Problem With Clutch

Hello all my name is: Lex
I have a: 1994 Mitsubishi 3000GT VR4
It has the following issue:
When I press the clutch pedal and try to shift from neutral into 1st or 2nd or any gear except 4th, it does not go in.
If I keep pressing the clutch (not pumping) just holing all the way in to the floor (firewall) in 2-5 seconds it goes in.
I have replaced clutch Master and Slave cylinders and did bleed the system.
My vacuum booster for the pedal doesn’t work but I don’t think that should be a problem as all it does is make it easier to push the pedal.
Hopefully someone knows what it could be as no one that I have talked to has ever heard of anything like that.
Thank You.

Are you able to shift gears smoothly with the car off?

Yes, when the car is off. It shifts very smooth.

I’m pretty sure you need a new clutch

I don’t think so, because there are no problems with engagement and it shouldn’t matter if the clutch is worn or not for gear shifts.
I have thought of that possibility though, that’s why I adjusted my clutch pedal for the potential wear and then some.
Like I have said it is a weird problem.

I’ve had a burned out clutch but allow me to shift while running before. The other issue you could have is low break fluid in the system, or air in the line. How soft or firm is the pedal?

The pedal feels fine and as I stated before I have blead the system… Didn’t see any air bobbles.
That was my initial hypothesis.
I still have no idea of what it could be.

Update after a quick google … pressure plate or clutch disc section 3

Thank you for the article.

In my case everything works but only with a delay. (which is weird)
To me it feels like the system is not building enough pressure or something like that.
Or doesn’t push clutch fork far enough quickly.
Still trying to figure out.

It is worth checking that the slave cylinder is moving freely and pushing the clutch fork to its full extent. I can’t tell whether you changed the slave before or after you started getting the problem. To me it sounds like the slave cylinder is resisting OR you’re not getting enough pressure behind it due to a leak or air in the fluid. It’s the only thing can think of from the info you have provided. good luck

On second thoughts if everything works but is delayed then surely this points to your vacuum booster ?

That’s what I’m afraid of.
I have not idea of how that works.

On further research I think its not the booster. A fault with the booster will only make it harder to push the pedal for the slave piston to move the same distance. My money is on air in the system. The air is absorbing some of the pressure in the system and delaying the time the clutch fork reaches the correct position… Either that or a leak. When did you replace the master and slave cylinders ? Before you had issues or after ?

Something that’s happened to a friend’s Lancia was the throughout bearing was misaligned. One test you can do is put it in 1st gear, start the car, and if the car starts to move while your foot is on the pedal, then you have a stick clutch.

The problem happened after replacement of master clutch cylinder, however it might have been there before except not to that degree.
I don’t think its the air either because it just wouldn’t push further after a while it would just compress air and not have enough pressure. Kind of like what happens to brakes when there is air in the lines.
There are no leaks, not loosing any fluid.

Thanks 91GTOtt,
My car disengages the clutch when I press on the pedal, but doesn’t go in gear until some time passes.
So it can not (as far as I can tell) a clutch disk or plate or bearing issue, but at this moment I’m not sure.

When you swapped out the clutch master cylinder did you do anything with the booster ? If somehow the vacuum is working in the wrong direction ( or a valve is stuck etc) it might explain why the system is resisting a gear change instead of easing it. If you are convinced there is no air or leaks then it must be a problem with a valve or piston in either the master ,slave or booster.You’ve got to ask the question what changes when the engine starts ? answer … clutch booster

Actually my clutch booster wasn’t working when I have bought the car. I never cared about it because I like that I can feel the clutch better this way. Then my MC cylinder failed and I replaced it with an aftermarket unit and that’s when this problem began. So I replaced MC cylinder with OE unit and SC cylinder with an OE unit as well. I’m starting to wonder if it could be synchronizers.

1 Like

So either way you’re going to have to remove your gearbox … which will give access to check out your clutch plate first. : Hopefully the link I posted may have given the answer after all.

I’m trying to avoid taking transmission out at all cost.

1 Like