matiz 0.8 petrol 1999 brake fault *fixed*

[bluevan]

i've got a strange prob with the brakes on a matiz, the pedal pumps up and holds it's position. but if you take your foot off, the next time you use the pedal it sinks straight to the floor. we've changed the servo, master cylinder, and calipers twice but still have the same problem.
when bleeding them, the pedal falls normally when the nipples are open, apart from the the front nearside, when the pedal remains firm. even though fluid is being ejected.
if we clamp that hose after bleeding, then the pedal works normally and staysfirm and operational after release.
any ideas?

[sb126]

Air in the front N/side calliper, or for some reason the piston is being sucked back into the calliper

Have you pressure bled them?.

[bluevan]

just started this job this week so come in halfway through, no, they haven't pressure bled them, but we're going to later on in the week, i can't see it being anything other than air in the system but it does make you wonder!

[bluevan]

Pressure bleeding is the way forward! all ok and on its way to be mot'd!

[TopGun]

Pressure bleeding is the way forward! all ok and on its way to be mot'd!

It has been for the last 20 years - Where have you been? 

[bluevan]

   first time i've tried it!  always worked on classic cars using old fahioned outdated techniques!

thats why i'm on here, learning from you guys; it's a first rate forum.