Gear selection issues....clutch slave cylinder?

[Nessy]

Right,
Experiencing a few issues with my trusty A4 TDI and would appreciate your advice!
Car has 248k miles under its belt, at 192k miles it had a replacement s/h gearbox and new dual mass flywheel /clutch kit and release bearing, all Genuine Parts fitted.
Whilst parking the car up the other day with windows and sunroof open I heard a distinct noise from under the bonnet when depressing the clutch that sounded like a rattling release bearing....oh no!
I thought that as the car has done 55k miles since the work it would need some attention in the not too distant future....
Fast forward to last night and on my way to work I come to my motorway exit and as I join a roundabout I go to change from 5th to 4th gear only to find I have absolutely no gears!
The lever will only stay in the neutral plane but will not go anywhere else!
I'm forced to come to a halt in the middle of a massive roundabout (!!!) with gear selection impossible!
I try revving the engine and then try to engage gears-no luck.
Switching the engine off and on again brings no improvement.
Forcing the gear stick into the direction of 1st with clutch pedal fully depressed elicits a very nasty grinding noise!
The clutch pedal feels the same as it has always done , there is no extra travel or anything like that etc.
After about 5 mins of trying everything I can think of and on the verge of ringing the RAC I press the clutch pedal, try selecting 1st and in she goes!
Suddenly I have all gears again!
I limp the remaining few miles to work and begin to worry about the journey home this morning.
This morning the car performed OK, although on the few occasions I had to go from 2nd to 1st it wasn't as easy as it should have been?
This morning there is no noise when the clutch is depressed, so could a clutch release bearing create intermittent noise?
One fact that might be relevant is that a few times over the last month (I do 80 miles a day btw and this has happened about once a week) I have found that I've needed to literally yank the gearstick out of its position to change gear eg from 5th to 4th...
I'm beginning to suspect either the pedal master cylinder or the clutch slave cylinder but would appreciate your input.
Sorry for the essay but wanted to include all the details, thanks!

 

[aragorn]

seems like a fair assessment, could also be the release bearing or clutch fork.

As a little tip if it happens again and your stuck in the middle of a roundabout:

Turn the engine off, put the gearbox into first, and start the car. It'll jolt and judder but it will start in gear and allow you to drive off and get somewhere more safe to figure out whats going on!! I've driven 5 miles home in an old Astra after my clutch cable snapped using just that method, rev matching every shift so it'll change without the clutch and turning the engine off and starting in gear whenever i had to stop! Not fun, but meant i wasnt stranded!

When you were pressing the clutch and it wasnt working, did the clutch feel normal, or did it just hit the floor with no resistance? If it was a hydraulic failure, i'd expect the clutch to just drop with no resistance/feedback.

 

[Nessy]

seems like a fair assessment, could also be the release bearing or clutch fork.

As a little tip if it happens again and your stuck in the middle of a roundabout:

Turn the engine off, put the gearbox into first, and start the car. It'll jolt and judder but it will start in gear and allow you to drive off and get somewhere more safe to figure out whats going on!! I've driven 5 miles home in an old Astra after my clutch cable snapped using just that method, rev matching every shift so it'll change without the clutch and turning the engine off and starting in gear whenever i had to stop! Not fun, but meant i wasnt stranded!

When you were pressing the clutch and it wasnt working, did the clutch feel normal, or did it just hit the floor with no resistance? If it was a hydraulic failure, i'd expect the clutch to just drop with no resistance/feedback.

Thanks for the tip!
The clutch pedal felt the same as it has always done, definitely no difference in resistance etc.
I replaced the NSR caliper /flexy hose last week as the old one was seized/sticking and only bled that part of the circuit using a 1 man bleeder kit.
When I went to top up the brake fluid it was below the minimum level (the driver information system display began beeping at me), could this have sucked air into the clutch side?
I doubt if it could, just mention it in case it has some bearing?

I'm really hoping it is a hydraulic/bleeding issue , the release bearing or clutch fork means hassle and lots of £££££.

Any ideas how I can narrow it down?
I'm not using the A4 now as have access to another car for as long as I need, but am going to miss the TDI economy ...

Cheers

 

[aragorn]

hmm seems very odd that there was no change in pedal feel.

I wonder if you can get an endoscope and peer inside the bellhousing to see if theres anything going on in there?

If your concerned about air, then just bleed the clutch thru. It shouldnt have got any air into it though. Probably worth bleeding the clutch anyway to get some fresh fluid into it!

 

[Nessy]

hmm seems very odd that there was no change in pedal feel.

I wonder if you can get an endoscope and peer inside the bellhousing to see if theres anything going on in there?

If your concerned about air, then just bleed the clutch thru. It shouldnt have got any air into it though. Probably worth bleeding the clutch anyway to get some fresh fluid into it!

Thanks, will bleed it as soon as I get a day off.....
Definitely no change in pedal feel, its got me stumped.
The more I think the more I realise it must be a clutch disengagement issue for whatever reason.
Don't understand though how the release bearing can be seemingly noisy one day and OK the next?