MOT handbrake test

Just pondering... How does an MOT tester test a Disco Handbrake?

When i bought my disco it had already been tested and failed. One of the failures was

"Handbrake efficiency below standard: 14%"

just wondering how they test is, I've pulled the HB on and revved the car in drive (for i have an auto) and there is no movement anywhere....

When they tested mine the other week the tester drove along and pulled it up at about 5mph.

I thought it was a bit dodgey but he had done the landy before like it too.

JdMilner said:

When they tested mine the other week the tester drove along and pulled it up at about 5mph.

I thought it was a bit dodgey but he had done the landy before like it too.

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i would have smacked if face, if the hand brake failed because he used it incorrectly how could he mark it as a fail

Daft fooker probably had it on rollers. Go back and ask him to demonstrate his test procedure. It should be parked on a slight incline and the handbrake applied.

TESTING TRANSMISSION (PROP SHAFT) HANDBRAKES
Carry out the following procedure:
• The system is set to default to the brake mode that tests the handbrake on individual
wheels therefore select the brake test mode that tests both wheels together.
• Keep the handbrake ratchet disengaged for as long as the brake is applied.
• Apply the brake slowly and progressively without causing transmission snatch.
Note:
A transmission handbrake fitted to a permanent four-wheel drive vehicle can not be tested
using the brake roller tester.

http://www.dvlni.gov.uk/Freedom of ...cle Inspection Manual/Brake - Performance.pdf

dyte said:

i would have smacked if face, if the hand brake failed because he used it incorrectly how could he mark it as a fail

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That is the correct method if using a decelerometer thingymawotsit.

BRAKE PERFORMANCE (DECELEROMETER TEST)
INFORMATION
AREA USED FOR DECELEROMETER BRAKE TESTING
The requirement for a steady speed during a brake test by decelerometer means that the
vehicle must always be driven on an area which:
a. Has a good surface,
b. Is suitable for brake tests when dry or wet,
c. Has a minimum of traffic.
TESTING TRANSMISSION HANDBRAKES
When using a decelerometer to test a transmission handbrake, keep the ratchet
disengaged for as long as the brake is applied. Take the efficiency reading without the
occurrence of transmission snatch or judder.
VEHICLES WHICH JUST PASS
With some vehicles, the required brake efficiency is just obtained or just exceeded, but the
examiner knows that a higher performance figure is normally obtained for the type of
vehicle. Although the vehicle has passed the brake performance test, the examiner should
advise the vehicle presenter that the braking system appears to need adjustment or repair.
METHOD OF INSPECTION
DECELEROMETER TEST
1. If the vehicle is of a type which cannot be tested on a roller brake tester:
• Set up the decelerometer in the vehicle in accordance with the equipment
manufacturer’s instructions,
• Drive the vehicle on a level surface at a steady speed of approximately 20 mph
(32 kph) and note the brake efficiency recorded when applying only
i. the service brake,
ii. the parking brake,
iii. secondary brake if approperate,
2. While the vehicle is decelerating under the action of the service brake, note if the
steering wheel tends to pull or the vehicle tends to swerve.
3. while the vehicle is decelerating under the action of the parking brake note if the
vehicle tends to swerve excessively.
4. If half the number of wheels on a brake system lockup then it is assumed that the
efficiency requirements are met.
REASON FOR REJECTION
1. The service brake efficiency recorded on the decelerometer does not meet the
requirements specified in the Brake Efficiency Table.
2. The parking brake efficiency recorded on the decelerometer does not meet the
requirements specified in the Brake Efficiency Table
3. When the service brake is applied:
a. There is a service grab or judder, or
b. There is a severe pull one way on the steering wheel, and/or
c. The vehicle swerves appreciably
4. When the parking brake is applied the vehicle swerves excessively from a straight
line.

You do it with an accelerometer to measure the g force if you can't use rollers. Which means road testing which you wouldn't normally do on an mot

when mine has ever been tested the tester just pulls handbrake and lets clutch out slowly if it stalls its a pass

Yeah like that

dyte said:

when mine has ever been tested the tester just pulls handbrake and lets clutch out slowly if it stalls its a pass

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It works, but it's not the official way

Diesel Do said:

It works, but it's not the official way

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no but the taply deceleration meter is not really accurate either is it lol

As said already its not roller tested, it does nothing on the rollers as the prop isnt turning (for perm 4wd the rollers go opposite ways to test the service brake)

It is down to the examiner really, if its sensible it will pass, some dont realise its a prop brake and so give it a 0% reading but a good garage should know

dyte said:

no but the taply deceleration meter is not really accurate either is it lol

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Very true. It is really a case of if it works it works but they want numbers to back it up.

Diesel Do said:

Very true. It is really a case of if it works it works but they want numbers to back it up.

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they just don't test them here lol and they wont fail on rust here unless its super dangerous test every two years aswell

it wasn't done on rollers, and you can't stall an auto lol.

I took it to another tester who knows about landrovers and doesn't use a decelerometer, he said it's not great, but it works. Said to take the drum off and check for oil on the shoes.

decelerometer is the way it should be done, but i think most places will pass it so long as it holds the vehicle weight, i know both mine were done with the decelerometer and all was kool