Pedal goes soft on ignition and foot goes to floor

[finch wxm]

As you maybe aware I'm having issues with my brakes , I'm currently getting to pedal feel and the brakes are not working what so ever .

Calipers were off the car for some time and no lines were on car during my build so I'm thinking master cylinder maybe knackered .

We tried bleeding brakes last week and get air out the lines .

The pedal will go hard if I pump with ignition off but as soon as I turn the ignition on pedal goes soft instantly and pedal goes to the floor , would this suggest the cylinder has gone ?

 

[Pauleds]

Still air in the system

 

[bashracing]

ignition on or engine running, if just with ignition on it's the abs modulator

 

[car.crash]

This would suggest your servo is working fine and you still have air in your brakes.

 

[finch wxm]

It's when I fire it up . Pedal is soft until I pump brake with ignition off . Fire it up pedal goes to the floor . Can't get any decent resistance and no brakes .

Will have rs tuner software for abs next week .

People think master cylinder is working then and doesn't need replacing ?

 

[tomhunt85]

I've had/got a similar problem. The only thing it can be now is the servo, changed everything else. It's in the garage on Tuesday again so I'll let you know how I get on. Wasn't my master cylinder or ABS pump.

 

[finch wxm]

Yeah keep me posted buddy . My car has been on the road 4 years which probably doesn't help things ha ha

 

[barnesautos]

What you need to do is get some seriously long bleeding pipe and run the pipe from each nipple in turn of bleeding order and run the pipe back into the fluid reservoir and bleed each line and caliper and watch and see if any more air bubbles arrive at the reservoir .
Don't forget the amount of fluid in the long line will need to be topped up in the reservoir b4 it reaches it
This way if the fluid level drops from where it was when started - it's replaced the air which is a good sign. Do this first B4 you replace anything

 

[bloke]

as previous, mityvac and abs set to bleed.

 

[tomhunt85]

Yeah keep me posted buddy . My car has been on the road 4 years which probably doesn't help things ha ha

Still presuming it's the servo, may never get to the bottom though as there was a small-ish fire in the car and the servo, MC and a few other bits are a bit hot and melted. Good luck with solving it :disrelieved:

 

[finch wxm]

Jesus , what's happened ? I'm going to collect another clio next week as a daily but may have alook at this over the weekend if I get chance

 

[tomhunt85]

Split fuel return it appears, lucky that it wasn't much worse.

 

[finch wxm]

Gutted buddy , hope you get it all sorted

 

[tomhunt85]

We'll see, big bill anticipated. Likewise, hope you sort yours.

 

[finch wxm]

Got my rs tuner and abs software now , just need another set of hands to help but I have ABS faults on diagnostics .

I have noticed that drivers side rear will not rotate , looks like piston has seized as the pads are preventing disc from rotating .
Would this have an effect of the bleeding process at all ?