Brake Pedal

[acecard]

Hi guys, not been on for a while - the mk3 has been mostly behaving itself apart from a creaking clutch pedal which seems to respond to a heavy dose of WD40 but the squeak reappears after a couple of months. Not in itself a major issue though b***y distracting every time you change gear.

Anyhow, while sorting out the clutch pedal, I noticed I could press the brake pedal (with my hand) further than i expected so I pumped it a few times and lo and behold,  it became firm near the top of its travel, much like what would happen if there was air in the system and the brakes needed to be bled. However, while I was doing this pumping, there was a sort of 'hiss' noise like air was involved somehow.

I left it a few hours and then checked again and the pedal wa still firm - but as soon as I started the engine, it returned to its 'spongy' state (not that I am having a problem with brakes, all seems fine). When engine is stopped I can go through the process of pumping and hissing again.

Is this normal or is there a problem here? Thanks in anticipation for advice

Cheers

[chrispb123456]

If the hissing is only when pressing the brake pedal then that sounds like the servo diaphragm is leaking, the other actions you describe is normal

[acecard]

Thanks for that