Clutch pedal

[Helirich]

On my car, I have to push the clutch right to the floor to get it to completely disengage. When I say “to the floor”, I mean until the metal of the clutch pedal hits the metal of a brace down there. I have carpet against the brace and it is being cut by the pedal bar. This doesn’t seem right.

I looked closely and I notice the pedal will move about 1/2” before anything happens. (It’s just compressing the spring) The pedal moves and the linkage moves, but the pin moves that far before contacting the piston. It seems to me if the pin from the linkage was a 1/2” longer, everything would work better. Has anybody else run into this?

The only adjustment I see is a pedal stop on the “up” side. I could adjust it so I get rid of the 1/2” play, but that doesn’t stop me from hitting the floor. Is it possible the piston is not coming back completely? (It’s a new cylinder)

IÂ’m thinking of welding a longer pin to push the piston right away.

Edit, does everybody see these Swedish “A”s next to my quotation marks? What causes that? It only does it on this forum.

[WHO1DMC]

The clutch master is not that difficult to remove just a little time. I would rather fix or replace than put a bandaid on it.
I replaced my master and slave this year. I lost clutch hydraulics altogether on a drive. Luckily I was on my way home. Had to start the car in gear at stops.


Dave B.

[Ron]

Edit, does everybody see these Swedish “A”s next to my quotation marks? What causes that? It only does it on this forum.No idea why it didn't do it in the portion quoted above... For the others, I'm seeing Unicode characters (8220 and 8221). Try setting your browser's encoding to Western ISO-9959-1 if you can.
Post in the forum support section if no luck.

[Helirich]

The clutch master is not that difficult to remove just a little time. I would rather fix or replace than put a bandaid on it.
I replaced my master and slave this year. I lost clutch hydraulics altogether on a drive. Luckily I was on my way home. Had to start the car in gear at stops.


Dave B.

As I said in the OP, the master is new. (Less than a year) Are you saying there is no lost motion on yours?

[Helirich]

No idea why it didn't do it in the portion quoted above... For the others, I'm seeing Unicode characters (8220 and 8221). Try setting your browser's encoding to Western ISO-9959-1 if you can.
Post in the forum support section if no luck.

Where do I find “browser encoding”?

[WHO1DMC]

As I said in the OP, the master is new. (Less than a year) Are you saying there is no lost motion on yours?
Sorry it was late I missed that it was new.

No. Constant pressure all the way through. Just for clarification I put in all DMCH components. Plus I reverse bleed mine.



Dave B.

[David T]

Try rebleeding the clutch hydraulics. If that doesn't work you probably have to replace the clutch. You should get release way before you get to the floor.

[Henrik]

...does everybody see these Swedish “A”s next to my quotation marks?

The term "Swedish “A”s" was a new term for me. Funny, because because I am Swedish myself... but I see what you're saying. You are referring to the three letters: Å, Ä and Ö.

[Dickey]

On my car, I have to push the clutch right to the floor to get it to completely disengage. When I say “to the floor”, I mean until the metal of the clutch pedal hits the metal of a brace down there. I have carpet against the brace and it is being cut by the pedal bar. This doesn’t seem right.

I looked closely and I notice the pedal will move about 1/2” before anything happens. (It’s just compressing the spring) The pedal moves and the linkage moves, but the pin moves that far before contacting the piston. It seems to me if the pin from the linkage was a 1/2” longer, everything would work better. Has anybody else run into this?

The only adjustment I see is a pedal stop on the “up” side. I could adjust it so I get rid of the 1/2” play, but that doesn’t stop me from hitting the floor. Is it possible the piston is not coming back completely? (It’s a new cylinder)

IÂ’m thinking of welding a longer pin to push the piston right away.

Edit, does everybody see these Swedish “A”s next to my quotation marks? What causes that? It only does it on this forum.


Any chance you took a picture of the two MCs where you can reference if the piston is legitimately 1/2" further inboard on the new one or perhaps kept the old MC on hand to compare against? I've made plenty of custom pedal pins over the years for my cars but I've only ever had to do it when I wanted to use a clutch or brake master cylinder that wasn't meant for the pedal assembly that was in the car.

[Helirich]

Try rebleeding the clutch hydraulics. If that doesn't work you probably have to replace the clutch. You should get release way before you get to the floor.

That’s what I was thinking. It’s been a few months since I changed the master. I’m not really sure if the clutch pedal has always required full travel to release. The fluid is still full. I wonder if the piston got hung up somehow. I’m literally just pushing the spring for the first inch on the pedal. That translates to about 1/2” on the actual pin that pushes the piston. If it would be pushing the piston immediately, it would be so much nicer.

I need to investigate more.

[Helirich]

The term "Swedish “A”s" was a new term for me. Funny, because because I am Swedish myself... but I see what you're saying. You are referring to the three letters: Å, Ä and Ö.

I don’t really know what they are called. Seems like I’ve seen them in some foreign writing. (Swedish, Austrian, Danish)


Any chance you took a picture of the two MCs where you can reference if the piston is legitimately 1/2" further inboard on the new one or perhaps kept the old MC on hand to compare against? I've made plenty of custom pedal pins over the years for my cars but I've only ever had to do it when I wanted to use a clutch or brake master cylinder that wasn't meant for the pedal assembly that was in the car.

Didn’t keep the old master. The old one didn’t work at all. It would leak the whole resivour overnight.

When I started noticing this, I thought it was just the thick carpet mats getting in the way. But when I got down and looked close, the pedal is cutting the mat.

[Andrew]

Rob Grady sold an adjustable clutch linkage that I’m running on both 4194 and 5052. It’s easy to install and the results are great. I’d recommend contacting Rob to see if he still has one available.

Also, are you running stainless braided clutch hydraulic line. If not, I would perform that upgrade without delay.

Best of luck!

Andrew
4194
5052

[Helirich]

Rob Grady sold an adjustable clutch linkage that I’m running on both 4194 and 5052. It’s easy to install and the results are great. I’d recommend contacting Rob to see if he still has one available.

Also, are you running stainless braided clutch hydraulic line. If not, I would perform that upgrade without delay.

Best of luck!

Andrew
4194
5052

I do have the braided line. Do you have a picture of the “adjustable linkage”? I have a pretty complete machine shop at my house, so I can probably make one. I’ve thought of several ways to do it already. I would have made one already, except I don’t want to do it if there is something wrong. (I don’t want Band-Aid if the piston is hanging up.)

[Rich]

I do have the braided line. Do you have a picture of the “adjustable linkage”? I have a pretty complete machine shop at my house, so I can probably make one. I’ve thought of several ways to do it already. I would have made one already, except I don’t want to do it if there is something wrong. (I don’t want Band-Aid if the piston is hanging up.)

An OE style MC and slave will not need any adjustable hardware.

Early on some of the original DMC dealers sold an adjustable link for the clutch. I assume it was a band aid for the problem with the original clutch line. I took the "dealer" adj. link out a few years later and went back to the OE link (after moving to the braided line). No problems.

Is your system is fully bled per David T's advice earlier? If you don't know for sure that the system is bled then any linkage work might be a band-aid.

The symptom you describe is consistent with air in one or more of the 3 components (MC, clutch line or slave). Bleeding the clutch isn't easy but you might as well get good at it sooner than later given the recommended flush/fill frequency (2-3 yrs).

[82DMC12]

I want to get DPI's remote clutch bleeding setup. I think I'm through trying to bleed my slave from above the engine. It's no fun.

https://deloreanindustries.com/3-2-remote-clutch-slave-bleeder-stainless-factory-slave/

Does anyone have this and can post a picture of where the remove bleeder goes "near the bellhousing by the starter"?

[FABombjoy]

Do you have a picture of the “adjustable linkage”?

ST-07-9/82 describes the adjustable link that replaces the original fixed link. Rob's version was a hardened version that addressed some issues with wear on the factory part & clevis pins.

My car had the OEM adjustable part. Rather than remove the pedal stop I think either a QAC or dealer just stuck a bottle jack under the clutch pedal and bent it 45 degrees up.

I don't fully understand why there is an upper stop bolt for the clutch pedal. This seems a dangerous design that could zero out pedal free play once things are warm and trash your throw-out bearing.

[Bitsyncmaster]

ST-07-9/82 describes the adjustable link that replaces the original fixed link. Rob's version was a hardened version that addressed some issues with wear on the factory part & clevis pins.

My car had the OEM adjustable part. Rather than remove the pedal stop I think either a QAC or dealer just stuck a bottle jack under the clutch pedal and bent it 45 degrees up.

I don't fully understand why there is an upper stop bolt for the clutch pedal. This seems a dangerous design that could zero out pedal free play once things are warm and trash your throw-out bearing.

My car does not have the stop bolt for the clutch. It also has Robs adjustable link. Hence my clutch pedal does sit higher than the brake pedal. That does not bother me but I would guess I could adjust the link to lower it. It's been that way since I bought the car. Without the stop, you really can't miss adjust the pedal because you always have free play at the top.

[Helirich]

An OE style MC and slave will not need any adjustable hardware.

Early on some of the original DMC dealers sold an adjustable link for the clutch. I assume it was a band aid for the problem with the original clutch line. I took the "dealer" adj. link out a few years later and went back to the OE link (after moving to the braided line). No problems.

Is your system is fully bled per David T's advice earlier? If you don't know for sure that the system is bled then any linkage work might be a band-aid.

The symptom you describe is consistent with air in one or more of the 3 components (MC, clutch line or slave). Bleeding the clutch isn't easy but you might as well get good at it sooner than later given the recommended flush/fill frequency (2-3 yrs).

I’m sure I bled it when I installed the new master. (DMC) I remember cussing at the location. I’m hoping it’s easier with the crossover pipe gone. Does that make any difference?

I was thinking of pealing the rubber boot back under the dash. I would like to confirm that the pin is moving free for that 1/2” before it hits the piston. Also maybe I can see from that side if the piston looks to be the whole way back. If the piston is moving the 1/2” with the pin, I would say I have a serious air in the system problem. I can’t hardly believe that. I should have checked it today.

[FABombjoy]

I should have said "trash your throw-out bearing and pressure plate".

The stop bolt is a curious part. I can't find it in pedal box or clutch portions of the service manual. Its visible in the parts manual at 6:4:0 but not at 4:4:0. Since it could interfere with clutch release if misadjusted I'd think it would have appeared somewhere besides the TSB? My last manual car w/ hydraulic clutch definitely saw some clutch pedal movement when hot as things expanded. An upper stop bolt adjusted cold would have caused it to preload or slip when hot.

Other Lotus cars have it... and the 2019 Civic Type R? :confused:

[Helirich]

I should have said "trash your throw-out bearing and pressure plate".

The stop bolt is a curious part. I can't find it in pedal box or clutch portions of the service manual. Its visible in the parts manual at 6:4:0 but not at 4:4:0. Since it could interfere with clutch release if misadjusted I'd think it would have appeared somewhere besides the TSB? My last manual car w/ hydraulic clutch definitely saw some clutch pedal movement when hot as things expanded. An upper stop bolt adjusted cold would have caused it to preload or slip when hot.

Other Lotus cars have it... and the 2019 Civic Type R? :confused:

Mine has the stop bolt. No danger of heat taking up all that travel. But that’s on my list of things to check. (See if the free travel gets less after warm up.)

[Helirich]

So I pulled back the rubber boot and found you can pull the pin out. It’s held there some how. I’m definitely not moving the piston in the beginning. One thing I noticed was the bell crank mechanism changes the throw so the 1/2” of play at the pedal is about a 1/4” at the cylinder. I went ahead and bled the system real good. Don’t think it made any difference. I did pull my carpet/mat back as far as it would go. Now it doesn’t get in between the metal frame and the pedal bar.

If anybody would like to compare theirs, my pedal sits 1/2” higher than the brake pedal. When I push it, it gets perfectly even with the brake before I have any real resistance. I have to push it right to the metal if I’m shifting to reverse or first gear. The other gears is not much of a problem because I can match rpms pretty good now.

I guess IÂ’m going to make a custom linkage at the bell crank to get rid of some of that play.