Intermittent clutch issues
Thread Starter
Pro
Joined: Oct 2020
Posts: 529
Likes: 197
From: Columbus, MS
Intermittent clutch issues
I've got a Tick master in my car. Recently it has become intermittent. Sometimes it will work as advertised and the car goes into gear no problem. Other times, it won't go into gear at all. Pedal is firm and feels normal. I've bled it and there's no evidence of leaking. Slave was replaced fairly recently, so I'm hoping it's not that.
Where should I start with this?
Where should I start with this?
Melting Slicks
Joined: Dec 2018
Posts: 2,647
Likes: 1,381
From: Orange County, CA
At this stage I'd drop the midpipes and clutch inspection cover, and watch the slave/pressure plate move when the pedal is pushed. The clutch disc should free up completely, and if not then it could point to a clutch issue. If it does then we can start looking at other things.
Thread Starter
Pro
Joined: Oct 2020
Posts: 529
Likes: 197
From: Columbus, MS
I dug into this more, and am just as stumped as ever. I inspected the slave and clutch area. No signs of leakage, and proper actuation was observed.
With the car on jack stands I tested the clutch. Pedal in, car in gear and the wheels don't move. Release the pedal and the wheels start to move. Push the pedal back in and the wheels stop. I held it for about 60 or more seconds, and still no movement with the wheels (indicating no pressure decay due to leak).
Then at an autocross yesterday I was right back to the intermittent bullshit. Sometimes it would work 100% perfectly, and other times it was like the clutch wasn't working at all. When it wouldn't work, I'd shut the car off, put it in gear, and restart and sometimes it would even jump like it was in gear with the clutch partially engaged!
I'm thinking maybe an air bubble in the master cylinder? I haven't had the system open in over a year, and the problem has started after quite a bit of problem-free operation.
With the car on jack stands I tested the clutch. Pedal in, car in gear and the wheels don't move. Release the pedal and the wheels start to move. Push the pedal back in and the wheels stop. I held it for about 60 or more seconds, and still no movement with the wheels (indicating no pressure decay due to leak).
Then at an autocross yesterday I was right back to the intermittent bullshit. Sometimes it would work 100% perfectly, and other times it was like the clutch wasn't working at all. When it wouldn't work, I'd shut the car off, put it in gear, and restart and sometimes it would even jump like it was in gear with the clutch partially engaged!
I'm thinking maybe an air bubble in the master cylinder? I haven't had the system open in over a year, and the problem has started after quite a bit of problem-free operation.
Safety Car
Joined: Mar 2017
Posts: 3,765
Likes: 938
From: Orlando Florida
The only bright spot I can offer is that when I’ve had this kind of problem it has been an internal leak with the master cylinder. Did you need the Tick? I worry that they can over extend the slave.
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Melting Slicks
Joined: Dec 2018
Posts: 2,647
Likes: 1,381
From: Orange County, CA
I dug into this more, and am just as stumped as ever. I inspected the slave and clutch area. No signs of leakage, and proper actuation was observed.
With the car on jack stands I tested the clutch. Pedal in, car in gear and the wheels don't move. Release the pedal and the wheels start to move. Push the pedal back in and the wheels stop. I held it for about 60 or more seconds, and still no movement with the wheels (indicating no pressure decay due to leak).
Then at an autocross yesterday I was right back to the intermittent bullshit. Sometimes it would work 100% perfectly, and other times it was like the clutch wasn't working at all. When it wouldn't work, I'd shut the car off, put it in gear, and restart and sometimes it would even jump like it was in gear with the clutch partially engaged!
I'm thinking maybe an air bubble in the master cylinder? I haven't had the system open in over a year, and the problem has started after quite a bit of problem-free operation.
With the car on jack stands I tested the clutch. Pedal in, car in gear and the wheels don't move. Release the pedal and the wheels start to move. Push the pedal back in and the wheels stop. I held it for about 60 or more seconds, and still no movement with the wheels (indicating no pressure decay due to leak).
Then at an autocross yesterday I was right back to the intermittent bullshit. Sometimes it would work 100% perfectly, and other times it was like the clutch wasn't working at all. When it wouldn't work, I'd shut the car off, put it in gear, and restart and sometimes it would even jump like it was in gear with the clutch partially engaged!
I'm thinking maybe an air bubble in the master cylinder? I haven't had the system open in over a year, and the problem has started after quite a bit of problem-free operation.
Thread Starter
Pro
Joined: Oct 2020
Posts: 529
Likes: 197
From: Columbus, MS
No. It has happened on cold starts, or after stopping after an autocross run, idling in the grid for a few minutes, and trying to move for my next run. I haven't established any kind of pattern. I can't reliably reproduce it, nor can I reliably correct it. I'm wondering if maybe there's an air bubble in the master that moves around? Is that a possibility?
Thread Starter
Pro
Joined: Oct 2020
Posts: 529
Likes: 197
From: Columbus, MS
I'm still dealing with this problem. Given that this car only sees the light of day for a few autocross or track events per year, it's been a really low priority.
I think it's an improperly shimmed slave cylinder. That REALLY sucks, because 1. it's my fault, and 2. I've gotta pull the driveline to fix it.
I'm going to throw a Tick slave at it when I've got it apart, and make sure that's the LAST time I need to **** around with the slave on this car ever again.
I think it's an improperly shimmed slave cylinder. That REALLY sucks, because 1. it's my fault, and 2. I've gotta pull the driveline to fix it.
I'm going to throw a Tick slave at it when I've got it apart, and make sure that's the LAST time I need to **** around with the slave on this car ever again.