Sponsored

Strange Clutch behavior (not Mustang)

HoosierDaddy

Well-Known Member
Joined
Jan 2, 2016
Threads
232
Messages
3,373
Reaction score
7,131
Location
Winchestertonfieldville (ok, Scottsdale), AZ
First Name
Randy
Vehicle(s)
2016 GT Premium PP
We also have a 2013 ATS M6. Nobody on the Cadillac forums where I am a mod have had this happen, but almost all of them drive auto trans models. So I thought I would ask here in case its something that might happen with other clutch systems and some one here might have an idea.

The ATS is my wife's daily driver, a birthday present for her in 2013.

I drove it for an errand Friday because it was warmed up at the time. When I got in the car to return home, the clutch pedal didn't return after starting the car. I tried to pull it up with my toes but it wouldn't budge. There was maybe an inch of travel. When pressed to the floor it did not fully disengage so the trans didn't want to go into gear. I could start the car with it in gear and the pedal down but the car would creep just slightly. Not enough drag to even cause any RPM drop when holding the car on the brake. But when released (and moved up an inch), it fully engaged. It was like the clutch had almost a full range of motion (just barely dragging when depressed) but over an inch of pedal travel instead of the normal full range of travel

So I drove it home, turning it off at every stop and restarting in first. Since engagement was over such a short distance, I had to let it out much slower to keep from stalling. I also rev-matched for shifts just in case.

When I got home I turned it off and reached down and grabbed the pedal with my hand and yanked on it in all directions. After a few cycles of that, it suddenly popped back up. I think it sprang free from a mostly sideways yank. I drove the car around the neighborhood and the clutch worked perfectly.

Since its my wife's daily driver, I don't want her to get stranded somewhere. But before taking it into Cadillac, I thought I'd see if any of you have an idea what could have happened.
Sponsored

 

tom_sprecher

Living Race Car Free
Joined
Jul 2, 2016
Threads
30
Messages
1,224
Reaction score
466
Location
Marietta, GA
Vehicle(s)
2016 GT Premium PP 6MT Race Red
The clutch pedal in my Mustang will do that except I can pull it back up with my toes. It only happens occasionally and once pulled back up it work fine for months. Maybe it a sticky one way valve in the master.
 
OP
OP
HoosierDaddy

HoosierDaddy

Well-Known Member
Joined
Jan 2, 2016
Threads
232
Messages
3,373
Reaction score
7,131
Location
Winchestertonfieldville (ok, Scottsdale), AZ
First Name
Randy
Vehicle(s)
2016 GT Premium PP
Thanks.
 

Anthony 05 GT

Well-Known Member
Joined
Jun 4, 2015
Threads
21
Messages
1,453
Reaction score
490
Location
Northern Harford County Maryland
Vehicle(s)
2005 Mustang GT, 2015 Mustang GT Premium
I would bet it's the clutch master cylinder too.
 
OP
OP
HoosierDaddy

HoosierDaddy

Well-Known Member
Joined
Jan 2, 2016
Threads
232
Messages
3,373
Reaction score
7,131
Location
Winchestertonfieldville (ok, Scottsdale), AZ
First Name
Randy
Vehicle(s)
2016 GT Premium PP
I would bet it's the clutch master cylinder too.
Double checking. Could a master cylinder problem make it impossible to pull the pedal back UP by hand but allow it to return to normal after a side ways yank on the pedal? Or refuse to budge at all with several yanks up and suddenly pull up easily on the next yank?

FWIW I have been driving it and having my wife drive the Mustang and it has been perfect for the last 5 days which makes it a total crap shoot to take it to the dealer outside the factory warranty.
 

Anthony 05 GT

Well-Known Member
Joined
Jun 4, 2015
Threads
21
Messages
1,453
Reaction score
490
Location
Northern Harford County Maryland
Vehicle(s)
2005 Mustang GT, 2015 Mustang GT Premium
It could bind if the piston gets cocked inside the bore. I've never experienced that, but I repair electric forklifts for a living and deal with all types of cylinders. I guess I would say it's possible. I would also suspect maybe a bind in the pedal box. Basically, all it is (on most cars) is a plastic pedal box that bolts to the firewall with a linkage rod from the pedal's upper area that enters a cylinder which contains a piston and seals that push hydraulic fluid (usually brake fluid in cars) through a small line that goes down to the bell housing to the slave cylinder which also contains a piston and seals.

If the slave cylinder was binding up I could see the pedal not coming back up too because the sealed system works together in kind of a vacuum for lack of better words. Kind of like if you were to suck a popsicle into your mouth it's kind of hard to pull out unless you allow the pressure to reverse. With hydraulics the piston in each cylinder move together because of the fluid which does not compress like air does. The pedal very well could have been fighting your pulling if the slave cylinder was binding....in theory.
Sponsored

 
 




Top