Soggy brakes - your thoughts please

[Bunglebonce]

Further to my post a few weeks ago about my brakes being soggy, I took them to a stealer yesterday for a check.

They said they could find no fault / leak / computer generated info to suggest there was a problem.

They also checked the tandem fuel / vacuum pump and checked with seat UK to see if it had any recalls on it - nothing.

The one chap said he had an FR tdi for a while and that his felt no different.


However, I am positive that in the last 2k the problem has worsened to the extend where when moving around in slow traffic, being able to slow to a gentle halt is impossible - more like nothing then grab! (nose on windscreen).


Admittedly when the bloke checked them, the fault had be recorded wrongly on the log sheet so he was looking for a "hard" pedal
Still, they did not try and fob me off suggesting I booked it back in and they'd have another look at it possibly bleeding the breaks this time.

Thing is, if there are no leaks, how can air have got in the system in the first place

I know there is an issue here as the pedal was firm from the top when I had the car allowing for progressive breaking even at the slowest speeds. This was backed up when my dad drove the car the other week and said "bloody hell what’s up with your brakes!"

I am not losing the plot!

What could it be and how can I demonstrate there is a problem with no way of showing the before and after situation.


Its starting to p1ss me off now

 

[m0rk]

maybe you've cained your pads. they're only little, but if you've over heated them (or the disc) they may be glazed

 

[Bunglebonce]

maybe you've cained your pads. they're only little, but if you've over heated them (or the disc) they may be glazed

Dont think their glazed as the lack of brake is due to the lack of pedal at the top of the stroke rather than the pedal being firm but showing little braking resistance.

Good thought though.

Im sure its a vacuum leak or air in the system but how the hell can air get in if there is no fluid loss



Anyone else

 

[Sam20v]

do you think it may be another case of COMPUTER SAYS NO!!!!!!!

maybe you should just change the brake fluid and flush any air through.....i no you said no obvious way air can get in but strange things happen....
worth a shot

 

[mik]

Sounds like a servo or master cylinder prob to me.

Sounds like the brakes do work - it's the modulation that's not working. This implies that either the master cylinder isn't running smootly, or there is something wrong with the servo diaphram movement so you're getting inconsistant assistance.

 

[Bunglebonce]

Sounds like a servo or master cylinder prob to me.

Sounds like the brakes do work - it's the modulation that's not working. This implies that either the master cylinder isn't running smootly, or there is something wrong with the servo diaphram movement so you're getting inconsistant assistance.

Cheers Mik, I'll throw that at them when I go back.

It's difficult to prove there is a change if they have nothing to compare it with but if your just rolling at say 10mph, you would expect to be able to gently squeeze the pedal to come to a gradual and steady halt wouldnt you?

It's impossible - no brake for a good inch then it comes in slightly, then grabs resulting in sudden uncontrolled stops.

Obviously this is less obvious at speed as you need loads more brake to scrub the speed off so you go past the initial soft pedal bit.

Whats concerning me is if they bleed them and its the same, where do I go from there?

I know there's a problem but how can I prove it?


Cars eh

 

[Bunglebonce]

Hi I've resurrected this thread as I still have a problem!

Original there was a minor improvement after it was put through the abs machine, but over the last 20k its crept back up to the point where the brake performance is questionable to say the least.

These are the issues:

1. Well over an inch of pedal travel until any brake at all - then, wallop it all comes in at once.

2. If I pump the pedal whilst the engine is ticking over to kill the vacuum, it goes hard, but then creeps back down again very slowly (ooer missus ).

3. Three times in the last week I have felt the car pull to the left on braking.
The first time was as I came to a halt at some lights where the steering wheel span to the right; the second was just a minor twitch whilst slowing in a 30 zone but the 3rd time was on the M6 Saturday night when having braked hard to avoid a wandering car from hitting my front wing, the car pulled violently to the right nearly hitting the slip road barrier at junction 6!


This cannot be "nothing" can it???

Any thoughts chaps before it goes in to the dealer Friday???