Intermittent Clutch problem

JWGS

Member
Joined
Mar 19, 2019
Location
Essex UK
TDI
T30 shuttle
[FONT=&quot]I have a 2014 Volkswagen Transporter Shuttle T30 Se Lwb 140, 1968CC Diesel, 5DR, Manual.................to quote the formal name.

About 2 months ago I was at the tail end of a motorway journey having not braked or changed gear for perhaps 50 minutes, pretty well constant at 70mph as it was late at night. As my exit came up I was surprised to find my clutch pedal was on the floor and no travel left.

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[FONT=&quot]I lifted the pedal with my foot and found that I could pump the pedal a couple of times and get enough resistance back that I could operate the clutch and change gear. For the next 10 miles or so I was constantly having to lift the pedal and pump it to get some resistance back.[/FONT]
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[FONT=&quot]I parked at an intermediate destination for 15 minutes and returning to the minibus the pedal was up and usable to head home. All the way home, around 40 mintes and 30 miles I had the same issued with having to lift the pedal and re-prime. I dropped off a passenger and for the 4 windy road miles between our houses the pedal was perfect, as if there had never been a problem.

My local garage said it sounded like low fluid level and that the clutch take off is higher than the brake take off and it could just be low fluid and the fact the pedal came back after driving around bendy roads made so sense in that the fluid would have been thrown around and covered up a take off at a higher level.

Topping up the fluid seemed to cure the problem.....for a couple of weeks and it returned. The garage inspected it and of course it worked fine but they suggested the fluid was really dirty and perhaps had resulted in the hydraulic seals "flipping" inside out. I had not heard of this before so was happy to give it a try just having the fluid changed.

That seemed to work fine for around 6 weeks and then it came back at the start of a long run. Pedal flat to the floor and able to lift the pedal and pump it up till the point it could disengage the clutch. No fluid loss at all. The problem persisted on a motorway run and I was having to plan all gear changes by lifting the pedal first and pumping and lifting, pumping and lifting.

Where initially I thought that pumping whilst turning was most successful at re-priming, I now think it was probably lifting and pumping whilst occasionally braking was more effective. Since the brakes and the clutch share the same reservoir I guess there could be a chance that the pressures influence each other.

So I arrived at my destination (taking my Ice Hockey team to Bracknell for a game) and we played the game. At the end of the game I started to load the minibus and found that the pedal was perfect, no issues at all.

On the way home after a long constant speed spell on the motorway it dropped again and the normal routine of lift and pump.

Thats about as much detail as I can add. Is there anyone out there experienced the same and found what the heck is going on?

THe garage have it in and are planning on changing the master cylinder but I still want to know what the problem is!

Thanks!
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ToxicDoc

Veteran Member
Joined
Mar 1, 2018
Location
Virginia, US
TDI
2001 Jetta, S7, .216
sounds like a typical failing clutch master cylinder. to me. it doesn't always go from working perfect to not working at all. As the seals wear, they will have varying ability to hold the needed pressure.
 

JWGS

Member
Joined
Mar 19, 2019
Location
Essex UK
TDI
T30 shuttle
sounds like a typical failing clutch master cylinder. to me. it doesn't always go from working perfect to not working at all. As the seals wear, they will have varying ability to hold the needed pressure.



Thanks


And that is a reasonable expectation after 4 years and 120,000 miles?


John
 

JWGS

Member
Joined
Mar 19, 2019
Location
Essex UK
TDI
T30 shuttle
Thanks guys. Very helpful.

So the local garage changed the cluthch master cylinder on Friday. Seemed OK driving home :)

Used it for a 200 mile journey on Sunday. Within 5 miles of the start the pedal was starting to drop. It drops completely to the floor if I run at constant speed with no gear changes and braking (motorway driving) and seemed even more difficult to pump up. For most of the journey there I had just the last couple of inches at the bottom of travel but only if I lifted and pumps a bit.

Slower driving with some twists and turns and braking seemed to get it back a little.

After the Hockey game (4 hours ish) the pedla hadnt really come back, which happened last week. So just had enough active travel at the bottom of movement to be able to change gear.

Then around half way back, with around 50 miles to go, the full pedal came back. The surprising thing being this was whilst I was travelling around 70 constant, no gear changes no braking which were normally the idea conditions for the pedal to disappear.

Used the vehicle again today for around 2 hours of mixed driving and it has behaved perfectly no issues at all.

It seems too bizarre that someone wouldnt recognise this? Surely this cannot be the only time this weird behaviour has occured?

I am really getting the impression that being able to pump it up is either speed related somehow or braking related though I cant see how it can be.

Thanks for your continued thoughts and expertise!
 
Last edited:

JWGS

Member
Joined
Mar 19, 2019
Location
Essex UK
TDI
T30 shuttle
Thanks guys. Very helpful.

So the local garage changed the cluthch master cylinder on Friday. Seemed OK driving home :)

Used it for a 200 mile journey on Sunday. Within 5 miles of the start the pedal was starting to drop. It drops completely to the floor if I run at constant speed with no gear changes and braking (motorway driving) and seemed even more difficult to pump up. For most of the journey there I had just the last couple of inches at the bottom of travel but only if I lifted and pumps a bit.

Slower driving with some twists and turns and braking seemed to get it back a little.

After the Hockey game (4 hours ish) the pedla hadnt really come back, which happened last week. So just had enough active travel at the bottom of movement to be able to change gear.

Then around half way back, with around 50 miles to go, the full pedal came back. The surprising thing being this was whilst I was travelling around 70 constant, no gear changes no braking which were normally the idea conditions for the pedal to disappear.

Used the vehicle again today for around 2 hours of mixed driving and it has behaved perfectly no issues at all.

It seems too bizarre that someone wouldnt recognise this? Surely this cannot be the only time this weird behaviour has occured?

I am really getting the impression that being able to pump it up is either speed related somehow or braking related though I cant see how it can be.

Thanks for your continued thoughts and expertise!

Garage found some air in the hydraulics but I am unconvinced this is the issues and will use it over the next few days on some longer trips to see if I can lose the pedals again.
 

ToxicDoc

Veteran Member
Joined
Mar 1, 2018
Location
Virginia, US
TDI
2001 Jetta, S7, .216
I don't know what else would be wrong, unless you notice fluid loss, then I'd suspect a tiny leak in the line. A bent fork/pivot wouldn't act like this.
 

JWGS

Member
Joined
Mar 19, 2019
Location
Essex UK
TDI
T30 shuttle
I don't know what else would be wrong, unless you notice fluid loss, then I'd suspect a tiny leak in the line. A bent fork/pivot wouldn't act like this.

According to the garage who have studied this in detail from the underside there is no signs of even a slight fluid loss.

This is supported by no real loss of fluid in the reservoir and no need to top up.
 

ToxicDoc

Veteran Member
Joined
Mar 1, 2018
Location
Virginia, US
TDI
2001 Jetta, S7, .216
I'm not sure what else would do this. I don't think it's the throwout bearing or anything at the clutch itself, otherwise you would have clutch disengagement with the pedal down. I haven't looked at the actual pedal design. Could there be something strange at the pivot?
 

JWGS

Member
Joined
Mar 19, 2019
Location
Essex UK
TDI
T30 shuttle
So as an update I had another couple of weeks trouble free use, but bear in mind it gets used perhaps 2 or 3 times a week and perhaps 30 -50 miles when it is used.


Wednesday 17th April a trip of about 100 miles to Dover and heading out the pedal which had been hard up to its fullest point for 2 weeks was sitting a little lower and not quite so "hard" at the top end. No problems as usual changing gears etc.

On the way back the pedal starts to drop again and at times drops right to the floor and can only be brought back by lifting it by putting my foot under it and then pumping it to get a few inches of travel.....just enough to disengage gears.

So I send it back to the garage who say they had an identical fault with a brand new master cylinder on a Volkswagon car and then fitted an original VW master cylinder to replace a non original VW one they had fitted. So I find that the new master cylinder they had fitted was a non VW original and now they are fitting a genuine VW unit.

Having fitted the new cylinder I was just about to go and collect the minibus and they call me to tell me the pedla has dropped again and they need to check that it is bled OK and they dont have air in the system again causing the pedal to drop.

I dont think this makes the problem any more obvious does it?

Logically if two new master cylinders have not solved the problem then the only thing left is a new slave cylinder and I am being quited £1300 since a new clutch and flywheel are recommended.
 

ToxicDoc

Veteran Member
Joined
Mar 1, 2018
Location
Virginia, US
TDI
2001 Jetta, S7, .216
I wouldn't pay for a clutch if I only need a slave. That could've been changed at the time they replaced the master - on my truck for example the master and slave come assembled together as one part number.

I'm not sure how hard it is to reach on the Transporter, but on many vehicles the slave is relatively easy to access. You should be paying a fraction of that quoted price. If not, go elsewhere. Change the clutch only when you notice it's wearing out. That would be my approach
 

JWGS

Member
Joined
Mar 19, 2019
Location
Essex UK
TDI
T30 shuttle
On the transporter I understand that the slave is located inside the clutch housing so it is engine out to get inside and change the slave. By which time the effort to get in there on a 125,000 mile vehicle suggests that a clutch change would be sensible.


As an update it has now had a non VW master cylinder and an original VW master cylinder and in both cases after a couple of weeks working fine the issue returned.


After the VW master was installed it ran fine for a couple of weeks and then the pedal started to drop. This mostly happens when travelling at higher speed. On this occasion I had to keep using the vehicle for a couple of weeks due to a job that couldnt be delayed and for nearly 2 weeks I was driving a mixed journey of fast motorway and slower town trafic with lots of gear changes. Pumping the clutch almost constantly became second nature and my left leg is now similar to a wrestlers.


During this I did notice that the dropping pedal was more prevalent at higher speed and if I was struggling to pump up the pedal then a slight pressure on the brake pedal seemed to improve the ability to pump the clutch pedal back up. I also noticed that it I kept a very slight pressure on the clutch pedal (not enought to slip the clutch of course) that the pedal didnt drop at all.

I had it booked in to have another clutch fluid bleed to see if air had got in again but a couple of days before it was due to go in the problem stopped. It still went to the garage and they said they couldnt find anything and that the pedal had behaved all the time they had it. So now from having to constantly pump the pedal I now have a perfectly reliable clutch and in between times absolutely nothing has been done to the vehicle!!!!!!

This is the first time that it has "self-healed". All previous times when the clutch started to play up it only stopped after it had had attention by way of being bled or having a new master cylinder.

I am not sure if this is a possibility but can the air above the fluid in the master cylinder be under "vacuum" if a vent or something similar is blocked? Is there any way that this "vacuum" could result in air being drawn in past the slave cylinder seals and the mechanical vibration and movement at the clutch end can encourage the seals to allow air through the seals? I believe the hydraulic seals are normally angled so that fluid pressure forces them to seal against the walls of the piston and cylinder even harder but that would suggest that a negative pressure may draw the seals back from the cylinder and allow air back in.

I am thinking this way due to the fact that keeping some minor pressure in the system has prevented the pedal dropping and I am assuming that the pedal dropping is due to air somehow getting into the slave. So by keeping some positive pressure on the right side of the seal has prevented the air ingress that seems to be the problem.
 

Denny77

New member
Joined
Nov 16, 2023
Location
Herts
TDI
T3
On the transporter I understand that the slave is located inside the clutch housing so it is engine out to get inside and change the slave. By which time the effort to get in there on a 125,000 mile vehicle suggests that a clutch change would be sensible.


As an update it has now had a non VW master cylinder and an original VW master cylinder and in both cases after a couple of weeks working fine the issue returned.


After the VW master was installed it ran fine for a couple of weeks and then the pedal started to drop. This mostly happens when travelling at higher speed. On this occasion I had to keep using the vehicle for a couple of weeks due to a job that couldnt be delayed and for nearly 2 weeks I was driving a mixed journey of fast motorway and slower town trafic with lots of gear changes. Pumping the clutch almost constantly became second nature and my left leg is now similar to a wrestlers.


During this I did notice that the dropping pedal was more prevalent at higher speed and if I was struggling to pump up the pedal then a slight pressure on the brake pedal seemed to improve the ability to pump the clutch pedal back up. I also noticed that it I kept a very slight pressure on the clutch pedal (not enought to slip the clutch of course) that the pedal didnt drop at all.

I had it booked in to have another clutch fluid bleed to see if air had got in again but a couple of days before it was due to go in the problem stopped. It still went to the garage and they said they couldnt find anything and that the pedal had behaved all the time they had it. So now from having to constantly pump the pedal I now have a perfectly reliable clutch and in between times absolutely nothing has been done to the vehicle!!!!!!

This is the first time that it has "self-healed". All previous times when the clutch started to play up it only stopped after it had had attention by way of being bled or having a new master cylinder.

I am not sure if this is a possibility but can the air above the fluid in the master cylinder be under "vacuum" if a vent or something similar is blocked? Is there any way that this "vacuum" could result in air being drawn in past the slave cylinder seals and the mechanical vibration and movement at the clutch end can encourage the seals to allow air through the seals? I believe the hydraulic seals are normally angled so that fluid pressure forces them to seal against the walls of the piston and cylinder even harder but that would suggest that a negative pressure may draw the seals back from the cylinder and allow air back in.

I am thinking this way due to the fact that keeping some minor pressure in the system has prevented the pedal dropping and I am assuming that the pedal dropping is due to air somehow getting into the slave. So by keeping some positive pressure on the right side of the seal has prevented the air ingress that seems to be the problem.
have the exact same problem with my t5, everything you say is happening to me, plus I now have a intermittent sticking break, someone did mention it could be a vacuum related problem but I’m struggling to get to the bottom of it, did you ever figure it out?
 
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