Dragging clutch - 2008 1.9 TDi Manual

[GTEye]

For the last week or so, the clutch on our 2008 1.9 TDi has not been releasing fully - i.e difficult to engage gears, especially reverse. Sometimes it is intermittent, but it does seem to be getting worse. My thoughts are a hydraulic problem, but I am not sure where to start looking, as the clutch m/cylinder appears well hidden under the dash. The other possibility is perhaps the clutch plate sticking on the splines, but again hard to check. The car has done 208,000kms, but is very original and appears well serviced, and there are no visible leaks. The clutch feel is good (i.e. no slipping, etc.) I'm wondering it anyone has had a similar problem, and suggestions for possible checks/fixes? Thanks in advance, John

[JTop]

Before you do anything, attempt to realign the shifter. The rubber bushings give way/or the plastic slips and you aren't moving the shift column how it needs for each gear.

If that doesn't solve it. then...
Put it simply. The clutch is not fully disengaging from the flywheel, which means your gearbox is in constant motion.
Which makes it awfully difficult to engage reverse without the gearbox side halting to a complete stop.

Bleed the clutch line, if nothing good comes from it, it might be the slave giving way, so disconnect it and check for wear and condition
OR worst case, bent clutch fork... box off to get that sorted really...

Hope this helps mate

[GTEye]

Thanks JTop for your response.
Think I can dismiss shifter issues, because all gears select properly and smoothly once I can get the clutch to disengage.

The second part of your answer describes the problem fully, but the puzzle is that it is a bit intermittent - maybe one time in ten clutch works correctly and reverse doesn't crunch, but most times clutch is dragging. I have removed the slave cylinder from the flywheel housing and it looks fine, no wear or hydraulic leaks. looking under the dash behind the clutch pedal again looks fine, clean and dry.
I could try replacing the slave cylinder (g'box end), but the master cyl. under the pedal looks to be a pain to replace(

I don't think it is bent clutch fork, as sometimes it works OK. My other thought is the clutch plate sticking on the gearbox spline, but there's no sign of oil/grease in there.

Any suggestions for bleeeding the system - the only bleed valve seems at the slave cylinder?
Thanks again for your thoughts, and I will keep investigating, and am still hoping someone with a similar problem may be able to help.

[sambb]

mate my clutch is exactly the same. When its cold I have to really feel for the meshing before I can get it to go into first and the clucth first engages a smidge off the floor. I checked the master for leaks into the cabin side -ok, did the same at the slave end - ok no leaks, vacuum bled the clutch line until I got a cleaner colour. I was expecting air bubbles to be there and be the cause but was disappointed to find no air. I used a pump up vacuum bleeder to do the job and yeah the nipple is down on the slave so battery and airbox have to come out. The bleed screw is plastic so make sure you have a proper 12mm open ended ring spanner or you could easily strip it. It takes ALOT of turns before it cracks too which will twist up your flexible line to the bleeder bottle and annoy the hell out of you. So like Jan said that leaves bent release fork as probably the most likely for me. Otherwise the clutch clamps up fine, no slip.
Once I ran through all that I decided to get all the bits together for a clutch swap. For me that means a gearbox swap as I've had a spare rebuilt box ready to go for quite a while. Western clutch is balancing the pressure plate/clutch and single mass flywheel and setting the clutch travel as we speak, I've got a rear main seal on the way, driveshaft flange gaskets etc etc. My spare fork has been plated/welded up so that fork bending is not an issue in the future. I'm going to drive mine until I cant anymore and then do a complete swap over when the time comes.
I hope for your sake it s full of air and you're good to go afterwards.

[sambb]

If you do end up doing the clutch, the best path is to do a conversion from dual to single mass flywheel (aftermarket or G60?) , VW VR6 clucth/PP. Mine was an ECS stage 1 kit (steel lightened fly with the VR6 bits) and it got years of abuse on the road and track and the pedal is actually lighter than what you've had and engages nice and high!!

[JTop]

Is it only happening when the engine/trans box are hot? I also keep thinking the fluid for these boxes isn't correct due to the fact once warm, synchros aren't as happy? I've sometimes got 3rd gear crunching for every upshift only after driving 20+ minutes and even after swapping fluids, it hasn't aided in fixing it. Yeah... I need to sort this out again :/
But anyway

The more Polo's I've owned, I've gotten to the same conclusion:
The clutch+brake system is perfect on paper
Realistically can be troublesome and cause more damage WHEN treated like a racecar

I've pretty much clunked every single Polo going into reverse, althought I MIGHT by accident have left the tiniest bit of clutch left depressed to cause it(I smash that clutch in nowadays just to be sure it's fully disengaged). My brothers Polo, although you have the clutch to the floor will do it no matter. Absolutely no saving that car hahaha
Super easy for this to occur, albeit saving a second or two before engaging into reverse usually saves it from happening.

But.. I can say this. The ones that have had a hard life, are more inclined to do it than the ones that have not. EVEN with a fully pressed clutch.. and the only conclusion I've come to is the fork must be warped/crooked*.
Slamming gears each time and not fully pressing the clutch in on the shift can also start causing these problems. BUT I must say that the plastic/rubber slave and master, plus an overly abused release fork combo aren't the best when going consistently hard.

*Only because the masters and booster in theory should have nothing wrong with them if they can push fluid. But with age, I would attest the booster to start causing the spongey feel on the brake pedal, probably due to the fact the internal diaphragm might be overly worn and have started collapsing or not returning to its intended position? I'd need to split one in half to get a better explanation, I'm just mentally correlating this to how boiler expansion tanks filled with an inert gas, usually n2 which die randomly, causing boilers to not work at all. And applying shock absorber theory to it hahahahaha, probably not even close to how it actually functions, but same same, maybe different mechanical components used. ANYWAY
Also having the plastic clutch master being pressed and depressed a tens of thousands of times, you'd expect some sort of wear on the item. There has to be... Nothing lasts forever

I have one Polo from Ben(teamshaw) which defined all odds, it's got a strong pedal and clutch given it has 231,000kms on it. New DBA rotors and pads too!!! Again, it all depends on usage and I know it's done more highway kilometres than city driving and although it has that mileage, hasn't been treated as badly as the rest of these cars have.
Anyway, vacuum bleed each corner, working the brake pedal and fill the reservoir each time until you have a strong pedal. Then do the clutch last, (Sam, ain't the nipples metal? and 11mm? that's what I've always been using!!!!), again pumping the clutch pedal multiple times(to pressurise the line) before releasing fluid at the slave cylinder which is the only place you can do it at. With it all, try to aim to release enough fluid on the last go so that the reservoir reaches the max level and stays shut. Attempting to keep the entire system under a bit of vaccum.
VW manual states the pressures you should receive on the clutch bleed, I forget if there is a value on the brake bleeds. Can also cycle the ABS module whilst doing the bleed so that too releases all the air in its system.

[sambb]

11. 12mm I’m still learning to count. Probably is 11mm. Yeah I think the bleed screw on the clutch slave was plastic on mine. Black and very soft whatever it was. I think when you do the clutch line bleed you need to pull a lot of fluid out at the slave. It’d be pretty easy fir any air in the system to run straight up to the clutch master and then get trapped there.

[GTEye]

Many thanks JTop and sambb for all your input and thoughts - exactly what I was hoping for in the post. However problem is not yet sorted, and with our current lock-downs it may not be for a while yet ;-((

I will first do a thorough bleed of the system, I take it you are meaning from the brakes first then the clutch. I will probably have to get a pressure bleeder, which I don't have atm, but some mates should be able to help when we can travel more than 5kms again.

I had thought of changing gearbox oil, but it is very clean and the gearshift is/was very smooth (when the clutch disengages properly). Clutch problem appears whether the car is hot or cold.
Until this problem occurred about 10 days ago, clutch and gearbox action was great, and even now clutch pedal height (take-up point) seems about normal.

Still hoping the problem can be solved without gearbox removal, as I am a bit over that sort of work. I will press on with bleeding and checking, and let you know the result.

I believe the clutch hydraulic system on our 9N3 (1.9 TDi) is unique to Mk 4 Golf, Bora and early new Beetle, so experience of this problem is a bit more limited.I wish it was as simple as the cable clutch system on my Mk 1 and Mk 2 Golfs.

[sambb]

the clutch line comes seperately on a rubber hose straight off the brake master cylinder. The clucth master cylinder is half way down the firewall fed by this hose. From there it runs down around to the gearbox. Becuae its a seperate system to the brake system (except for sharing the same reservoir) you can just bleed the slave on the gearbox. It wont be affected by the rest of the brakes. I havent had a stock battery in the car for years. I'm pretty sure though that the battery can remain in the car but the airbox will have to come out. Then its just the usual case of not letting the fluid level in the brake master cyl reservoir dropping below the clutch lines intake while you pressurise/vaccum. A second party to give the clucth pedal a few pumps wouldnt hurt either. Hopefully its full of air and you'll be good to go afterwards.

[GTEye]

Great advice, thanks sambb. I will give it a good go, and let you know how it works. I may have to stock up on hydraulic fluid though, as soon as I can get out to a store again. As its a seperate system to the brakes, then can I get away without a power bleeder?

Yes I can get to the bleeder valve with the battery still in, just the air cleaner box removed.