Issues with my brakes... Still!

[Metro]

Hi all,

I'm getting very annoyed now! I had an issue where my brakes got progressively spongyer over a period of a few weeks, so i got the system bled and some new braided lines. After it did it again I asked my garage what else it could be and he said the only thing it could be was the master cylinder, so i saved up 300 and got a new mc and got it fitted with new dot 5.1 fluid. The issue has taken a little longer than it did before to emergency but my brakes are getting spongy again!

I checked the system for leaks and its not loosing fluid (even marked the resivoir). Our.. What else could it be? The brakes are solid after bleeding with no play atall!

If anyone has a solution please post =) thanks in advance

Edit: in addition to this, the pedal slowly sinks over this time as well, the biting point of the brakes gets lower and lower untill it hits the floor before braking, it hasn't gotten this bad just yet but it's half way and getting worse over time, if I pump the pedal it rises the biting point for a minute or so

 

[Turbo unit]

Have you bleed all the calipers starting from the furthest away from the reseviour?? Checked all brake lines that any are not bent in any way or damaged??
im just throwing stuff at you this is a hard 1 tbh!

 

[Metro]

Aye, I bled them with an eezi bleed system and the garage has bled them several times since. I even have new calipers on the rear because the old ones were binding. + new disks and pads!

 

[Metro]

Oh and yeah, I followed the bleeding routine I found on here too! I have checked the hard lines and had braided lines put on since aswell and they are all tight with no leeks/bends

 

[Turbo unit]

was the master cylinder bran new?? are you driveing the car hard??? are you cooking the pads what colour are the pads?? if they got a orange look on them then the pads are gone! (again just a fort)

 

[Turbo unit]

you had it on vagcom i this sounds odd but the only other thing that you ent changed are abs module, abs rings, abs sensor soft pedal isnt the normal sytems for this but that is the only things left!

 

[Metro]

I'm not driving it hard to be honest, I like to put my foot down when the times right but don't really use the brakes very hard! The pads are ebc greenstuff and if im honest i havnt had them off since they were put on two months ago, they still have loads of meat on them!

Where abouts in Warwickshire you from out of curiosity, i work. Warwickshire near leamington spa

 

[Metro]

I havnt had it on VCDS but ive got a fault code reader and never had a fault come up for it.. Although come to mention it about a month ago, I took it through a car wash and the abs and traction control lights came on and wouldn't go away, I disconnected the battery for 30 mins and they havnt come back since... I know when audi bled my brakes I asked if they cycle the abs pump and said they do.

Would forcing abs to kick in and seeing if it makes a difference to the pedal be an idea to see if the abs?

Edit: Oh and sorry, forgot to mention, the MC was brand new genuine VAG from Seat (got £50 off from seat over TPS and Audi for the same part)

 

[Turbo unit]

Im in atherstone but my unit is in tamworth....ive got vagcom if you ever in the area:icon_thumright:

 

[Metro]

I acctualy drive past the hinkly junction on the M69 every Friday after work. Any chance I could run past one friday and have a look at what VCDS has to say?

 

[Turbo unit]

what time do you finish and its friday tomoz lol....its about 20mins from hinckley im rite by drayton manor your more than welcome to come down tomorrow:icon_thumright:

 

[Metro]

well, normally friday! im acctually off tomorrow because I had my dissertation to finish off for my degree (I acctually got it handed in today but ive got some other stuff to do tomorrow) but back to work as normal next week! I finish work at 5.30 (in Southam) and it takes 45 mins to get to you.

Although... I am free after 6pm tomorrow and im only in Derby but depends on how late its going to be and me not wanting to take the ****!

EDIT: Funny how I didnt even realise it was friday tomorrow! shows how many days ive lost doing my dissertation XD

 

[Turbo unit]

i shut shop at half 5 bud.....i work sataurdays so if you are free then pop in.

 

[Metro]

cheers mate, not sure if I am to be honest. You say its in tamworth right? whats the address and ill look it up and see if i can pop down some point next week during the day.

 

[Turbo unit]

unit 52 mill lane, fazeley, b78 3qd

 

[Metro]

thanks a lot for the offer! Ill see if I have a free few hours during the day next week. ill drop you a PM when I know

 

[Metro]

Okay, I took the car out in the wet today and got the abs to kick in a few times, this has certainly made the pedal sink further. Could this be air in the abs pump?

 

[Greig300]

My Audi has spongy brakes to. It's caused by the brake servo which is a big job to remove and replace im told engine removal to access....Causes my ESP light to come on until I restart the car. Fault code:

00812 - Brake pressure release solenoid (F84)

I recon that's the fault with yours it's common on Audis across the range from this period.

 

[Metro]

I'm getting no fault codes related to the servo at all which would be a massive expense just to chuck money at. Do your breaks go normal after they are bled then go **** over a few weeks?

 

[Gops]

Did you bleed the MC? And cycle the abs pump too?

 

[Greig300]

My ABS works all disks and pads have been replaced the brakes are spongy... At times it does go harder a little but eventually gets softer again. When I bought the car the ESP light on the dash was covered. When I realised this i later removed the cover over the LED that the last owner left Revealing two fault codes....I then realised Everytime the car went over 15mph the ESP light would stay on permanent until car was re-started...This was traced to the wiring on the haldex ecu was corroded. Took me ages to find that thinking it was pre-charge pumps on the haldex... Or Haldex oil or filters needing done. Anyway the code that was left was the one I posted above. This code does not come back to the servo itsself But is the servo.... a solenoid in the servo called F83 switch. I now get this fault flagging up on a weekly basis intermittently Causing the symtoms you have also the code put the ESP light on disabling the ESP.


Two codes were:

01324 - Control Module for All Wheel Drive (J492) No Communications
00812 - Brake pressure release solenoid (F84)

 

[Metro]

When the MC was changed the garage bled it, but I'm not sure if they cycled the abs pump. I'm going back tomorrow to ask them. Thanks for the replies guys