PoLaK

iTrader: (1)

Hey guys I've having a rather odd problem, this happened both before and after I installed a aftermarket clutch/pp/and flywheel combo, so I doubt is a problem with those parts specifically, I also replaced the throwout bearing so it can't be that.

When slipping the car into first gear toward the end of letting my foot off the clutch pedal i'll get a kind of sticky feeling "pop" felt though the bottom of my foot. It’s usually only while the car is warming up and when it’s very hot outside. Almost like there’s a piece of chewing gum stuck on the clutch pedal.

Since you have to remove the clutch slave when you install a new Clutch/pp/flywheel I don't think its that either, any ideas?

Charles R. Hill

iTrader: (7)

Didja bleed the slave cylinder after you were done with the swap?

CRH

TeamRX8

iTrader: (25)

a bleed wouldn't hurt anything just to be sure other than the slave cylinder is a PITA to get to.

I noticed after unbolting my slave from the bellhousing recently that pedal was a bit low upon reinstallation, pulled the pedal all the way up and depressed it, repeated, and this corrected the issue

Charles R. Hill

iTrader: (7)

Approaching from the driver's side of the car and reaching down with a 1/4" drive ratchet or box-end wrench I was quite able to bleed the cylinder. Almost as easy as when I swapped the cat-back out.

CRH

TeamRX8

iTrader: (25)

I didn't try it from up top, I was underneath the car dropping the trans and unbolted it from there, thanks for the heads up

Charles R. Hill

iTrader: (7)

In that case, I agree with you. I also found it difficult that way.

CRH

PoLaK

iTrader: (1)

No bleeding, I also experienced a change in where the clutch grabbed after reinstallation, but it’s not because of how I position the clutch slave, it’s because the redesigned 05 throwout bearing is thicker and therefore larger in length dimensionally.

Once again this occurred both before and after i installed the New PP/Clutch/and Flywheel so i don't thinks it’s something to do with my meddling.

TeamRX8

iTrader: (25)

that wouldn't necessarily mean it doesn't need bleeding, particularly given some of your past useage at the strip, there's a lot of heat under there

I didn't think it would be that either, but then got to thinking that if you had a small bubble such that you could compress it and still have enough clutch travel, yet it would show itself at the end of the pedal release so I wasn't quick to discount Charles' theory

it's a long shot ... not sure how else you could explain it though

Charles R. Hill

iTrader: (7)

If the TO bearing is "deeper" in its dimension then I would guess that a pedal adjustment would be next(?). It might only change the pivot angle of the clutch fork slightly, at most, and shouldn't be a problem.

CRH

TeamRX8

iTrader: (25)

actually the slave cylinder will automatically adjust to the dimension change, I'm pretty sure that the pedal adjustments are independent of the slave cylinder rod engagement position

Charles R. Hill

iTrader: (7)

Now that you mention it, I am not sure that even a pedal adjustment would make a difference if the bearing dimension turned out to be an issue. Assuming there is no air in the line and both clutch master and slave cylinder's pistons were in the proper position I can't think of how the hydraulic system is prepared to accomodate any change in T/O bearing "depth". There is no adjustment to the clutch fork depth, either, so I am thinking that the bigger T/O bearing may have too much preload on it. What do you guys think?

CRH

PoLaK

iTrader: (1)

Hummm now that you mention it perhaps some air got into the line and the pop I'm feeling is a gap in the fluid, and perhaps it happens more frequently on hot days because the master cylinder and it fluid is hot as hell?

TeamRX8

iTrader: (25)

The system will simply accommodate the change of the slave cylinder plunger position. In the case of a thicker throwout bearing the PP diaphram spring pressure simply pushes the slave plunger rearward and the fluid backs up into the reservior. In the opposite situation the system simply uses hydraulic fluid to fill the area between the slave and master to move the slave plunger forward until it encounters resistance at the fork. Neither the clutch master cylinder nor the slave is dependent on the fork position. They simply transfer a specific volume of fluid into linear motion. The pedal adjustment comes in as the determining factor on what that specific amount of fluid is based on the pedal starting and stopping positions, as well as the amount of freeplay between the pedal and master cylinder plunger.

As I explained earlier, when I removed and reinstalled the slave my clutch pedal was low. I had to reach down and pull the pedal back, which resulted in fluid filling the master cylinder plunger cavity with hydraulic fluid out of the reservior. I had to do this twice, at which point enough fluid had filled the system until the slave plunger moved forward and contacted the fork. The system had reached a full static volume and the pedal was back to it's original position with the slave ready to engage the fork normally. The only connection between the pedal and the rest of the system is the master cylinder plunger rod. There is suppose to be freeplay between the clutch master cylinder plunger rod and the pedal.

How can the hydraulic system determine pedal position if it always has freeplay between it and the pedal?

That said, you have to start troubleshooting the system somewhere and a small bleed just to make sure the hydraulics are purged of any air is the easiest item to start with. It can't hurt and will at a minimum eliminate that possibility. It will either correct the situation or if not then indicate that you'll need to look deeper.

Next I would check clutch pedal freeplay to make sure you didn't experience some kind of strange wear that through this off. Then I would check the pedal start and stop positions. Beyond that you'll probably have to drop the transmission. A long shot would be that either the master or slave cylinder has some kind of internal issue for whatever reason.