clutch problem please help

[v33tra]

ok one of my vectra c`s is driving me up the blooming wall ( well it would if i could get it to drive any great distance reliably )

ok the car details

2004 vectra 2.0 dti ( y20dth )

the problem

dual mass flywheel was rattling and the clutch started to slip

work carried out so far

dual mass flywheel replaced

clutch replaced

clutch cover replaced

concentric slave cylinder replaced

all flywheel bolts replaced

clutch cover bolts replaced

gearbox oil replaced

all the above brand new parts

car put back together clutch system bled and car road tested



NOW A NEW FAULT ARISES

this is what i need help / advice with

the clutch is bled up peddle feels great biting point good until you road test it a couple of miles then clutch peddle starts to fade away until biting point is on floor and little or no resistence to peddle gear changes become difficult

bled system again same scenario occurs within 2 miles,this system has now been bleed manually and with a pressurised bleed machine over 20 times still same fault occurs

so today a brand new clutch master cylinder is fitted and clutch spring modification carried out i.e the one that fixes cruise control

bled system up road test same fault occurs again,5 more times i`ve bled the system up clutch peddle continues to fail on road test

no fluid loss on any of these road tests is apparant and reservoir level remains same and the peddle gets better by pumping it several times but fades away again when driving

this is deffo an air in system fault but i can`t source the cause or cure it however it may be a faulty new slave cylinder but how can i prove that without having to remove the gearbox again

any advice really gratefully recieved if anyone has encountered similar vectra clutch bleeding issues

my next course of action in the meantime is to replace the hydraulic flexi pipe that feeds the slave cylinder but that wont arrive until saturday

thankyou in advance if you reply with advice

[jonnybravo]

vx have come up with a revised bleeding proceedure it's worth a try.
fit a rubber tube to ventilator valve,put open end into a clean container with enough brake fluid to cover tube end,press cluth pedal to floor and hold there,open valve untill fluid runs out without air bubbles (you will need someone in car to hold down pedal)close valve,then pull pedal back to stop but not too quickly,wait 5 seconds,repeat this 4 times tighten valve (not too tight 5 Nm)don't forget to keep resorvoir full all the time.top up fluid and test drive vehicle.
it's a bit of a fiddle but worth a try bud,
air get's traped in system because of vx's poor design (surprise surprise)

[benny]

could be two things .....is the clutch drive plate in the correct way round ? ...... if it is in the correct way i would go for the clutch master cylinder the seal could be week / letteing in air .....

[v33tra]

vx have come up with a revised bleeding proceedure it's worth a try.
fit a rubber tube to ventilator valve,put open end into a clean container with enough brake fluid to cover tube end,press cluth pedal to floor and hold there,open valve untill fluid runs out without air bubbles (you will need someone in car to hold down pedal)close valve,then pull pedal back to stop but not too quickly,wait 5 seconds,repeat this 4 times tighten valve (not too tight 5 Nm)don't forget to keep resorvoir full all the time.top up fluid and test drive vehicle.
it's a bit of a fiddle but worth a try bud,
air get's traped in system because of vx's poor design (surprise surprise)

already tried that method but still the pedal fails

thankyou for taking the time to advise of it though any help gratefully recieved

[v33tra]

could be two things .....is the clutch drive plate in the correct way round ? ...... if it is in the correct way i would go for the clutch master cylinder the seal could be week / letteing in air .....

master cylinder was replaced with a new one today and fault still there

99% sure clutch plate is in correct way although 1% of doubt the more i think about it

why would that cause this fault if you can explain in detail as we can bleed up a great feeling pedal and good biting point it just fades away to a crap one after a few miles but bleeds back up easily again

also pumping pedal a few times when driving improves the biting point and pedal feel but it fades away again with use until you pump it again

thankyou for replying and welcome any more thoughts

[jonnybravo]

if it pumps up as you say then you lose pedal it has to be master or slave cylinder,the fluid is by passing the seal and pumping up re prime's the cylinder.that's assuming you arn't losing any fluid externally

[benny]

are the seals on the pipes that go into the box and come from the master cylinder all ok one hasnt peeled over or has a nick in it ..?

[vxr-jim]

pretty sure you have a faulty hydraulic valve.

on your actuator pipe, follow it back to the master cylinder, there is a round valve, almost the size of 2 jammy dodgers stuck together on the pipe, these cause symptoms like this, they draw air through the seal and therefor spongey clutch.

the valve is black or silver depending on model.

[v33tra]

pretty sure you have a faulty hydraulic valve.

on your actuator pipe, follow it back to the master cylinder, there is a round valve, almost the size of 2 jammy dodgers stuck together on the pipe, these cause symptoms like this, they draw air through the seal and therefor spongey clutch.

the valve is black or silver depending on model.

this is ordered VOR today but won`t arrive until tuesday worth a try as it`s the last external part also comes with the metal pipe if that fails to cure the fault it`s gearbox back out

[v33tra]

are the seals on the pipes that go into the box and come from the master cylinder all ok one hasnt peeled over or has a nick in it ..?

as far as i can tell mate by tuesday every external part will have been changed and the only things after that left will be the bleed nipple housing the metal pipe in the gearbox and the new slave cylinder itself but these 3 parts require gearbox removal to check again that they are ok