Clutch not disengaging

[jawn101]

I"m still betting on the master cylinder. I had one fight me like this last week.

Well, that's a much easier thing to try than dropping the whole lump again. I still have the original master laying on the garage floor, leaky or not it's still a valid test...

[vwdmc16]

Josh, approximately how much travel should the slave cylinder produce with a good working system?

[LEVY]

You should test your car on the street before you continue any further.

If something got caught in between your clutch disc and either side, that alone may cause the problem you are describing. A little force may release and fix it.

LEVY

Thanks David - yes, we have the wheels up in the air but the open differential is not the reason they keep going. It's actually impossible to get it to change gears after it's in. If I start the car in neutral, I can't disengage the clutch enough to get to first. If I stop the motor and put it in first, then start it up (wheels up), I can't get from first to any other gear.

I do plan on calling John in the morning but I figured I'd go after some other expert opinions. The flywheel is just an OEM one that has been resurfaced, and I trust Josh's work very highly on that.

[jawn101]

You should test your car on the street before you continue any further.

If something got caught in between your clutch disc and either side, that alone may cause the problem you are describing. A little force may release and fix it.

LEVY

I don't know what if anything could have gotten caught in there. Problem I foresee is that it is impossible to get the car out of neutral with the motor running, so with the wheels down I won't be able to get backed out of the garage.

[LEVY]

Whit the wheels on the floor, you should be able to do it.

Just be very carefull in case the car moves while in neutral.

When you have the car on the floor, hit the brake pedal all the way down and try to start (in neutral). If the car start and does not move, then you are OK. If the car is in neutral and does not move, you should be able to shift at will!

If, your car does not move in neutral, then slowly release the brake to see if your vehicle stay still. If your vehicle start moving slowly when you release the brake, then you might need to adjust the clutch a little bit.


Note:

If you still not able to shift, try starting your car in reverse with the cluch all the way down if you can ,(don't know if Deloreans have a safety feature to avoid starting while in gear but I doubt it.).

LEVY

I don't know what if anything could have gotten caught in there. Problem I foresee is that it is impossible to get the car out of neutral with the motor running, so with the wheels down I won't be able to get backed out of the garage.

[Delorean Industries]

I was pushing towards not condeming the new master cylinder. I think you still have air in the system.

[David T]

If you are getting full movement on the clutch slave then your problem is not air in the hydraulics. Easy to verify. Have someone step all the way down on the clutch pedal while you watch the clutch fork. There is NO neutral start inhibit switch on the 5-speeds, ONLY the automatics. That circuit gets jumpered but is still there. Put the car on the ground in neutral, block the wheels, set the E-Brake, step on the clutch and try to start it. If it won't crank and wants to move you have a problem with the clutch. If you want to try it up "in the air" set the E-Brake and try starting it. Make sure the E-Brake will lock both wheels. You can also step on the service brakes. Do not confuse a lot of drag from the clutch with it not disengaging.
David Teitelbaum

I was pushing towards not condeming the new master cylinder. I think you still have air in the system.

[jawn101]

Thanks for all the feedback, guys. I will go home this evening and try some of these tests and keep a detailed log of what I find under what circumstances. But I can say this much - the car starts in neutral, no issue. The wheels don't move (off the ground, on stands) when the motor is running in neutral. But if the engine is running, in neutral, and I depress the clutch to the floor, I can't select a gear. If I select a gear with the motor off and start the engine, it starts but I cannot then depress the clutch and select a new gear. The slave cyl does move, about 1" when the pedal is depressed all the way. What effect that has on the fork is unknown - how can I view that?

[Bitsyncmaster]

Did you measure the old and new clutch plate? I hope this is not your problem but there has been talk of some not machined to proper thickness.

[DMCMW Dave]

Did you have any trouble aligning the disc and getting the transmission installed? A bent disc will do this too, but it will show up as a hard-to-install trans.