Clutch Pedal Feel

[WIL35]

Have looked through the search items and could not find a similar symptom: Had difficulty engaging first the other day, but managed eventually, so decided to bleed the clutch fluid. Fluid level was fine and there doesn't appear to be any leaks in the footwell or under the car.

Ended up changing the fluid to Dot 5.1, usual black 'soot' in the old fluid. Started engine and all the gears engaged fine. However, if I just rest my foot on the pedal quite gently the pedal moves to the floor without any resistance. If I use it normally it's fine.

Could there be a leak within the master cylinder?

[Onzlouk]

Hold on to your seat.... I lost all of my gears a couple of weeks ago, i managed to get home ok in second as i could engage with the car turned off. I, like you got home and bled the fluid, replaced with 5.1 and all was well although the slight spongyness was still there, cue the 12k service a week later....it ended up having a new master and slave cylinder. The slave is inside the gearbox and when this was out and the clutch was inspected it was found that there were some springs broken off, so that was replaced too. Now, the clutch and whole car feel fantastic, although im now busking to feed my children.
As jensenA said to me, ill keep my fingers crossed for you.

[BLUETHUNDER]

If you are having trouble getting gears,then i would think that some of the fingers are broken.With the pedal sinking,then that points to the slave.Seems like the fluid is by-passing the seals.You could have a combo of the two.

Edited by BLUETHUNDER on Tuesday 24th June 09:44

[FarmyardPants]

For the pedal to sink the fluid must be getting past the seals (either master or slave, more likely the latter). If you put the clutch to the floor and engage first gear, does the car start to move when the pedal is still on the floor? If not, you might have a scored cylinder lining (but not scored at the point where the pistons are at full travel, if you see what I mean).

[WIL35]

I will try it again tonight, when I started the engine after the fluid change and tried slotting through the gears it felt normal, ie pushing clutch quite quickly felt like usual resistance. It was only when gently resting my foot on the clutch that there was no resistance.

I do see what you mean about some of the bore being scored. I suppose the logical thing to do would be to change the master cylinder and if that doesn't fix it, it will be slave AND clutch time!! (Have to dig out Madmarks guide! I've been through the process lots of times in my head).

[FarmyardPants]

I suppose if the pedal sinks only under light pressure, your seals and bores are probably fine, or not broken at least. The seals need a bit of pressure differential to force them outwards and make a good seal, especially if they've lost some of their flexibility. If your fingers are broken then the clutch won't be pushing back so hard, so a slow push may allow the fluid through due to lower pressure difference. It's normal, and cheap, to refresh the slave seals whilst the clutch is out anyway...

[trackcar]

the problem is likely to be the recuperating valve in the end of the master cylinder.. gives exactly the symptoms you describe.

The recuperating valve is there to allow fluid into teh hydraulic pressure side of the system should you lose fluid etc .. the recuperating valve must be closed/sealed for the system to generate pressure .. it takes the form of a small cup type rubber seal right at the end of the master cylinder bore.

It's likely that your master cylinder is ok and just needs a reseal kit fitted, or if you dismantle it to fit the kit and find it scored internally it needs replacement.

[WIL35]

That all makes sense. Presumably if I take the cap off of the fluid reservoir and get someone to press the pedal gently, if the level in the reservoir goes up then it would indicate that it is the valve allowing fluid back into the reservoir, which it isn't supposed to do.

[Byker28i]

I had my pedel sink to the floor during london thunder and assumed the worse, but rapid pumping got it back. It turned out to be dirty manky oil which absorbed the heat from the cats? and failed. Once I got out of the jammed up London traffic and the car cooled down it was back to normal.

I flushed completely through with a few litres of dot 5.1 and it's been fine since.

[alderley]

Byker28i said:

I flushed completely through with a few litres of dot 5.1 and it's been fine since.

A few litres!!!!!It is simpler to 1. use a syringe to empty out your fluid reservoir, 2. clean out reservoir with some fresh fluid and 3. Top up and bleed. This way you soon have clean fluid going through your pipework instead of diluted black gunge. I change my clutch fluid every 2k miles.

[cupra20v.t]

any pictures of a master cylinder either in situ or off the car, and especially this recuperating valve