What on earth’s happened to my clutch pedal?!
Discussion
06 Vantage.....Since yesterday, only when cold (so that’s three starts from cold now,) my clutch pedal has been very floppy/light (I.e no pressure for first half of travel) and most of the time sticks down. Has to be brought up with the back of my foot.
I’d say this is about 2 out of 3 of gear changes, and all the biting/actuating going on right down the end of the pedal travel, and just floppiness/zero resistance for the first half. Stalling and jerkiness galore.
Then every third or so change, there’s pressure through the entire pedal travel and clutch is biting where it should (nearer the top.)
After it’s up to temp and a few miles, it’s goes back to normal and behaves itself perfectly, no issues at all.
New clutch/flywheel/slave cylinder earlier this year 3k miles ago.
I should add, this happened after changing brakes this weekend and had the reservoir cap off, which leaked a small amount when I first drove it but is now tightened properly. Not related I presume?
Any advice gratefully received
I’d say this is about 2 out of 3 of gear changes, and all the biting/actuating going on right down the end of the pedal travel, and just floppiness/zero resistance for the first half. Stalling and jerkiness galore.
Then every third or so change, there’s pressure through the entire pedal travel and clutch is biting where it should (nearer the top.)
After it’s up to temp and a few miles, it’s goes back to normal and behaves itself perfectly, no issues at all.
New clutch/flywheel/slave cylinder earlier this year 3k miles ago.
I should add, this happened after changing brakes this weekend and had the reservoir cap off, which leaked a small amount when I first drove it but is now tightened properly. Not related I presume?
Any advice gratefully received
you have air in the system, if you pump the pedal 5 -10 times you probably wont have the problem. You can try pumping the pedal up, then leaving it about 50% compressed over night, bit of wood between the seat and the pedal which may well displace the air.
Failing that it needs bleeding through properly, if its still a pain then you had better hope the issue is the master clyinder, not the slave.....
Failing that it needs bleeding through properly, if its still a pain then you had better hope the issue is the master clyinder, not the slave.....
IainWhy said:
you have air in the system, if you pump the pedal 5 -10 times you probably wont have the problem. You can try pumping the pedal up, then leaving it about 50% compressed over night, bit of wood between the seat and the pedal which may well displace the air.
Failing that it needs bleeding through properly, if its still a pain then you had better hope the issue is the master clyinder, not the slave.....
Nice one - yes it does seem to get better when still cold if I pump pedal a few times.... but then goes back to loose again.... until warm! Will try the method you describe Failing that it needs bleeding through properly, if its still a pain then you had better hope the issue is the master clyinder, not the slave.....
How does air get into the previously perfectly OK system? Just one of those things occasionally?
Krhuangbin said:
How does air get into the previously perfectly OK system? Just one of those things occasionally?
No, not really - air is getting in from somewhere it shouldn't be (on any hydraulic system, not just this). You may improve it for a while, but unless it's been drained and/or bled recently, and not fully, then air is getting in through a leaking seal or hose, and the clock is ticking until that particular item gives out.Normally I’d say the master cylinder needs replacing but given it’s happened just after you’ve changed the brakes, have you got the brake fluid reservoir (which is also the clutch fluid reservoir) filled with the correct amount of fluid? If so then I would bleed the clutch and see if that fixes the issue.
Will check brake fluid reservoir in the morning.
I did the brakes, didn’t tighten the reservoir cap properly (whoops) and took it for a bedding in session. Checked the engine bay when back and saw a slight leak around the cap and down into the engine bay..... but the level was still between min and max. Cleaned up and tightened it fully (no further leaks anymore) and now have the clutch issue. So
Probably that then, and needs bleeding?
I did the brakes, didn’t tighten the reservoir cap properly (whoops) and took it for a bedding in session. Checked the engine bay when back and saw a slight leak around the cap and down into the engine bay..... but the level was still between min and max. Cleaned up and tightened it fully (no further leaks anymore) and now have the clutch issue. So
Probably that then, and needs bleeding?
Apols, I didn't read your OP fully enough.
Yes, topping up and bleeding is definitely your first port of call, hopefully that will address it. When you left the cap off, were you braking/accelerating hard at times, maybe to start bedding the new brakes in? Could have caused a momentary "slop' which let a bit of air in?
If that's the case then you may need to look at bleeding the brakes as well?
Notwithstanding being an AM owner, I haven't looked into the config of the hydraulics (brakes/clutch) so I'm speaking from general auto engineering principles, but reading between the lines of what others have posted above, I think we're on the right track.
Yes, topping up and bleeding is definitely your first port of call, hopefully that will address it. When you left the cap off, were you braking/accelerating hard at times, maybe to start bedding the new brakes in? Could have caused a momentary "slop' which let a bit of air in?
If that's the case then you may need to look at bleeding the brakes as well?
Notwithstanding being an AM owner, I haven't looked into the config of the hydraulics (brakes/clutch) so I'm speaking from general auto engineering principles, but reading between the lines of what others have posted above, I think we're on the right track.
It can just happen, so i wouldn't panic. Try leaving it compressed, this will allow any air for work back up into the reservoir over time.
The problem with bleeding these is that the design of the concentric means you are trying to push air through fluid downwards, which is akin to kicking jelly up hill so they can be tricky to bleed.
Most probably when you bled the brakes you let the fluid level get a bit too low and a little air has got into the clutch line when you topped it up. its not a major drama.
Compress it, leave it and the air will work its way back to the reservoir, they are not air tight so its nothing to do with a loose cap.
I had this issue on mine after i changed the clutch and a combination of just using the car and leaving it compressed resolved it, otherwise your into pressure bleeding really and that can be a faff in its own right.
The problem with bleeding these is that the design of the concentric means you are trying to push air through fluid downwards, which is akin to kicking jelly up hill so they can be tricky to bleed.
Most probably when you bled the brakes you let the fluid level get a bit too low and a little air has got into the clutch line when you topped it up. its not a major drama.
Compress it, leave it and the air will work its way back to the reservoir, they are not air tight so its nothing to do with a loose cap.
I had this issue on mine after i changed the clutch and a combination of just using the car and leaving it compressed resolved it, otherwise your into pressure bleeding really and that can be a faff in its own right.
Krhuangbin said:
Just been out in it this afternoon, and the clutch was good as gold, no issues at all from cold or at any point. Weird!
Will leave the pedal half pressed overnight to be sure, but seems to be ok now
Yea as said, just general use will generally displace air and as its the lowest point in the clutch hydraulics they will to extent self bleed, see how it goes. Will leave the pedal half pressed overnight to be sure, but seems to be ok now
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