Time for a new clutch or something else?

[Stainless]

Two days ago, my clutch was fine. Yesterday, from the moment I got in the car, the clutch pedal felt very soft, like it didn't take much effort to push it in. When I went for a drive, it was very hard to get into gear, especially first. It wasn't difficult to get it into the other gears. It felt like I had to push the pedal as far as it could go before it felt like it was doing anything. I was able to make it home though.

Today, I went to try and diagnose the problem, and now the problem is much worse. The clutch pedal has no resistance and I can't shift it into 1st gear or reverse when the car is running. All it does is grind the gears. In all the manual transmissions that I've owned, I've never had a clutch go out on me, so I'm not sure if it's the clutch, the master cylinder, the slave cylinder, or something else. I am able to shift into gear when the car is not running, if that tells you anything.

Looking at all the paper work from previous owners, nothing has ever been touched with regards to the clutch components, so everything is completely original. Mine is an '81 with 52K miles. Let me know where I should start. Thanks.

[Patrick C]

Check your clutch fluid. The problem sounds hydraulic.

[1batt4u]

Check for leaking oil, from the clutch line, to the clutch cylinder, slave cylinder. See if any oil is dripping out the clutch cylinder, where the pedals are, into the floor.

[Stainless]

The good news is that I don't believe that the clutch is bad.

The clutch fluid container was bone dry. After filling it up and pumping it a lot, the clutch feels pretty good again, meaning I can get it into gear with the car running. I found that the car's clutch pipe has been replaced with a SS braided line. I couldn't find any leaks on the outside of the vehicle, even when my wife pumped the clutch pedal.

I believe the culprit is a leaking master cylinder. Down by the pedals, this is what I found:
http://i173.photobucket.com/albums/w57/jlattin21/DSCN0355.jpg

After pumping a few times, I was able to sit and watch fluid slowly drip out of it. It looks like I'll be replacing the master cylinder. Luckily it doesn't seem like it should be too hard of a job. My question is, how do you access the slave cylinder to bleed the system once the new master cylinder is installed?

[jawn101]

From above the engine, behind the intake as I recall. Kind of a pain.

[opethmike]

It is a lot easier if you stand on a step stool and lean right over.

[Chris Burns]

You have to be a proctologist to replace the slave cylinder.

[Ron]

It looks like I'll be replacing the master cylinder. Do yourself a favor and replace them both...

[DMC5180]

+1

[Kenny_Z]

Definitely replace them both. The slave isn't bad but getting that metal hose back on is horrible. I had to walk away a couple of times before I broke something. It'll fight and fight and then suddenly fit like it had always been there. Get yourself a step stool and lay across the engine.

[outatym2001]

The answer you seek is in one of the threads below.

http://dmctalk.org/showthread.php?2061-Clutch-Master-Slave-Recommendations
http://dmctalk.org/showthread.php?124-SpecialTAuto-Clutch-Bleeder-Line
http://dmctalk.org/showthread.php?1864-Still-have-clutch-problems

People are going to tell you since you have no records of when the clutch master or clutch slave cylinder has been replaced then it’s time to replace both together. When one fails the other soon will.
It’s a pain to bleed but I removed the Engine Cover then laid one layer of cardboard on the engine then a blanket on top of that.
I laid on the blanket and looked down in between the fiberglass firewall and the engine intake plenum and there resting on top of the transmission is the clutch slave cylinder. Not a easy thing to see with the black hoses and wires that are in your way.
Removing and then installing a new slave cylinder and then bleeding is no fun but it’s doable.

Here is a good web site with pictures.
http://specialtauto.com/delorean-parts/clutch-transmission.html

Man O’ Man John Hervey’s web site keeps getting bigger!

P.S. Do not overtighten the four nuts when replacing the Engine Cover after your project is finished. You may break off one of the threaded studs on the Engine Cover Hinge.

[David T]

The slave cylinder comes out from underneath. You may have to remove the metal line with it if you can't get it loose. I only do it from the top if I have the intake off at the same time. Removing the engine cover does give you a little better access if you have to try doing it from the top. Look at the brake fluid now. If it is dark and nasty expect to rebuild that system next. Blow out the braided hose with alcohol to get rid of all of the old brake fluid. Change the brake and clutch fluid every other year to avoid having to do this again anytime soon. Definitely do master AND slave now. Wash out the reservoir with alcohol and long swabs to get all of the old junk out. NEVER DRIVE ON A BAD CLUTCH HYDRAULIC SYSTEM! If you do, expect to take the transmission out and all apart to replace a $.29 roll pin! Pull up the carpet on the driver's side and clean up all of the brake fluid underneath the carpet.
David Teitelbaum

[Stainless]

The slave cylinder comes out from underneath. You may have to remove the metal line with it if you can't get it loose. I only do it from the top if I have the intake off at the same time. Removing the engine cover does give you a little better access if you have to try doing it from the top. Look at the brake fluid now. If it is dark and nasty expect to rebuild that system next. Blow out the braided hose with alcohol to get rid of all of the old brake fluid. Change the brake and clutch fluid every other year to avoid having to do this again anytime soon. Definitely do master AND slave now. Wash out the reservoir with alcohol and long swabs to get all of the old junk out. NEVER DRIVE ON A BAD CLUTCH HYDRAULIC SYSTEM! If you do, expect to take the transmission out and all apart to replace a $.29 roll pin! Pull up the carpet on the driver's side and clean up all of the brake fluid underneath the carpet.
David Teitelbaum

Thank you Mark and David for the additional and useful info. I'll definitely try doing this job from below the car first. I'm glad to hear that it can be done.

The first job I did when I bought my car this year was replace the brake master cylinder. All four calipers have been replaced recently as well, so luckily my brake system is in tip top shape. I didn't even think to check the clutch hydraulics at the time.

For now, I am planning on doing both the master and slave cylinders. As i mentioned before, the line has been changed to the SS line, so no worries there. No driving until this has been fixed! Thanks for all the info guys.

[Mike C.]

but getting that metal hose back on is horrible. I had to walk away a couple of times before I broke something. It'll fight and fight and then suddenly fit like it had always been there. Get yourself a step stool and lay across the engine.

I laid under the car for about 40 minutes trying to get that thing in. Had to get out, and Ozzie climed under my car and had it back on in about 9 minutes! lol!

What I found out was the angle was different than I imagined. When I crawled back under there, I pretty much just smacked my head and said 'oh shit...that's it?!?'

[jmrydholm]

Had mine replaced last summer as well- it was the slave cylinder, in my case. I went ahead and ordered both the master and slave just to be on the safe side. I have one of John Hervey's clutch pedals from 2004 in the car with about ~5K miles on that. Shifts like a dream! Taught myself how to drive a manual trans on it.

-John R.
#10715

[jawn101]

Taught myself how to drive a manual trans on it.

Great car for it if you ask me. The gears are so perfectly spaced that it would really show you how a stick should feel. And I don't know if they're all this way, but my clutch is so perfectly forgiving it's tough to screw it up.

[jmrydholm]

Great car for it if you ask me. The gears are so perfectly spaced that it would really show you how a stick should feel. And I don't know if they're all this way, but my clutch is so perfectly forgiving it's tough to screw it up.

One fun memory from college: stalling on the way to class, still rolling, popping the clutch and re-starting the car, all while watching the surprised look on the faces of the other drivers around me! I kind of was in an emergency situation there, as it was the middle of traffic. I'm just glad there was a left turn lane there with no one in it.

Another time, my starter gave out. So I threw it into reverse and rolled it down a hill in a parking lot. Nearly hopped up onto the sidewalk, but she started!

[David T]

The Delorean may be a good car to learn "stick" on but it is not a good car to teach in. The passenger/instructor can't see the pedals and can't reach the E brake. I disagree that the gear ratios are good. 1st is too long and 2nd is too short. You can skip 3rd altogether. The ratios were not optimized for the Delorean. The best gear is 5th over 40 MPH.
David Teitelbaum

[Stainless]

Thanks for all the good info guys. Right now I am assuming that I do NOT need to perform a bench bleed of the clutch master cylinder like I had to do for the brake master cylinder. I have found no mention of this on any of the threads I have read and I just want to confirm that is correct. Thank you.

[outatym2001]

Yes, that’s correct no bench bleeding necessary. I installed the new clutch master cylinder and secured everything tight then added Castrol GTLMA to the white plastic reservoir and started slowly depressing the clutch pedal to get fluid moving through the new stainless steel clutch fluid line. The bleed screw was open slightly at the slave cylinder with a hose attached to the bleed screw and the other end resting in a plastic bottle resting on the ground.
Do not let the reservoir container run out of fluid. You don't want to introduce more air bubbles into your new system.
Pretty sure I had a 32 fluid ounce bottle of Castrol GTLMA just in case I wasted some while trying to get air bubbles out.

[Stainless]

I can use the same DOT 4 brake fluid that I used for the brakes, right?