Brakes 325 Touring

[Phid]

My car has been laid up for years and so brakes needed seeing to. It's discs all round. I have fitted new hoses and a bit of new pipe where hose unions were rusted. Then bled the brakes until all the old fluid out and new fluid flowing though - over 1 litre of brake fluid so I think all the old should be out. Pedal nice and firm. All brakes seemingly ok - squeezing and releasing ok. When engine switched on the brake pedal travel is increased and they no longer feel firm.

There is a hiss from the passenger footwell behind the servo.

On road test the brakes all seem to work ok - car not pulling to one side and they definitely stop the car - just pedal feel is all wrong.

Non-return valve on the vacuum pipe to the servo seems to work ok - air can only pass one way. When the vacuum to the servo is disconnected pedal is firm again.

So my conclusion is the brake servo but could it be something else? ABS? Need more bleeding?

Thanks

[Phid]

I should add that the hiss is only when I brake. I have since read that this could be due to the insulation behind the servo?

Also bled using one of those one way valve pipes. Think I will do it again the old fashioned way just to be sure

[Phid]

I've rebled the brakes and now feel is ok. At least it was simple. Those 'one-way' pipes must allow a little bit of air back in. Whoosing/hissing sound when pressing the pedal is still there.

[rix313]

As you have discovered, there's a reason bleed nipples are they way they are and don't need people over complicating them with one way valves and other crap inside them.