Clutch pedal lost pressure behind it.

[Oneofakinder]

Pulled into a customers driveway earlier today, pushed the clutch and it went straight to the floor. Did my work and came back out, still has no pressure. I managed to get it home (30 miles), by starting off in first then turning the engine over. I checked all the lines, clutch master cylinder, slave cylinder, no oil anywhere, reservoir is full and the brakes work fine. When I have someone press the clutch, I can watch the fork move like it's supposed to, but you can't feel any pressure behind it at the pedal. Any suggestions to try or check before I tear into it?

Thanks,
Trevor.

 

[dacquesta1]

sounds like the throw out bearing isnt connected to the release fork.

 

[Oneofakinder]

I just checked again. I bled the slave cylinder thinking that might help. While doing that, the clutch fork only moved about 1/4 of an inch, so it's not even pushing the fork in all the way.

 

[dacquesta1]

maybe a bad clutch master cylinder? take the slave cylinder off of the release fork and see if there is any rust/grime and clean it and put a little grease on the slave cylinder side of the rod. hopefully its either the master or slave cylinder and not the actual throw out bearing getting caught up on something.

edit: your not losing any brake fluid when you pump the hell out of the clutch? like 50+ times and no fluid drop right?

 

[Protege03ak46]

Sounds like a bad seal in either the slave or master. Hope its not the master, talk about painful...

 

[Oneofakinder]

could be either one. I'll check in the daylight tomorrow. None of the seals are leaking on the master or slave cylinder(firewall, under the dash, or down at the slave cylinder). Either way, none of the parts houses stock either of them so tuesday is the soonest I can get one.

 

[dacquesta1]

master cylinder isnt too hard to replace...just a bad angle squeezing in there by the pedals to get the nut on the inside of the car.

 

[Protege03ak46]

could be either one. I'll check in the daylight tomorrow. None of the seals are leaking on the master or slave cylinder(firewall, under the dash, or down at the slave cylinder). Either way, none of the parts houses stock either of them so tuesday is the soonest I can get one.

Internal seals wont leak...

 

[Oneofakinder]

Ok, this morning I replaced the clutch master cylinder and rebled the system. The slave cylinder doesn't move any farther than it did. So I paid for a slave cylinder and it will be here monday morning. We'll see what happens from there.

 

[Oneofakinder]

So the part Napa ordered me was for a 1.6L. Different mounting. They can't even get the slave cylinder I need, it's not in their system. So now I wait for one from Mazda. Hurry up and wait, love that game.

 

[Protege03ak46]

Rock auto has several from 35 to 65

 

[Oneofakinder]

Ok, New slave cylinder is installed, and bled. I bled it both ways because I still did not have pressure behind the pedal. I did the traditional bleeding with someone pumping the clutch, then bleeding the air out, then I used a pressure bleeder and bled it from the slave cylinder up the line, and still nothing. So I'm thinking it's gonna be the pressure plate, but I'm still not sure. No leaks anywhere along the line from the master to the slave, not even a drop.

 

[dacquesta1]

can you move the clutch release fork by hand?

 

[Oneofakinder]

no, It moves with the slave cylinder though. I can't budge it by hand at all.

 

[dacquesta1]

If you start the car can you switch through the gears or does it grind/not go in gear

Edit...is the slave cylinder still moving the same amount? How many miles are in that clutch and pressure plate?

 

[Oneofakinder]

It moves quite a bit more with the new slave cylinder, but still not enough to push the pressure plate. If I start it, I am NOT able to run it through the gears. 91k miles on the car, and I'm not the original owner so I dont know if it's ever been changed. The weird thing to me is, I had my dad helping me when I was bleeding the slave cylinder, He had to press the clutch to the floor about 4-6 times before the slave cylinder would fully push the fork. It would move a little with the first few pumps, but took 4-6 pumps before it would fully press the fork??

 

[dacquesta1]

So each time he was pressing the clutch pedal to the floor, the slave cylinder would move a little bit at a time? When you bleed the clutch, does it squirt out a decent amount of fluid from the bleeder valve each time the pedal is pressed down or is it a low pressure almost seeping out of the bleeder?

 

[Oneofakinder]

If I pump it one time, and hold the pedal to the floor, then open the bleeder valve, almost nothing comes out and the slave cylinder moved a tiny bit. If I pump it up 10 times and hold it to the floor, open the bleeder valve I get a decent amount of fluid squirting out of there. I've got it up on ramps in my shop now.

 

[Oneofakinder]

Just bled it again following this procedure. http://www.dsmtuners.com/forums/articles-drivetrain/213503-how-properly-bleed-your-hydraulic-clutch.html and I still have no clutch. I'm thinking throwout bearing, or pressure plate. Almost like the throwout bearing isn't pushing the pressure plate far enough.

 

[StealthWyvern]

check your brake fluid cap.. if it has stress cracks replace it.. also if your fluid is over filled it can cause you to not have a clutch as well (think filled to the brim and then the cap was put back on) . Another thing to look at would be the clutch line but im sure you would of noticed a leak on it while bleeding it out.