Hi guys and girls, the brake pedal from hell comes to haunt me, after issues with brake fade from new discs and pads, had them replaced now it stops very well, but now the pedal creeps and I get that sinking feeling, my question is, would this be air in the system, pedal is hard with engine off, if I hold the brakes on and start the engine the pedal travels 3-4 inches then goes spongey, can someone put me in right direction, thanks
I know this issue has been going around (the world), for many years now, but this is the first time, I’ve encountered it.
Recently replaced the ‘Master Brake Cylinder’, all four discs, pads and callipers, on my wife’s LWB 2005 Defender, TD5 .
Bled the brake system and the brakes were fine with the engine off, (pedal rock hard), however, once the engine was started the brake pedal would creep to the floor, under medium foot pressure. After many attempts of ‘pedal’ and ‘pressure bleeding at 20psi’ there was unfortunately, no change.
I then decided to try the use a vacuum pump. First, I removed the pipe for the ‘front left’ wheel on the ABS modulator, then connected the vacuum pump with an improvised link consisting of a brake pipe fitting, copper pipe and clear neopreem tubing. Being lucky enough to have a ‘nanocom’, I activated (alternately), ‘Front Left Inlet Valve’ and ‘Front Left Outlet ‘Valves, whilst the vacuum pump was activated. Shortly after a continuous stream of bubbles were drawn from the abs modulator!
I then went on to peddle pump bleed the system in the ‘normal’ way and hey presto!
Sinking peddle sorted!!
My view maybe wrong, but peddle and pressure bleeds are fine, as long as the brake fluid remains in the system. Once fully drained, you will need a vacuum pump to clear air from the ABS Modulator.
Bex.