Hi there,
I've just registered to ask this about my MOT pass this morning.

I've just seen the brake efficiency , and it looks very low. They didn't mention it at the time, only when i looked at the document at home and read it now i am concerned.

Test result - Pass (wheel locks)

obviously, the car wouldn't of passed mot if this was super bad, but it looks iffy to me!
New brakes needed?

advisory information:
001 - Exhaust has a minor leak of exhaust gases front [7.1.2]
002 - Anti-roll bar linkage has slight play in a ball joint offside front (drop link) 2.4.G.2


Kind regards,
Thomas.

Those figures looked very low, so I've just hooked out my last one.
My front efficiency was 83% and rear 79%. Parking brake 19%. Parking brake is always low, but it is intended to hold the car, not stop it. My sheet shows a lower limit of 16%, so expectations are low.

Your service brake figures are poor. Do you find stopping hard work? My sheet also shows the pedal pressure needed to achieve this at 235kgf, which seems high, but I don't know how this is being measured.

Your front imbalance is normal, but the rear is higher than ideal.

I think the reason you got a pass is that despite the low readings, it was capable of locking the wheels. However, this looks like a project for you, as soon as possible.

Front brakes could be poor pads, even if they look OK, they might be cheap ones. Get a good brand name. Pagid from Euro Car Parts are fine, they are part of TMD Friction, a very big name in brakes. Might also be tight or sticking calipers, or poor discs, with wear or corrosion giving less friction surface. It all needs looking at and fix whatever needs fixing.
Rear brakes, as above could be poor friction material. I'm assuming drums, so also could be leaking or seized wheel cylinders, corroded or worn drum surfaces. As the parking brake seems ok, I'd suspect the wheel cylinders. Again, needs to be looked at.

Exhaust leak:
Have a look. Many exhausts have a small drain hole, to allow condensation out, and this also allows exhaust out. This could be what they mean, or a joint may be leaking slightly. Small leaks tend to seal themselves with carbon build up, but if the exhaust is not recent, then this is deterioration, so needs to be looked at to see how long before replacement is needed.

Anti roll bar links are cheap and easy to replace. Do both. You've probably got a knocking over bumps, and this will then go away.

thank you for your reply.
The efficiency is very low inst it. Im super surprised it wasn't noted as an advisory.

Test result shows
Front service brake - LEFT 236 kgf
Front service brake - RIGHT 262 kgf
Rear service brake - LEFT 142 kgf
Rear service brake - RIGHT 171 kgf

Parking brake Rear - LEFT 159 kgf
Parking brake Rear - RIGHT 187 kgf

Your right about rears being drum brakes. I've had a look before when I had new tyres put on and they did look to have rust etc on

And yes, over small bumps in the road, i notice a knocking sound.

I wouldn't know where to start with doing this disk, pad, drum brake replacement tbh.

- Pagid Brake Disc (Front) x 2 @ £34.99 each from ECP
- Pagid Brake Pad (Front) x 2 @ £32.49 each from ECP
- ATE Brake Drum (Rear) x 2 @ £75.99 each from ECP
- Pagid Brake Shoe (Rear) x 2 @ 41.49 each from ECP
(not sure if those items are for one or a pair etc)

that sound correct?

Read a few on here lately with brakes requiring attention. Arm yourself with a Haynes manual, relatively easy job on a car. Indoor/garage job when weather is bad, nice outdoor job when weather permitting. If you feel this is not for you, do you have a friend/uncle/ someone that is handy with the spanners & help/talk you through the process?

That's very low indeed.

I'm at 80% front with 20% parking brake.

Those are distressingly low readings, Here in Ireland a brake performance of less than 55% is a failure! My last NCT was Service brake effort 80%, Parking brake 24%,Parking brake less than 15% is a fail. imbalance front 6%, rear 11%. Parking brake imbalance 7%. Maybe it's not exactly like for like but they do seem on then very low side of low!!!! Given those figures I would strip the calipers and rebuild, clean and lube sliders etc, Check pads and discs at same time, same at rear, strip check and replace as needed, probably change fluid at same time.

Discs are each, but if needed should always be replaced in pairs, to keep the balance.
Pads are always a set, so all you need for both sides, so only one of those needed.
Drums are each, but like the discs, should always be changed as a pair, unless one is seriously gone, and the other somehow still nearly perfect.
Brake shoes, like pads, are a set, so all you need for the rear, so only one set needed.
Be careful with the shoes, they may look similar, but may actually be all four slightly different. Inspect the originals before removal, and match them up.

The job is not too difficult, but if no experience at all, need some help from someone with at least a little knowledge or experience. As said above, first thing to do is get a Haynes. Read it thoroughly, it should either seem ok, or you'll know you need help.

The forum is great for advice, but sadly, we cannot reach through the computer and do it for you. However, tell us where you are, (update your location in your profile), there might be someone nearby willing to help.

He's made a mistake working out your braking efficiencies and splitting them between rront and rear! He can't actually do that because he doesn't know how much weight is on the front wheels and how much is on the rears. He is supposed to take the TOTAL brake test weight for the car from a wall chart in the MOT bay. I don't know what sort of Punto you have, but I imagine the brake test weight will be about 1.75 tonnes. Depending on the age of your car (it changed for cars built after 2010), you need a minimum service braking efficiency of either 58% or 50% to pass. To get this, you add up ALL FOUR brake test figures and divide the sum of the 4 braking forces by the brake test weight of the car by the and multiply by 100. So in your case, that would be:

(236 + 262 + 142 + 171) / 1750 (say) X 100. This gives a figure of 46% (which should be a fail). Working backwards through your figures for both service brake and handbrake, the test weight for your car comes out at 1800kg (which seems quite high for a Grande Punto)! Anyway, whether the service brake efficiency is 46% or 45% is splitting hairs. It SHOULD be a fail! Here's what I think might have happened.

The brake rollers have a grippy surface on them (which eventually wears away and they lose grip on the tyres). When this happens (and when the vehicle is lightly laden) the wheels can lock before they reach maximum efficiency. DVSA take the view that if the brakes are good enough to lock a wheel, then the actual efficiency reading doesn't matter. In this case, the driver's side readings were a bit higher (both on the front and the rear axle). This makes me think the extra weight of the tester in the driver's seat gave it a bit more grip on the driver's side.

So basically, I think your car lost grip on the rollers before it reached maximum braking efficiency, but the tester deemed them to be sufficiently effective to call it a pass. The simple thing, would be for you to go out on a quiet, smooth and DRY road and try an emergency stop. If the ABS cuts in, there's probably nothing wrong with your brakes!

Hi there
thank you all for the response.

When i saw the result of the brake test when getting home i was shocked it was not an advisory, i thought for a moment the lower the % the better!

Anyhow,
Avocet, does this help I found this also on the brake test result paperwork.
TEST TYPE Class IV 'M1 ATL
Braking system Dual line
Before 1.9.2010 - YES
Total vehicle weight 1773kg
Front axle weight 1067kg
Rear axle weight 706kg

Total service weight LEFT 378kgf - RIGHT 433kgf Efficiency 45%
Test result PASS: (Wheel locks)

Its a fiat grande punto, 2008. done 73k miles.

So to clarify portland_bill, to replace all the brakes I would need
All found on eurocarparts

Many thanks guys, i appreciate the help

Hi. This forum has given me the information and therefore confidence to do many things on a van or car. Services are no longer a bother, actually enjoy them. I have friends who have built kit cars and do their own brakes. One thing I won't do are the brakes. Firstly if something is a bit jammed or so on I dont have a workbench for such work or the mix of tools. Next, if I find an issue, it is impossible to put the lid back on and roll it round to a garage. And last, actually most, there are so very many garages who will sort out your brakes and tyres who don't charge very much. . . I just go somewhere I trust. So I service everything apart from brakes myself, go to Mot, and occasionally get the garage to do a full brake inspection when tyres are changed. Seems safe and cost effective. And yes, get them sorted with any hint of a problem, please.

nice one andydiver. I am pretty handy , and with the help of the forum and internet i'm sure i could fathom it out. but like you said. brakes are super important, and a bit daunting tbh. Would you suggest buying the parts and taking them to a garage to fit? or just getting the garage to source the parts and charge for parts+labor?

So there are people who have gone through the Diy pain barriers, know the details now, and who can help you. Otherwise let the garage do all of it. They don't make much money doing it and can find or will stock the parts for less than you will find them. Go all or nothing either way.. .

andydiver said:

So there are people who have gone through the Diy pain barriers, know the details now, and who can help you. Otherwise let the garage do all of it. They don't make much money doing it and can find or will stock the parts for less than you will find them. Go all or nothing either way.. .

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okie dokie good advice thanks andydiver

Rule of thumb here: if you don't know how to do, don't !

Regards, Bernie

Bernievarian said:

Rule of thumb here: if you don't know how to do, don't !

Regards, Bernie

Click to expand...

I certainly dont know how to do it, but I would of given it a good shot. Brakes are a lifeline, and I have kids so I think i'll just bite the bullet and take it to a good garage and pay the bill. I'll also get them to do another brake test as I want the paper work to say my efficiency up where it should be!

chaosengine said:

So to clarify portland_bill, to replace all the brakes I would need

2x Pagid Brake Disc (Front)
1x Pagid Brake Pad (Front)
2x ATE Brake Drum (Rear)
1x Pagid Brake Shoe (Rear)​

All found on eurocarparts

Many thanks guys, i appreciate the help

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That's correct, but don't rush out to buy anything until it has been inspected. Might just all need a good clean-up.
If not certain, let a garage do it.

chaosengine said:

Hi there
thank you all for the response.

When i saw the result of the brake test when getting home i was shocked it was not an advisory, i thought for a moment the lower the % the better!

Anyhow,
Avocet, does this help I found this also on the brake test result paperwork.
TEST TYPE Class IV 'M1 ATL

Click to expand...

Class 4 means it's a passenger car in MOTspeak. M1 is the Euro equivalent (passenger vehicle with up to 9 seats including driver). No idea what ATL means!

chaosengine said:

Braking system Dual line

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All cars have those these days. The braking system is split so that if you get a burst pipe, you will stil lhave brakes on at least 2 wheels. There are various ways to split the system: front - rear is one way (so you always have either rear or front brakes if the other circuit fails. Diagonally split is very common (left front and right rear on one pipe, right front and left rear on the other. There are other ways too, depending on the brakes being used.

chaosengine said:

Before 1.9.2010 - YES

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That just tells them whether you need to meet the 50% minimum efficiency or the 58%. Yours is pre-2010 so it only needs to be 50% efficient to pass (which means you were pretty close when the wheels locked).

chaosengine said:

Total vehicle weight 1773kg

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Blimey! They're fat little piggies! That's a laden weight, of course. But even so, still pretty heavy for a little hatchback. That's the number they use in the calculation I mentioned in the previous post when working out the efficiency.

chaosengine said:

Front axle weight 1067kg
Rear axle weight 706kg

Click to expand...

OK, I take back what I said earlier about them doing it wrong. They DID have a split of the 1773kg between the front and rear axle, so they could work out front and rear braking efficiency separately!

chaosengine said:

Total service weight LEFT 378kgf - RIGHT 433kgf Efficiency 45%
Test result PASS: (Wheel locks)

Its a fiat grande punto, 2008. done 73k miles.

So to clarify portland_bill, to replace all the brakes I would need

2x Pagid Brake Disc (Front)
1x Pagid Brake Pad (Front)
2x ATE Brake Drum (Rear)
1x Pagid Brake Shoe (Rear)​

All found on eurocarparts

Many thanks guys, i appreciate the help

Click to expand...

I'm still not convinced there is anything wrong with your brakes! The efficiency you got could be down to:

1. something wrong with your brakes;
2. something wrong with your tyres;
3. something wrong with the brake rollers.
4. a combination of the above.

In order to pass, your car needs to EITHER manage at least 50% efficiency overall OR be capable of locking each wheel. Your car passed on the latter criterion. Unless you feel that when driving, there is something wrong with the brakes, I wouldn't be unduly concerned. Try the test I mentioned earlier and see if you can provoke an ABS intervention on a dry road. If you can, there's probably not much wrong with the brakes.

Most rear brake drums rust on the outside so they may no need replacing.
So I'd certainly not be buying those unless I was 100% sure of a problem.

The rear pads may though.
As the front discs and shoes may.
The only real way to tell is to investigate.

EvoStevo said:

Most rear brake drums rust on the outside so they may no need replacing.
So I'd certainly not be buying those unless I was 100% sure of a problem.

The rear pads may though.
As the front discs and shoes may.
The only real way to tell is to investigate.

Click to expand...

Am just about to order the parts I need. Minus the rear drums. There is a good sale on at eurocarparts. Will just find a local garage to fit the front disk / pads and rear shoes.

I've began to notice when the car stops after braking a mechanical clunk noise and its very disconcerting.

chaosengine said:

Hi there,
I've just registered to ask this about my MOT pass this morning.

I've just seen the brake efficiency , and it looks very low. They didn't mention it at the time, only when i looked at the document at home and read it now i am concerned.

Front service brake efficiency 28% - imbalance 9%
Rear service brake efficiency 17% - imbalance 16%

Total service brake efficiency 45%
Parking brake 19% - imbalance 14%
​

Test result - Pass (wheel locks)

obviously, the car wouldn't of passed mot if this was super bad, but it looks iffy to me!
New brakes needed?

advisory information:
001 - Exhaust has a minor leak of exhaust gases front [7.1.2]
002 - Anti-roll bar linkage has slight play in a ball joint offside front (drop link) 2.4.G.2


Kind regards,
Thomas.

Click to expand...

Those results don't make sense. If I read the MOT table correctly you need 50% to pass the Service Brake and 16% for the parking brake.


Also odd that the wheels are able to lock up.


What condition are you front Brake disks in? If they are badly scored and the calipers seized then you will have to overhaul.


For the drum brakes on the back check the condition of the shoes, drums and adjusters, that should tell you what needs replacing.


When my handbrake was bad a couple of years ago (2006 1.2 GP) it was the cables which were bad where they were held in at the back. Had to replace them to get a decent handbrake.