Advice on works

Banana1983782

Hi

I took my car in for its MOT and it failed on the handbrake efficiency. It was 13%.

The well-known garage told me it needed a new rear brake calliper, rear discs on both sides, and rear pads. £510.

I’m [clearly] not a mechanic, but what I find hard to believe is that discs and pads fitted less than 12 months ago - and only  subject to 9k miles - would need replacing so quickly. I’ve since learned that discs are replaced on both wheels. Frustrating as the other disc (which I asked to keep) is almost pristine! 

I felt I had no choice and needed the car back. But now the handbrake lever is super strong, and I think it probably just needed adjusting, especially given the age of the pads and discs…?

Does the attached disc look like it could have had a new pad and calliper (that had seized) and been OK?

Might all stack up, just curious tbh.

thanks! 

Baldytyke88

It looks older than 12 months, but it looks fine. But what does the other side of the disk look like?

Some would be happy to change just one disk, but best practice would be to change the same at both sides. Did they just replace a caliper at one side?

Garages can rip people off!

The cost of replacing brake pads and discs can vary depending on several factors, including the type of vehicle, the quality of the replacement parts, and the labor costs of the mechanic. On average, the cost of replacing brake pads can range from £50 to £200, while the cost of replacing brake discs can range from £100 to £500. If you’re replacing both brake pads and discs, the total cost can range from £200 to £700.

https://www.atseuromaster.co.uk/services/vehicle/brake-pads-discs

Banana1983782

Baldytyke88 said:

It looks older than 12 months, but it looks fine. But what does the other side of the disk look like?

Some would be happy to change just one disk, but best practice would be to change the same at both sides. Did they just replace a caliper at one side?

Garages can rip people off!

Thanks

They didn’t give me a picture of the other side and I didn’t ask for this disc. I only kept the disc from the other side.

The disc in the attached was fitted in October 2024, so just less than 12 months old. Looks a but rusty, but only surface rust? 

I can see my face in the disc they let me keep and it has zero scoring or rust.

Yes they only replaced one calliper as they replaced the other side with the discs and pads last year. 

Banana1983782

I’d love to learn how to safely change brakes myself! 

Mildly_Miffed

That face is not a pretty thing. Look at the outer portion - it's scraped and gouged away by a pad that was down to bare metal - which is what you'd expect if that piston had seized. A new pad against that would quickly wear to meet it, but it's just... poor not to.

Replacing discs and pads as a complete axle set is basic practice - so I can well believe they'll simply refuse to do it. You're paying for a box full of four pads anyway, and the other disc wouldn't be expensive. Not going to add much to the time, either.

Banana1983782

Mildly_Miffed said:

That face is not a pretty thing. Look at the outer portion - it's scraped and gouged away by a pad that was down to bare metal - which is what you'd expect if that piston had seized. A new pad against that would quickly wear to meet it, but it's just... poor not to.

Replacing discs and pads as a complete axle set is basic practice - so I can well believe they'll simply refuse to do it. You're paying for a box full of four pads anyway, and the other disc wouldn't be expensive. Not going to add much to the time, either.

Thanks.

Discs were £106 each. 

Goudy

As Mildly Miffed states, something has been gouging that surface of the disc.
Presumably the garage are correct and the caliper had seized and the pad has worn down to metal.

All the rust is pretty typical of cars with rear discs.
The rears only handle around 20-30% of the braking effort, the fronts handle the rest as the weight of the car pitches forward under braking.
This means they don't get as hot as the fronts so tend to stay wet and rust faster.
There are discs available with special coatings that resist some of the rusting a while for around the same price as standard discs.

You might also find the nearside of a cars suspension and brakes suffer a little more due to the camber on our roads as the water runs off it to the near side.

As far as the caliper goes, there are a couple of reasons why it might seize.
The piston in the caliper can rust so the piston doesn't move smoothly or if the pads are overly worn the piston can get pushed out at a cocked angle and jam. Plus the more of this piston outside of the caliper, the more prone to rust.

Some rear calipers have a mechanism on the pistons for the handbrake.
Pull the handbrake and a cable (or electric motor) pulls a cam on the back of the caliper that ratchets out the piston in a mechanical twisting motion. (completely independent of the hydraulic system)
As the pads and discs wear it ratchets out further and further and when you change the discs and pads, the piston requires twisting and pushing back rather than just pushing straight back into the caliper.

If the cam that ratchets out the piston is seized, they'll jam on. 

Also, single sided piston calipers "float" on sliding pins. As the piston on one side pushes the pad out against the disc it pulls the caliper towards the other side of the disc, clamping the pads to the disc.
Only one side pushes, but the effect of the sliding caliper pulls the other side towards the disc to trap it in the middle as the whole caliper "floats" on the mounting frame.

These sliding pins are prone to rust, brake dust and road grit gumming them up.
They are usually under little rubber bellows to try and protect them but they should be cleaned and greased every time the pads and discs are replaced.
(with high temp grease specifically formulated for brakes, not normal axle grease as that will burn and catch fire, though some with use Copperslip which is more of an high temp anti seize than grease).

I suspect these pins seizing is what has happened to your caliper, it's pretty common.
These days no one seems to clean and regrease them when any work is done on the brakes and calipers come from the factory with minimum grease on the pins, if any.

Always replace discs and pads in pairs. So either end of the same axle.
If the brakes are in good fettle, you'll not have to go back anytime soon as each side will wear evenly.
If you only do one side, the other will wear out before that side which means you'll have to do the other side sooner than the one you have just done.


Excess wear or quicker wear on one side is a red flag telling you something is not right.

CliveOfIndia

Banana1983782 said:

I’d love to learn how to safely change brakes myself! 

Changing discs and pads is actually very easy on most cars, if you have a modicum of DIY experience and the right tools.  In the past I would have suggested buying the relevant Haynes manual and doing it yourself, but I'm guessing you can probably find a YouTube video these days.  Although, if you're planning to do a reasonable amount of maintenance yourself, I still reckon a Haynes manual is a worthwhile investment - but maybe I'm just an old dinosaur.

Although changing brakes is not technically difficult, it's obviously very important that you do it right, since they're such a safety-critical component.  Personally I'd have no qualms about doing it myself, and have done so since I first started driving (think Fred Flintstone era).  But it might not be a good idea if you don't know one end of a spanner from the other 

Mildly_Miffed

Banana1983782 said:

Mildly_Miffed said:

That face is not a pretty thing. Look at the outer portion - it's scraped and gouged away by a pad that was down to bare metal - which is what you'd expect if that piston had seized. A new pad against that would quickly wear to meet it, but it's just... poor not to.

Replacing discs and pads as a complete axle set is basic practice - so I can well believe they'll simply refuse to do it. You're paying for a box full of four pads anyway, and the other disc wouldn't be expensive. Not going to add much to the time, either.

Thanks.

Discs were £106 each. 

HOW MUCH?

That's steep. What car are we talking about?

For reference, top-brand rear discs for my large Japanese-brand 4x4 are less than half that, and cheapies not much over a quarter.

For the disc to be that gouged, you must have heard the metal-on-metal of the pad for a while, and taken it in for the test in that state...
For a pad to be down to metal in <9k miles, you must have smelt that brake as being hot and noticed the lack of performance and reduced economy...

Banana1983782

Mildly_Miffed said:

Banana1983782 said:

Mildly_Miffed said:

That face is not a pretty thing. Look at the outer portion - it's scraped and gouged away by a pad that was down to bare metal - which is what you'd expect if that piston had seized. A new pad against that would quickly wear to meet it, but it's just... poor not to.

Replacing discs and pads as a complete axle set is basic practice - so I can well believe they'll simply refuse to do it. You're paying for a box full of four pads anyway, and the other disc wouldn't be expensive. Not going to add much to the time, either.

Thanks.

Discs were £106 each. 

HOW MUCH?

That's steep. What car are we talking about?

For reference, top-brand rear discs for my large Japanese-brand 4x4 are less than half that, and cheapies not much over a quarter.

For the disc to be that gouged, you must have heard the metal-on-metal of the pad for a while, and taken it in for the test in that state...
For a pad to be down to metal in <9k miles, you must have smelt that brake as being hot and noticed the lack of performance and reduced economy...

Yes, £106 each and then £118 for rear only pads.

I didn’t observe any noise, any smell, any braking problems, no juddering, absolutely nothing.

Here’s another picture:

Baldytyke88

Banana1983782 said:

I didn’t observe any noise, any smell, any braking problems, no juddering, absolutely nothing.

Here’s another picture:

That disc still looks ok to me, if it were down to the metal, you would have heard a noise when braking.

Garages always give the retail price of parts, but they get them much cheaper.

Brake discs are generally replaced in pairs and cost on average around £75 each, fully fitted, but can cost from as little as £30.

https://www.national.co.uk/brakes/