Clutch pedal inconsistency

Noticed over the past week or so that my clutch pedal is not consistent on every stroke. Every now and then it seems like the pressure is a little less or a bit more than normal, or the engagement point is a little notchy at times and then will be smooth again out of nowhere.

It should be noted that operationally it's been perfectly fine, shifting normally, not losing any clutch fluid at all.

Has anyone experienced this? I was thinking that maybe either my master or slave cylinders could be on the way out This is a Southbend clutch (TZ/FE combo). Really hoping it's not something internal that requires dropping transmission.

Thanks,
Mike

One thing is the check is behind the boot on both the master and the slave.

I had this issue a few years back, it was my master, it was leaking but nothing ever dripped out, all the fluid stayed inside the boot, which actually wasn't much at all, without marking the level on the res I don't think you could tell but but it was enough to mess with it.

I had similar symptoms and also found a slowly-seeping master cylinder. However, I also know that the clutch pedal was adjusted out too far at that time, which can screw with the self-adjustment of the slave cylinder. When I put in the new master it was properly adjusted, and I haven't had the issue since.

If you find no fluid behind the dust boots of either the master or slave, I would make sure that your pedal is adjusted as per Jack's video.

Thanks guys, I'll have a closer look this evening and see what I can find out.

Wouldn't surprise me that the master needs to be replaced, as I had an ACT 2900 PP in there before which was extremely heavy and destroyed everything within a 10 foot radius of it! The pedal adjustment should be BK, I've always gone by Jack's grainy youtube video

I've put about 5,000 kms on this since installing the clutch so I don't think I have the needle valve blocked off inside the master cylinder, but anything's possible I suppose...

Something similar happened to me when my clutch pedal lever cracked.

Jeff, this was the lever inside the car under the dash? On a 2G or 1G?

I had a look underneath last night (very quickly) but didn't notice anything obvious. I was really just checking to make sure the cylinder rod adjustment nut hadn't come loose...

Normally it causes an issue down the road. The slave will be properly adjusted to your clutch before you adjust the pedal. If you then block the valve, then once the clutch begins to wear, you get issues.

You say you've adjusted it according to Jack's videos though, so I'm sure it's fine. It is quite easy to check though: reach under and try to push back your slave. If you can push the rod into the cylinder by hand, then the valve is operating fine.

Inside the car, 2G, cracked right where the pivot was welded. The lever was bending and thus "stealing" some of the input from my leg. I spent alot of time and money chasing that one.

It's most likely a hydraulic issue, but it never hurts to check.

Thanks Jeff. The pedal itself and all welds looked fine. I did notice a small drip of fluid on outside of the boot, not enough to run down but it was there. There's also a bit of fluid inside the boot, so I guess it's safe to say the master is on its way out.

Going to have to order one, but hoping the car will continue to be fine to drive until I get it...

Thanks fellas

Ziggy also sells a rebuild kit for the oem master, a slightly cheaper option if you want.

how can i tell if my current master is oem or aftermarket

On a 2g it says Nabco on it.

I bought an aftermarket unit before that also said Nabco and looked identical to the OEM unit...not sure if there were any differences but they were not visible.

Either way, the ACT2900 I had at the time managed to destroy it prematurely....never again!

Southbend all the way.

Mike

Update on this: Replaced master cylinder with new OEM, bled using RRE's instructions and adjusted according to Jack's video, and everything is good now.

Thanks for the input.

Mike

Glad to hear she's sorted

Have to resurrect this thread, as my issue is not sorted out like I thought it was :

New master, not leaking any fluid at all. Clutch pedal is not spongy, has been bled multiple times, so I don't think this could be related to air in the lines.

When the car is cold or hasn't been driven in awhile, the clutch feels great, but after a couple minutes of driving I get the 2G Pedal Pump-Up "feel"...pedal gets really stiff at the bottom near the floor, I lose the freeplay at the bottom of the pedal, and shifting becomes painful.

The weird thing is that it's not pedal pump-up, as I know I'm not blocking off the pressure relief valve in the master cylinder, since I can push in on the clutch fork by the slave no problem.

Actually, when I press in on the clutch fork, it actually makes the pedal feel good at first, but it quickly reverts to feeling like crap once I drive it.

Anyone ever experience these symptoms?? I'm at a loss here, master is brand new, slave is only a year old, not leaking, no air in line that I can tell, master cylinder rod adjusted correctly. I also can't see any mechanical issues with the clutch pedal assembly itself...

Can air in the line cause this, or would air only make the pedal feel spongy/soft? Otherwise I'm thinking I got a faulty master cylinder which is doubtful as these are same symptoms as with my master that was just replaced.

Please help if you can...thanks.

Mike

I've been paying very close attention to the symptoms over the past few days of driving, and it's very consistent. Basically, first thing in the morning, car is cold, the clutch is PERFECT.

As I drive it and it warms up, my clutch pedal engagement point lowers to the point where it engages right off the floor (as opposed to approx. 2 inches off the floor when I started).

So I think it's only one of two things:
1) Faulty master cylinder
2) Clutch fluid has absorbed water which is lowering the boiling point of the fluid, causing it to perform poorly as it heats up

Anyone think I might be on the right track here? I am going to get some new DOT4 fluid and flush the entire system. If that does nothing, then I think I'll need a new master.