Clutch Hydralic Issue - Help! Have Tried Everything

[Simon-S14]

Ive got this clutch hydralic issue that i thought i solved... Basically i can bleed the clutch system, then after a while of driving (say an hour or so) the engagement point gets higher and then with your foot off the peddle there is still pressure in the system and applying on the clutch fork causing the clutch to slip under hard accel

Cracking the bleed nipple on the slave/master (i have ditched the damper in the middle) releases this pressure and all is good for another hour or so...

Now heres the thing, i have rebuilt both the master and the slave, and adjusted the pushrod on the master, but with no solution. The only thing that made a real difference was using an air blower to blast all the lines out and chucking the damper in the bin... then the clutch was fine for a day or so then it was back to acting up.

Slave cyln looks to be perfect, as does the master, so really. im stumped and sick of the damn issue!

[blind_elk]

You're sure you have the pushrod adjusted correctly at the pedal. Because it sounds like the master is gradually building pressure because it can't release properly. Pretty certain there should be a slight amount of slop in the pushrod when the pedal is fully released.

[Simon-S14]

thats exactally whats happening, master is building pressure, however the pushrod has plenty of slop in it after bleeding.... but it doesnt stay that way!

hair pulling stuff

[kjb_r33]

thats exactally whats happening, master is building pressure, however the pushrod has plenty of slop in it after bleeding.... but it doesnt stay that way!

hair pulling stuff

Compensating port is blocked, fluid heats up and cant return to reservior, therefore it expands and disengages clutch. If you have freeplay at adjustable rod you need to make sure the port isnt blocked.

[blind_elk]

You haven't put something in arse-about when you rebuilt the cylinders?

[Simon-S14]

Compensating port is blocked, fluid heats up and cant return to reservior, therefore it expands and disengages clutch. If you have freeplay at adjustable rod you need to make sure the port isnt blocked.

where about is this port located?

[kjb_r33]

where about is this port located?

If your looking into the master cylinder, it the small hole closest to the main bore opening. If its out of adjustment the seal will cover the port, stopping the warming fluid from re-entering the reservoir.

[Simon-S14]

so basically i need to strip it down and clean it all out...

[kjb_r33]

so basically i need to strip it down and clean it all out...

Yep, but you also need to make sure you havent fitted a spacer or washer in the wrong spot. In the relaxed position the seal needs to be slightly back from the compensating port.

[Simon-S14]

thanks for that mate i shall get stuck into it...

[T04GTR]

you need to back the master cyl push rod off.

[T04GTR]

how is this slop mesured? if the clutch switch has been adjusted aswell it needs to be backed off aswell.

[Simon-S14]

the peddle has a good 10-20mm freeplay before it starts engaging the clutch, this is just after i bleed it, then after a drive it all changes

[dead32]

why not just buy a new master? very cheap and save all this hassle.... rebuilding is fine but for all the hassels youve had id just f**k it off and get a brand spanka. you could possibly have the seals in the wroung way also... primary/ secoendry seals backwards etc.

[Simon-S14]

im thinking about it! How much and where from, and part number?

[Jax]

Compensating port is blocked, fluid heats up and cant return to reservior, therefore it expands and disengages clutch. If you have freeplay at adjustable rod you need to make sure the port isnt blocked.

This is the right answer, you don't need new! Find out, in your assembly of the master, why the seal is covering the hole so the fluid can't return to the reservoir.

[Cubes]

I have been through a couple of aftermarket clutch masters and 1 slave cyls.

$75 for the master and $38 for the slave.

The aftermarket master behind a 1+tonne clutch doesn't last too long I average ~40,000km's before they begin to leak. :S

All clutch brake Edwardstown.

I'll go a genuine master and nismo slave (reduced pedal effort) next time roud as I'm sick of removing and installing.

[Simon-S14]

I have been through a couple of aftermarket clutch masters and 1 slave cyls.

$75 for the master and $38 for the slave.

The aftermarket master behind a 1+tonne clutch doesn't last too long I average ~40,000km's before they begin to leak. :S

All clutch brake Edwardstown.

I'll go a genuine master and nismo slave (reduced pedal effort) next time roud as I'm sick of removing and installing.

your telling me.. its a fair prick of a job to remove it all, ive done it about 3-4 times now (once cause my clutch peddle box broke)

i'll pull it out and strip the master down again. no idea where this compensating port is but i'll try and figure it out