The Testing Issue of Brakes - Updated

Most operators are aware of the need to roller brake test their vehicles and trailers at annual test, but are they or you (if you operate an 'O' licensed fleet), aware of what the Office of the Traffic Commissioners (OTC) actually require?

To get to the root of the requirements of the OTC, we need to unpick the guidance issued in DVSA's Guide to Maintaining Roadworthiness and decipher the language used.? Phrases such as 'strongly advised' and 'normally expected' actually mean this is a 'must' not an option.?

So, let's have a look at the guidance on brake testing and attempt to put it in plain English!

Since April 2023, when the latest version of Guide to Maintaining Roadworthiness dropped, there are now only two accepted methods of brake testing, where Electronic Braking Performance Monitoring System (EBPMS) is not in use, and those are:

• Roller Brake Testing and
• Decelerometer (Tapley Meter) with brake temperature readings.?

There are actually three methods, with the third being a plate tester, but the equipment is not in widespread use, so we’ll concentrate on just the two methods in this post.

Road testing is no longer an appropriate test method for large goods vehicle or passenger carrying vehicle brakes and can only be used for small trailers up to 3.5t with overrun brakes.

Why the change? Well, it has to do with a change of emphasis by DVSA and the OTC.? The question both organisations used to ask was “Do the brakes work?” and we can answer yes or no to that.? Vehicle stops, yes – vehicle doesn’t stop no. ?It’s pass or fail.

HOWEVER (capitalization intended and not excused), the question now being asked is “How well do the brakes work?” and we are now required to provide empirical evidence of the performance of the brakes – read on!

Before I get into the details of what needs to be considered when we carry out a brake performance assessment (it’s not a brake test anymore), operators, transport managers and maintenance providers should go and get a can of spray paint and across one wall in the office or workshop write “Every safety inspection must assess the braking performance of the vehicle or trailer.” This is the primary function of a periodic safety inspection and should be the mantra of everyone concerned with the operation or maintenance of commercial vehicles.

Interestingly, Guide to Maintaining Roadworthiness now includes DVSA’s expectations of what a brake performance assessment should assess, and we are not talking about the end result of putting your foot on the brake pedal.?

No, operators must (that’s a DVSA must – not my must) now satisfy themselves that that the methods used to assess brake performance are sufficient to meet the requirements of Regulation 18 of The Road Vehicle (Construction and Use) Regulations 1986 in that:

Every part of every braking system and of the means of operation thereof fitted to a vehicle shall be maintained in good and efficient working order and be properly adjusted.

Every part of every braking system – that’s a lot of parts to inspect and assess.

Not only that, it is also a requirement that brake test reports are reviewed and understood to ensure the brakes are working correctly. ?

The reason for this?? Deficiencies.? Yes, deficiencies - and I can hear you all saying, “What on earth are deficiencies?”?

Tucked away at the end of the brake performance section is a paragraph that mentions the word deficiencies but does not explain what deficiencies are.? What we do in these circumstances is to look at the dictionary meaning of the word, which in this case gives us variously ‘a lack of or shortage’ and ‘a failing or shortcoming’ or in other words, not having something it should have, or not having enough of that thing.

We need to pay a lot of attention to this ‘last paragraph’ because this is where DVSA explain that a pass is not necessarily a pass.? Yes, you can have a roller brake test report that says ‘Pass’ or ‘Passed’ and it can in fact be a failure – and that is all down to the presence of deficiencies.

At some point I’m expecting DVSA to provide some more guidance, but for now, we certainly know that ‘deficiencies’ relate to:

• Bind (only on service brakes)
• Time lag
• Ovality (only on HGV’s steered axles)
• Imbalance
• Max force

We know this because we have pass parameters, or rather failure points laid down in the HGV inspection manual.? Out of the above list, imbalance is by far the most common deficiency, with an MOT test fail being ‘more than 30%’.? There is a caveat of ‘unless the wheels lock etc’, but we are moving on, we are putting meat onto the bones.

Further, in respect of imbalance, which is a difference in the calculated maximum braking efforts of the wheels on either side of an axle, DVSA add in more guidance and require that where imbalance is over 25% you should investigate why this is and look to adjust your brakes to lower the imbalance.

We can now go back to Regulation 18 of The Road Vehicle (Construction and Use) Regulations 1986 and understand why it has been inserted into the current version of Guide to Maintaining Roadworthiness.? In essence, there is a legal requirement not to have any deficiencies, and to ensure that every part of the braking system is in a good and efficient working order and properly adjusted

The effect of imbalance, by the way, would be to cause the vehicle to pull to one side under heavy braking.

We have tested what I am about to say at public inquiry, so I know that we are on the same page as the traffic commissioners.? With regard to imbalance, anything over 25% will be considered as a fail, and the vehicle will not be considered roadworthy. Operators must then take action to address the issue and have a further measured brake assessment with the vehicle in a laden condition to confirm the brakes are performing satisfactorily.? Only then will the vehicle or trailer be considered as roadworthy.

We also know that the traffic commissioners consider locked wheels to be the lowest form of acceptable performance, and serious questions are always asked of operators to explain why braking efficiency isn’t being restored, why their drivers are being deprived of progressive braking that is proportionate to the amount of pressure or travel of the foot valve, and instead are being given an ‘on – off’ switch.

I haven’t discussed the issue of ‘insufficient load’, which may well be a ‘deficiency’ in the eyes of DVSA and the OTC, I just haven’t been able to put this to the ‘public inquiry’ test yet.? I’m going to say it is. It is a ‘lack of or shortage’ of something after all.

Having discussed the issues behind the guidance on brake performance assessments, we can move on to the methods.? Clearly, roller brake testing is best as it provides information on all of the above deficiencies, and particularly with regard to imbalance as the equipment is able to accurately measure the brake force applied to wheels on either side of the same axle.

Decelerometers (Tapley meters) aren’t as sophisticated and require a temperature check of all brakes to identify whether they are being applied at all, which is done by comparing the brake temperatures with the ambient temperature, and whether a brake is working less efficiently than its pair on the opposite side of the axle (imbalance).

An assessment of imbalance can then be made by calculating the percentage difference between the temperatures on either side of an axle.

It is likely that the proposed implementation of roller brake testing for all brake tests will not go ahead from April 2025, as first planned owing to the lack of equipment exacerbated by increased demand as a result of the new guidance, but I would advise all operators to make the change to roller brake testing now, and establish that relationship with your maintenance provider, before the rush (whenever that might be).

Finally, the last element of the revised guidance is the scheduling of brake performance assessments, because it is no longer acceptable to have your brake performance assessment in the same ISO week, which could have been after the inspection.? The requirement now is to have the brake performance assessment before the inspection, and no sooner than 7-days before.?

Any brake performance assessment carried out, outside of these parameters, can no longer be attributed to the inspection, and the primary requirement that ‘every inspection must assess the performance of the brakes’ will not have been met.?

Further, an acceptable brake performance assessment printout must be given to the maintenance provider, so going back to the issue of deficiencies, operators must now leave sufficient time to have a brake assessment, check the results, rectify any issues and then have a further brake assessment before sending the vehicle for inspection.? Clearly, this will be less of an issue if the maintenance provider has their own roller brake testing equipment, but a lot of toing and froing, if they don't.

In addition, the brake performance assessment printout needs to be signed by the equipment operator.

Why the need for all this activity before the inspection? The answer is critical, but not that obvious and centres on the issue of the signing of the declaration of roadworthiness.? How can a maintenance provider declare a vehicle roadworthy if the brakes have not been assessed, in the case of post inspection brake testing, or if they are not performing in accordance with the legal requirements??

They can’t or shouldn’t – but we continually see inspection sheets pre-dating the brake performance assessments, and where they are carried out in the 7-day period immediately preceding the inspection, there is significant imbalance reported that effectively means the brake assessment has been failed.

To answer the question of whether this is important, we only have to look to the Bath Tipper crash of 9th February 2015 and the substantial terms of imprisonment handed down the director of the operating company and the maintenance provider.

If you are concerned that your maintenance processes are not adequately addressing the current requirements for brake performance testing, call Steve Rounds & Associates Limited on 01543 545050 or email [email protected] ?