Bleeding brakes!!

[nedflanders]

TD5 90 2003 ABS
I started to get a soft brake pedal about a month ago, not bad but something not quite right, 1 pump and it's OK until I next use them. I bled them through a month ago as the fluid was getting old and had a really good pedal, until now and it's started to go soft again. Must have bled 2 litres through it. No signs of leakage and the pads are new. Any ideas?

[djam1]

Did you bleed the modulator??
They have a lot of small air pockets in them that are difficult to get all of the air out of.
You may need a Nanocom or Hawkeye to bleed the modulator properly.
That said I have never HAD to do it just found it easier

[jboot51]

Just a heads up,
A loose/bad wheel bearing will cause the pads to knock back, giving the feeling of bad brakes on the first push and ok on the second.

[nedflanders]

No problems with bearings or brake discs?? No reason why any air should have gotten in the system??? plus after bleeding its ok for a few weeks, anything like bearings/discs would be fairly immediate.

[460cixy]

New pads on old rotors will give a **** pedal

[Flipper]

TD5 90 2003 ABS
I started to get a soft brake pedal about a month ago, not bad but something not quite right, 1 pump and it's OK until I next use them. I bled them through a month ago as the fluid was getting old and had a really good pedal, until now and it's started to go soft again. Must have bled 2 litres through it. No signs of leakage and the pads are new. Any ideas?

My gut tells me the master cylinder needs repair from your description.
I have seen this symptom all to often which normally shows the master cylinder is stuffed.
Worth checking all other things over first but my money is on the master cylinder.

[Backtabush]

If its showing air bubbles in the system when you bleed it i would say master cylinder getting tired each time you release the pedal as it return back the rubbers cups are not under pressure and very small amount of air can be drawn in thru rear cup seal and may not show sign of leak yet mine got 270ks up and just starting to bypass when pulling up at lights under light pedal pressure you feel the pedal travel more than under normal braking or if your sitting at the lights and you relax the pressure a bit you feel the pedal start to creep towards the floor you know to start shopping around.

[Lorryman100]

A quick test you can do to see if the Modulator needs bleeding is to get the TC or the ABS to operate. Loose gravel, beach sand and shingle are idea. If after the ABS/TC operates and the pedal firms up, then you have your answer. If this is the case then you will need to do a Master cylinder bleed first followed by bleeding each caliper starting with the furthest from the modulator and finishing with the closest. The other option is to use a diagnostic tool to operate the modulator pump.


HTH Brian.

[nedflanders]

New pads on old rotors will give a **** pedal

As long as the rotors are good then no, gotta disagree, seriously do you change rotors everytime you change the discs??

Kinda agree with the master cylinder, prices over here are once again taking the **** so another order back to UK. Genuine UK £190 or Aus $800+ LOL!!!

[460cixy]

As long as the rotors are good then no, gotta disagree, seriously do you change rotors everytime you change the discs??

Kinda agree with the master cylinder, prices over here are once again taking the **** so another order back to UK. Genuine UK £190 or Aus $800+ LOL!!!

It don't work like that the rotors not flat. You put new pads in that are flat and what do you think is going to happen? They just bend out of shape every time you stand on the brake I see it all the time customer puts new pads in car won't stop they come in and can't beleave its there me pads giving them a **** pedal it may not be your problem but it sure as **** happens