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MOT Sections
Brakes
MOT checks for motorcycle brakes are divided into three sections. Please click on a link below to skip to the section of interest.
brake controls :: brake systems :: brake performance
Brake Controls
- Motorbike breaking systems must have two methods of operation fitted and functioning
- All controls, mountings and fastenings must be secure and in good repair
- All pivots must be within reasonable levels of wear tolerance
- All controls must be easy to apply and have adequate reserve travel on application
- Hydraulic systems must not creep* under load or feel spongy when applied
*creep: Fully depress you break lever and hold it firm. If, over time, its resistance grows less and it slowly allows you to add more and more pressure, this is called creep. It most likely means you have a leak somewhere in the hydraulic system of that brake.
Modifications
The VOSA handbook says that an MOT certificate should be refused if any ‘deliberate modification’ has significantly reduced the original strength of a load bearing member or it’s supporting structure.
Pre-1927 Motorcycles
Motorcycles which were first registered before 1st January 1927 only need to have a braking system which works on one wheel, not both.
Brake Systems
- All security or locking devices such as split pins, lock nuts etc must be present and secure
- Standard brake pads or linings must be at least 1.5mm proud of their backing plates
- Sintered brake pads or linings must be at least 1mm proud of their backing plates
- Hydraulic reservoirs must be securely mounted, capped and sealed
- Hydraulic reservoirs must have sufficient fluid in them
Other reasons for brake systems failing the motorcycle MOT
- Excessively worn, corroded, cracked or in any other way damaged cables, levers, rods and linkages
- Insecure or cracked drums or discs and missing securing bolts
- Too much free play on levers through wear or poor adjustment
- Contamination of brake pads by oil or grease
- Insecure backing plates, reaction brackets or calipers
- Leaking master cylinders or brake pipes/hoses
- Brake pipes which can be easily fouled or trapped by other moving parts of the motorcycle
- Inadequately supported rigid pipes/hoses
- Excessively chafed, twisted or kinked brake pipes/hoses
- Disc scoring, pitting or wear
- Excessive brake disc run out* or distortion
*run out: whilst the bike is moving very lightly apply each of the brakes in turn and slowly increase pressure. If you can feel a slight pulsing whilst doing this, that is run out. It is caused by warped or uneven wear in your motorbike’s discs.
note on brake hoses: damage to the protective sleeves of brake hoses will not necessarily fail the bike MOT provided the pipe or hose to which it is attached is not damaged. Cracking or chafing must be severe enough to expose the hose reinforcement to be considered a fail.
note on movement of discs: many discs fitted to modern sports motorcycles are ‘fully floating’ which means they are designed to have a certain degree of movement. If in doubt consult a qualified motorcycle MOT test technician, do not assume that some movement in your disk is an MOT fail. The tester may, at his discretion, take your bike for a brief road test.
Brake Performance
Reasons for your motorbike’s brake performance failing the MOT
- Sticking or binding brakes
- Severe grab or judder
- Braking effort which is inconsistent with the amount or pressure applied at the lever
- Excessive fluctuation of brake effort when steady pressure us applied
- At least one brake must achieve 30% efficiency* with the other at least 25%
*efficiency is calculated by the motorcycle MOT computer system using this formula:
Efficiency (%) = (Retarding Force ÷ Weight) x 100
The total retarding force is measured using either a VOSA approved brake tester and Weight is the combined weight of the motorbike plus motorcycle MOT test technician. In the case of linked or dual braking systems the retarding force is the total from both wheels when operated by the dual control only.
I have a yamaha neos and want to convert the rear brake to disc. There is not enough room on the handlebars to mount the master cylinder for the rear brake on the left side. Years ago Vespa and other makes of scooter’s had the rear brake work on the floor as a push pedal. Is there any law that says the rear brake cannot be foot operated on a scooter for this conversion ?
Wow. Depends how much you change the structure of the vehicle. Too much and it would come under Type Approval rather than just an MOT.. But no, there is no law preventing you from doing this. Many vehicles are modified in a similar manner for disabled riders etc.
Do you have to have a front brake light switch on all bikes.
No you don’t. If the bike was manufactured with only one switch it is OK.
It looks as though my front brake lines cross over up to the brake reservoir, they work fine but is this ok to pass m o t?
Hi Steve,
It will be fine as long as they aren’t catching on anything or get in the way when the forks or steering is operated.
All the best,
FTMC
My daughters piaggio zip has failed because of inadequate reserve travel of near side lever, for the life of me I can’t get it through adjustment of the rear drum adjuster, how can I achieve it so it passes thanks
Hi there,
You could try putting new brake shoes in or try to adjust it by moving the brake pivot arm one notch on the spline.
Hope this helps
FMTC
Hi just bought a bike brakes work fine but there’s no sight glass in the front brake resavoir just been sealed is this ok for mot as you obviously can’t see the brake fluid level . Thanks
An MOT tester is not allowed to remove things and cannot fail based on assumption. Only the correct operation of the brakes will be tested.
Should the tester ride my bike outside the test centre during the test if he is not using a decelerometer fro the brake testing
If he feels it necessary, then yes. It is at the testers discretion.
Is it legal in the U.K. to drive with only a back brake on a motorcycle
No, you need both front and back brakes for the bike to be legal.
My motorcycle is a custom bike and has no brake light switch from the front brake but does from the rear brake, is this a reason for a mot failure? The bike is a 1980. thanks
No, it’s not a problem as the bike was originally built before 1st April 1986 🙂
I have a Suzuki Burgman 400. This is fitted with a ‘parking’ brake.
The tester failed the bike saying this was not working. Saying the bike required new pads and caliper. Is this a testable item? I argued that it was not. I made a minor adjustment to the locknut and screw which gave some effect to the ‘handbrake’ and they reluctantly passed the bike. I won’t use them again.
Joe Mitchell
If the handbrake was failing because the bike needs new pads and caliper then we would fail it too! But it wouldn’t be the handbrake that failed it as, you’re correct, that isn’t a testable item. Bring it to us next time 😉
I have a 1989 BMW K100lt and have been told that ABS on these machines was an optional and additional safety measure and is not subject to MOT can you advise please
If ABS wasn’t fitted from new then it doesn’t matter. If it was then brakes simply need to operate as any other hydraulic brake system would.
My front disc have seen better days, there is some pitting and ridges. The brakes still work very well, would this be an MOT failure?
We would have to physically see the disk to assess the extent of the pitting and measure the thickness but ridges are usually advisory only. All brakes are tested on a roller brake tester before we can say 100% whether they pass or fail though.
Hi. I have bought a 1991 import Kawasaki intruder. It has no front side light fitted and no provision to fit one. Is this an m.o.t fail as it came from the factory like it? Thanks.
That’s quite an awkward one. If the lights come on automatically like all UK spec bikes from 2003 onwards then a sidelight is usually fitted but is only an advisory, not a fail, if it’s not working. However if the lights are still on a manual switch then a side light is required and it must be white. A cheap LED stick-on from Ebay etc placed under the main headlight would do the job perfectly well.
My GSXR 600 has 4 settings on the front brake lever, I had recently changed the pads but did not change the fluid and was running the bike on setting 4 (the softest) with no issues. However, it failed the MOT as the lever on setting 4 reached all the way to grip. I have changed the fuild and settings 1-3 all leave a min of a finger width, but setting 4 still reaches the bar, any ideas if this will pass the retest? if not, what do I do?
For the purposes of the M.O.T i would set it to the number 1 position and this would then pass as adjusting the lever is not something we can do on an M.O.T.. However a GSXR 600 should have almost no travel at all so as a proffesional i would recommend you get the issue sorted regardless of M.O.T pass. If the lines are NOT steel braided and have never been changed in the life of the bike then this can cause alot of flex and similar problems to what you are getting, most manufacturers recommend lines get changed every 2-3 years. Another common issue is the Brake caliper seals, without going into too much technical detail, corroded calipers and old seals can cause this problem and finally a slighlty less common problem is the Master cylinder seal failing. Being as the brakes are one of the most important safety features on the bike i would recommend you replace all these items. Hope this helps FTMC
Please can you help.
My 1972 Suzuki TS125 has cable operated drum brakes. The rear works from foot pedal as normal. The single handlebar brake lever operates both front and rear brake. The lever has twin adjusters for each brake cable. This has been done due to my foot is slightly disabled and cannot always fully depress brake lever. Will my bike pass MOT ? thanks.
Hi there, lots of motorcycles have combined braking systems, some hondas have a similar system fitted to them. Providing the modification has been done correctly then it won’t cause a failure. hope this helps. FTMC