Brake Bleeding W202

[peter h]

Replaced the pipes from master cylinder to ABS unit yesterday, have bled the system (twice) today but the pedal is still spongy. I am assuming that there is air in the ABS unit, is there a particular procedure I need to follow to bleed this (bleed with engine running??)? I have a pressure bleeding kit that is safe up to 20psi. Car is a 1998 C180.
Thanks in advance
Peter

Worked on Ford Cortinas for the last 20yrs, this is all a bit modern for me

 

[para alpha]

Replaced the pipes from master cylinder to ABS unit yesterday, have bled the system (twice) today but the pedal is still spongy. I am assuming that there is air in the ABS unit, is there a particular procedure I need to follow to bleed this (bleed with engine running??)? I have a pressure bleeding kit that is safe up to 20psi. Car is a 1998 C180.
Thanks in advance
Peter

Worked on Ford Cortinas for the last 20yrs, this is all a bit modern for me

I assume you used the old pump, hold, release, tighten method? Try to bleed them with the ignition on. Some cars need to be done with the motor running (Precarious I know)

These things can be a little temperamental, Now! You may have to use your pressure bleeder to actually pull the fluid through. No doubt others will have different methods....

 

[peter h]

Thanks, re-bled the system tonight with the engine running and all is working properly. Used the pressure bleeder at 20psi.

 

[para alpha]

Thanks, re-bled the system tonight with the engine running and all is working properly. Used the pressure bleeder at 20psi.

good to hear Peter!

 

[Dieselman]

I don't see how having the engine running makes any difference as the master cylinder is fully retreated either way.

A pressure bleeder should ensure a good bleed, but if having trouble compress all the brake caliper pistons to create the smallest volume for air to get trapped in.
It does work.

 

[para alpha]

I don't see how having the engine running makes any difference as the master cylinder is fully retreated either way.

A pressure bleeder should ensure a good bleed, but if having trouble compress all the brake caliper pistons to create the smallest volume for air to get trapped in.
It does work.

It's something to do with purging the ABS Pump. I know of some Vauxhalls that need the ignition on or engine running to ensure the brakes bleed properly. Maybe a tech could shed some light on it Although, I know about compressing the pistons in the callipers method...