Brakes - Pedal to Floor

[Alan_M]

Been pulling my hair out for the last couple of weeks. Had a cruddy looking brake line from the front to the rear of the car which I replaced along with each hard line to the rear calipers. Bled it all through with an Eazi-Bleed and then activated the ABS pump on PP2000 just for luck. All bled through fine.

Go to pump the brakes, they go hard as expected. Press the pedal again about 5 seconds later and it goes to the floor. Shagged master cylinder I thought, so ordered and fitted one. Bled through and brakes are the same, going to floor. 

Just been out again and tried dislodging any trapped air by winding back the rear pistons and bleeding through using the 2 man method. Strangely, when bleeding through the rear passenger, the fluid came out milky (water getting in) then cleared. Pedal still goes to floor but I think it feels stiffer.

• Engine OFF - Pedal goes to floor but gets hard after 2 pumps. Holds under pressure but if you let off and go back after 5 secs, the pedal goes to the floor again.
  

• Engine ON - With foot on a hard pedal, turning engine on, pedal drops a touch as expected. Let off pedal for 5 secs, pedal goes to floor. Pump the pedal and it'll go firm again. Under pressure, the pedal creeps to the floor.
  

• There is definatley vacuum, and the one way valve works as expected. With no vac attached and engine running, pedal goes 3/4 to the floor. It firms up again after a couple of pumps.
  

I'm going to re-bleed again tomorrow, as the milky fluid makes me think there is still some trapped in there. Also, reading around the servo's on these can cause similar symptons (it hisses intermittently). I really hope it's not the servo as that looks a right twat to change!

[Rippthrough]

It's not the servo, it's a fluid issue.

[Eeyore]

sounds like an airlock somewhere. Is it leaking anything?

[Alan_M]

sounds like an airlock somewhere. Is it leaking anything?

No leaks at all. I've lost count how many times I've bled it using 2 man method, one-way valve, Eazibleed and PP2000!

[Rippthrough]

Might have a weep on a joint letting it drag air in - hence the milky fluid one side.

[C2K]

Did the new brake line have the correct flares to seat properly?

[Alan_M]

Copied what came off (original pipe), all single male flares from what I remember.

[Alan_M]

Spent most of the afternoon bleeding this through using a one-way valve. 2 litres later of fluid and we have a consistently firm pedal!

The milky fluid must've been a lots of very fine air bubbles as there is no milkiness in the capture tub. It was the rear passenger and front drivers that were full of it! Gave the diagonal method a try after reading about it on the Berlingo forum.

I think I'm going to plug in PP2000 and bleed a bit more tomorrow as there still traces of air in the front drivers caliper. The pedal is at least firm now.

[C2K]

Chances are if you emptied the system there was air trapped in the ABS. You can cure this by cycling it on a gravel car park, doing a good 30 miles or so driving then re-bleeding and it will be waiting at a nipple.

[welshpug]

never had abs issues even from dry.

[C2K]

I have, multiple times. Doesn't normally result in pedal to floor granted. PP2K opening the ports should've helped with this, but it's free to try regardless.

[Alan_M]

This is the first time I've had this, always managed to get a firm pedal with an Eazibleed.

Anyways, pedal is now spot-on and the 306 is going better than ever.