Technical 2008 Fiat ducato 3.0 mwb clutch AGAIN

[Marmitethecat]

HI All,
recently i had the gearbox replaced as it was crunching into 3rd. as the slave cylinder was only about 20,000 miles old i thought i would be ok to reuse it. BUT about 1 month after the gearbox swap im having problems.
Sometimes when i push the pedal down it only returns half way up. If i pull the pedal up sometimes it works properly, but sometimes it will 'flick down' to the half way make. From half way to the floor the clutch feels a bit stiffer but works and then it will appear to fix itself.
Ive also noticed if i keep pressing repeativily on the freeplay at the top of the pedal travel, it starts to increas by about 1cm of drop.
Brake fluid i was replaced with the clutch slave cylinder in 2021( 20k ago), there is NO VISIBLE leak, damp patch on the bell housing or on the road.

Previously before i replaced the clutch slave cylinder.. i had simular issues with the clutch, the pedal felt wierd like i was crushing a tennis ball, heavier than normal. I thought it was a master cylinder fault, but when i replaced that the slave cylinder failed pouring out all the brake fluid out the bell housing onto the road - resulting in no clutch at all.
-So im thinking should i have put a new clutch slave cylinder in EVERYTIME THE BOX IS REMOVED? or was i just unlucky?( bare in mind the cylinder only has done about 20k )
-i bought a brand that i believed were the manufacture for Fiat parts, but should i buy genuine Fiat product or does someone have a recomendation of a brand?

someone is coming to look at the van tomorrow to see if a bore scop can see the issue, eg is it leaking slightly or maybe a loose bolt...

 

[madwrx]

very late reply lol but the cost and time to take the box out makes a slave cylinder a must do after the box has been pulled,,in comparison the slave is a cheap part to leave out

 

[Marmitethecat]

very late reply lol but the cost and time to take the box out makes a slave cylinder a must do after the box has been pulled,,in comparison the slave is a cheap part to leave out

ive had a new genuine one fitted, but it seems on a long drive the pedal will sometimes not fully return.. im now wondering if i need to replace BOTH master and slave cylinder everytime the box is removed?

 

[madwrx]

this is often just air in the slave when bleeding ,,,its just a simple hydraulic push rod ,,,I would suspect other problems with brakes as well if the master was playing up ,,odd fault that one ,,at least the box wont need to come out for that though

 

[Communicator]

this is often just air in the slave when bleeding ,,,its just a simple hydraulic push rod ,,,I would suspect other problems with brakes as well if the master was playing up ,,odd fault that one ,,at least the box wont need to come out for that though

I always understood that the x250 had an annular slave cylinder, acting directly on the clutch release bearing.
The post makes more sense if master is substituted for slave.

Why should the brakes be affected, when the only common point is a shared reservoir with internal weirs?

 

[bugsymike]

I always understood that the x250 had an annular slave cylinder, acting directly on the clutch release bearing.
The post makes more sense if master is substituted for slave.

Why should the brakes be affected, when the only common point is a shared reservoir with internal weirs?

I agree 100% with @Communicator, when manufacturers saved money by having a dual purpose reservoir they realised that a clutch hydraulic failure must not interfere with brake operation, so in much the same as if a dual circuit brake master cylinder develops a fault in one circuit it doesn't drain the fluid from the other side. Some do this with a "weir" and some on the clutch side, position the fluid pipe for the clutch at a higher level in the reservoir so if for instance a clutch pipe split and lost all it's fluid no matter how much you pumped the clutch pedal it couldn't drain the fluid from the brake side.
So regarding accidents where people say their brakes failed, in point of fact in modern vehicles the brakes would still work, al be it in a limited fashion using only one circuit and with greater pedal travel. Anyone changing one brake cylinder and only bleeding the one wheel may notice that the brake pedal with bleeder open does not go right to the floor.
Unlike a 1950s Landrover I drove out to a breakdown in the 1970s which only had a single brake circuit as in one pipe from the brake master cylinder going to all wheels, hence when a pipe split I had the pleasure of driving up a kerb and halfway up a bank! I then did the repair on the customers vehicle and drove slowly back to the garage, fortunately with a good handbrake.

 

[Marmitethecat]

i can say this, when the clutch slave cylinder failed coming off the M6 motorway, it pxssed out all the brake fluid ONLY onthe top 3rd of the res. the brakes worked as normal,i drove the van aprox another 2 miles with no clutch, but fully working brakes.

 

[Marmitethecat]

but my post was about the clutch operation only, nothing to do with the brakes, only that the top half of the reservoir is for the clutch system