all braking, with the brake pedal going all the way to the floor.
He wondered if he could use it's electric handbrake if it ever happened in real life. I didnt know.

The electric handbrake (EHB) on my 2014 FL2 appears to function as an on/off device .
I am guessing that there is an inhibitor to stop it working at speed, as sudden locking of the rear wheels would only add to the emergency.

So the question is; can the FL2's EHB be used in an emergency for reduce the vehicle's speed in a controlled manner should there be a total loss of normal hydraulic braking ?

Our first DS had electric hand brake, we took it for the MOT and the test station only had a two wheel rolling road so we took the car on a side road with a pendulum type tester. The idea is when you brake the pendulum swings forward proportional to braking force.
We tested the the road brakes at 20MPH and they were fine, very fine. Next the parking brake, I advised the tester to grab the dashboard before the test, boy o boy does pulling the handbrake stop the car. Now you and I know that grabbing the handbrake while moving puts the ABS into action on all 4 wheels, he wasn't expecting this, first time he's had the "handbrake" out perform the road brakes.
The 'handbrake while moving' function has no mechanical sympathy, whereas you on the brake pedal do hopefully.

Not sure if the ABS works as such while pulling the handbrake as there were 4 tyre marks on the road pointing out that all 4 brakes were working and at the same time. Good enough for me. Tangiers Orange - gone, missing her
Replaced by Ewok what a mistake - now a happy Disco Sport owner

Quote from JLR
If the EPB is operated when the vehicle's speed is less than 2 mph (3 km/h), the vehicle will be brought to an abrupt stop. The stop lamps will not be illuminated.

CAUTION
Driving the vehicle with the EPB applied or repeated use of the EPB to slow the vehicle, may cause serious damage to the brake system.

In an emergency, with the vehicle traveling at more than 2 mph (3 km/h), pulling on the EPB switch and holding, gives a controlled reduction in the speed, as long as the accelerator pedal is released. The brake warning lamp will illuminate, accompanied by a warning tone and a warning message in the Message center. The stop lamps will illuminate.

If the vehicle is stationary with the EPB applied and the gearbox engaged in Drive (D) or Reverse (R), pressing the accelerator will release the EPB and allow the vehicle to move off.

This leaves me with some questions

Taking the EPB normally works on only 2 wheels when stationary, is the 'emergency' function programmed differently to work on complete braking system, and if so, does it also work with ABS, and is there any stability functions employed such as 'anti-yaw' or 'anti-roll'? It does say a controlled reduction in the speed. FL2 XS SD4 Auto 2010 2012-2017 (21k - 91k miles) (MY2011)
FL2 Metropolis SD4 Auto 2014 2017- (16k - 76k+ miles) (MY2015)

Can't say about the FL2 as mine was 2008 with traditional handbrake.

But the DS at speed (haven't tried above 20mph) does not bring you to a controlled stop, it's a very hard stop and will leave 4 skid marks on the road, implying that although it utilises the ABS system it doesn't pulse the brakes to prevent wheel lock-up.
The FL2 system could be more sophisticated, anti-roll or anti-yaw would be a good idea in a panic situation ie brakes have failed and you need to stop NOW, not a situation I would want to attempt to test.

I can tell you for sure that the older system with a lever and shoes is nigh on bloody useless when a brake hose fails at high speed on the motorway and a muppet cuts you up. Anyone who says that split brake systems save lives are talking through their , press pedal once and NOTHING happens, your foot goes nearly to the floor, you do it again and you empty the reservoir, still nothing, pull hard on the handbrake and prey. You now have 2 tonnes at 70mph and need to start looking for an exit, at which point you have got to hope you are not on a "Smart" motorway and there is a traditional hard shoulder. Tangiers Orange - gone, missing her
Replaced by Ewok what a mistake - now a happy Disco Sport owner

Nodge68 wrote:

jules wrote:

?

all the brakes being applied at full power, which can cause week or rusty pipes to fail.
The ABS modulator will apply the brakes extremely hard, which is why weak pipes can fail.

It works to give an Emergency stop the same as if you hit the brake pedal so if a pipe was going to fail it would via brake pedal as well

ABS should work the same as well, its a switch that tells the brake system "Full power please we need to stop asap" wheels should not be locking up any different to brake pedal being used

 .
my first ever FL2 and I did keep it longer than most other cars!
But its now gone way up Norf