DIS Warning on startup! BRAKES

[46TheDoctor]

Hi every body just after a bit of help or advice, when i started my 2004 tdi 130 sport this morning the dis bleeped and was showing a warning for my brakes, had a little check round fluid ect all fine, apart from my rear pads look pretty low, i have started my car up 5-6 times since and its not showing the warning anymore, also if i press the "check" button it says all ok, does it do this as an early warning for brake pads or is it anything more sinister, any help on this matter would be appreciated. Cheers Dave

 

[Caesium]

there is no warning system for the back, only the front, although the fluid might be on the limit of warning you due to the rears being so worn (worn pads cause fluid levels to drop).

 

[Olly_K]

could be a faulty sensor. My S4 did it when there was damp weather. dry weather it wasnt a problem.

 

[46TheDoctor]

Cheers guys i will check level properly, also how much did those sensors cost? Also which brake fluid should i use to top up?

 

[petewon]

could be a faulty sensor. My S4 did it when there was damp weather. dry weather it wasnt a problem.

Mine seems to do it when its cold. Was going off ever day last week, not had a problem with it this week.

Also which brake fluid should i use to top up

It should tell you on the top of the filler cap, probs dot 4, but check.

 

[arthurfuxake]

Brake fluid is prone to expansion and contraction by temperature. If your fluid is slightly low, the cold weather causes it to contract, and the sensor warns you. Put a few drops in when the temperature is "normal" (ie not -3degC).

 

[46TheDoctor]

Quite confused cos its only done it the once, and it does not register when you press check button, do any of you think it will have logged a fault?

 

[1210tech]

Cheers guys i will check level properly, also how much did those sensors cost?

the wear sensors come fitted into the new front pads when you replace them, there are two wires connected to a plug on each of the inside pads and when the old pads are removed you just unplug the old plug and plug the new one in when you fit the new pads

 

[TDI]

Like petewon my car did the same thing when it was cold every morning but it seems alright now

 

[Macduff]

Mine (also a 2004 130 PD) has done it a few times. Only when cold and the car is cranky more slowly. I wondered if it was something to do with the vacuum pump (I believe that diesels have one of these) not getting up to speed quickly enough.

Hasn't done it for a couple of weeks now.

 

[cadders]

Mine did it once then was ok for about 10 days before then coming on permanently. Checked the brake fluid, all ok, accepted the enevitable and got the front pads replaced.

 

[46TheDoctor]

Only thing is my front pads appear to have 5mm + left on them.

 

[dan_b]

Sounds like the front pad wear indicator, pure and simple.

Have you inspected the pads on the inside of the discs? These often wear down more quickly than the outside ones due to the floating caliper design.

I'm not sure what the tolerance level is for the pad wear indicators to come on for the fronts.

 

[46TheDoctor]

Cheers Dan, spoke to my mate who was an audi tech till 12mths ago, he said pads are about 70% worn and that the car is likely to start wingeing at me to replace them.

 

[Macduff]

Doesn't really explain why it only happens when the weather is cold and the car is slower to start.

 

[46TheDoctor]

I think you may have a separate issue going on with your car, as whatever the outside temperature my car starts the same every time.

 

[scrupes]

A QUICK QUESTION: does your ignition key properly return to position 2 after starting the engine? I have had a small problem with mine and i have found that the dis brake warning flashes along with the ABS light if the key has not correctly returned???? Dunno what thats all about it's just my car i think, the starter stops turning etc, but if i turn the ign. off and re-start (ensuring the key returns to pos 2) all is well?

I'm gonna get a new key switch to stop this from happening ( another "one of these days" jobs!)
again it makes no difference what the weather or temps are its just a fault with the ign. switch!

 

[46TheDoctor]

Cheers dude i will look next time i go out in it, could you let us know how much your ignition costs and severity of the job.

 

[dan_b]

Doesn't really explain why it only happens when the weather is cold and the car is slower to start.

Could be an expansion/ contraction issue on the metal of the disc and pad itself - in the cold, things shink, so if the pads are marginal, perhaps the contraction due to cold is enough to put them over the edge as far as the sensor is concerned? We could be talking 10ths of mms here. Just a thought.

 

[Macduff]

Could be an expansion/ contraction issue on the metal of the disc and pad itself - in the cold, things shink, so if the pads are marginal, perhaps the contraction due to cold is enough to put them over the edge as far as the sensor is concerned? We could be talking 10ths of mms here. Just a thought.

Possible

Our car has only done 23k and we did 50+ in our Bora without changing pads or disks but then the diesel has much less engine braking so we're almost certainly using the brakes more. Plus the A4 brakes are crap so need to be worked harder.

I'm a bit dissappointed if it is pads as Audi should have pointed it out at the service.

I'll give the pads (both sides) a thorough inspection this weekend

 

[pav-g]

On the current theme my brake light came on early this week also - got the brakes checked by dealers who charged me 21 quid just for looking. Front brake pads are down on my a4 and quoted 173 quid fitted - nearly fell off my chair. Getting them fitted from a local audi specialist for 60 quid fitted. Cant go wrong with that.

 

[46TheDoctor]

Why dont you go to europarts, fit your pads yourself and save yourself 40 quid, itll only take an hour of your time !!!!