Low pad warning lamp, but pads are fine

[eltax91]

Thread updated on page 2

Hi all,

I'm away visiting relatives at the moment and cruched through 150 miles this morning. About 2 miles from the destination, the low pad warning lamp illuminated. The car is a Mk1 octavia.

I've looked at the front pads through the alloys and there is loads of friction material on the pads, both sides. Obviously, without any tools I can't see the inboard pads to know if they are worn, that would be unusual though wouldn't it, for inside to wear significantly than outside?

Are these cars known for throwing false pad readings? Not sure I want to take the return journey tomorrow without putting my mind at rest about the brakes!

Edited by eltax91 on Monday 27th August 14:20

[cuprabob]

Low pad warning is very conservative and comes on when there is 2mm of friction material left. It's not unknown for the inner pad to wear faster than the outer especially if it's a single piston caliper with a slide

[bamberwell]

broken sensor wire? happened to me before a couple of times....

[eltax91]

cuprabob said:

Low pad warning is very conservative and comes on when there is 2mm of friction material left. It's not unknown for the inner pad to wear faster than the outer especially if it's a single piston caliper with a slide

Thanks for the response. When I say loads of friction material left on the visible pad, there is more than 10mm left. I'd be very surprised if they have worn differently to that extent.

Is it possible for the wear sensor to come away from the pad and throw a false positive?

Also, any mot testers confirm if the light is a fail. Mot not due for 3 weeks, but test booked for Wednesday!

[eltax91]

bamberwell said:

broken sensor wire? happened to me before a couple of times....

This is my current school of thought to be honest...

[rash_decision]

At 10mm I would reckon on a broken wire. The only way the inboard pad would wear that differently is if you had a sticcky caliper/piston/slides.

On a side note, I do know from seeing it many times, VW/Audi group pads do light the warning lamp when there is plenty of meat left on the pads!! Not quite at 10mm of course!!

[AJB]

eltax91 said:

Obviously, without any tools I can't see the inboard pads to know if they are worn, that would be unusual though wouldn't it, for inside to wear significantly than outside?

I think I'm right in saying that there's only a sensor on one half anyway, and I think it's the outboard ones, in which case the inboard couldn't be triggering the light even if they were significantly more worn. Which they probably won't be.

The new pad comes with a sensor built in and a short bit of wire ending in a connector. I haven't heard of the sensors failing, but the connector might not be making good contact or a wire might have broken. Or it's possible that someone's fitted pads without a sensor and bodged it by shorting out the connector, but their short has come adrift.

[AJB]

One more thought - does it have discs on the back? I know the drum brake rears don't have a sensor, but I don't know whether the disc ones do or not. What are the rear pads like if it's discs?

[eltax91]

This is my first 'mk4 golf a like' car. The wear sensor is on each of the front only inside pads. It's not on the outside, and there are no sensors on the rear.

I'm feeling, if I can't find a garage open tomorrow, to make the north wales to leicester journey home and then strip the fronts down when I get back and see if there is obvious odd wear, or the sensor looks broke/ bodged.

[Eighteeteewhy]

The outside pads are fine. But the inside ones(you can't see) could be down. Worth taking the wheels off for a look.

[Negative Creep]

brake fluid level?

[smileymikey]

They are set to come in in plenty of time to have them changed 1500 miles as a conservative minimum. Drive home normally and have a look when you get back.

[AJB]

eltax91 said:

The wear sensor is on each of the front only inside pads. It's not on the outside, and there are no sensors on the rear.

OK - sorry - I had remembered that the wrong way round. It might only be one side that has the sensor too, rather than both sides. Again, I might be making that up though!

eltax91 said:

I'm feeling, if I can't find a garage open tomorrow, to make the north wales to leicester journey home and then strip the fronts down when I get back and see if there is obvious odd wear, or the sensor looks broke/ bodged.

Yes - you'll be fine to make the journey. Even if the pads are low, the light should come on with plenty more than wales to leicester left in the pads.

[AJB]

Negative Creep said:

brake fluid level?

That's a different light, and red not amber. Brake fluid level is often the same light as the handbrake on. Brake pads low would be an amber warning light, with a dotted line for the shoes in the brake symbol.

[cuprabob]

The backing plate on the pad is around 8mm thick so as long as you're not including that in the 10mm then there is good chance it's a broken wire. New pads have around 12mm friction material on them, so they can't be that old.

I agree if the outer pad has 10mm friction material then the inner pad will have plenty of life too

[Ozzie Osmond]

cuprabob said:

Low pad warning is very conservative

^^^^ This

[eltax91]

AJB said:

hat's a different light, and red not amber. Brake fluid level is often the same light as the handbrake on. Brake pads low would be an amber warning light, with a dotted line for the shoes in the brake symbol.

Yep. My light is an amber circle, with three marks around each side. Reminds me of a brake drum design, funilly enough!

I will pop a front wheel off if its not raining, if it is, I will drive home and look at it in a dry garage.

[Cerberus90]

On my mums Fiat 500, which we just had to change the pads, one pad, can't remember if it was inner or outer, think it was an outer one as no light came on, had worn down to the backing material, the other pads had about 15-20mm of material left.

The calipers didn't seem to be sticking either and moved fine when we'd taken the pads out. Apparently, it is a common problem on the 500. From what I read though it was calipers sticking as no copper slip was used on the sliding pin in the caliper, but ours seemed fine.

[AJB]

eltax91 said:

AJB said:

Brake pads low would be an amber warning light, with a dotted line for the shoes in the brake symbol.

Yep. My light is an amber circle, with three marks around each side. Reminds me of a brake drum design, funilly enough!

Yes - I think the light design is older than disc brakes! The 3 marks are showing that the (drum brake) shoes are partly missing.

eltax91 said:

I will pop a front wheel off if its not raining, if it is, I will drive home and look at it in a dry garage.

Sounds like a very sensible plan.

It was quite a few years back that I changed brakes on my Octavia. I think my inner left pad was more worn than the others, and my light hadn't come on. So, if there's only one sensor and it's on an inner pad, then I'd guess that it's on the right hand front wheel. So maybe go for right front if it stops raining!

[H100S]

Sometimes the caliper piston does not return fully causing the pad to wear faster. This could cause excessive wear. Your inner pad will be worn more on the inner side.