Stuck clutch pedal

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darrylg
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Stuck clutch pedal

Post by darrylg »

I was driving to work yesterday morning when I depressed the clutch pedal and it never fully returned to the retracted position. I tried to pump it, but it was basically down to the floor.

I got the car to the side of the road safely and I was able to pop the pedal back out with my hand. I drove the car back home and everything felt fine, leading me to believe this was just a simple mechanical issue with the pedal shaft.
What can I do to make sure this doesn't happen again?
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Brucey
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Re: Stuck clutch pedal

Post by Brucey »

if the clutch behaved normally afterwards, this is absolutely symptomatic of a worn MC seal that doesn't 'catch' first time (a bit like a worn bicycle pump...).

The pedal needs hydraulic pressure to return properly; without it, it will stay down by design, because there is a clutch compensation spring that (after the pedal is pushed down 1" or so) goes overcentre and helps you to depress the clutch pedal.

cheers
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
bpoliakoff
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Re: Stuck clutch pedal

Post by bpoliakoff »

My guess is oit could also be a cracked pedal bracket. A common problem and shows the same symptoms Brucey described
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darrylg
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Re: Stuck clutch pedal

Post by darrylg »

Brucey wrote:if the clutch behaved normally afterwards, this is absolutely symptomatic of a worn MC seal that doesn't 'catch' first time (a bit like a worn bicycle pump...).

The pedal needs hydraulic pressure to return properly; without it, it will stay down by design, because there is a clutch compensation spring that (after the pedal is pushed down 1" or so) goes overcentre and helps you to depress the clutch pedal.

cheers
Interesting. I thought the spring was used to return the pedal, not the other way around. Thanks for the info.

I just looked at it, and the MC shows no signs of leaks. I'll try to jack the car up and check on the other side of the firewall. I don't know how you guys work on these cars :o My low profile ramps dont even get under there.

off topic a bit, but what are the two pieces of electronics under the steering column panel?
pic taken from the bigcoupe tech articles:
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wattsmonkey
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Re: Stuck clutch pedal

Post by wattsmonkey »

[quote="darrylg"}
Interesting. I thought the spring was used to return the pedal, not the other way around. Thanks for the info.

off topic a bit, but what are the two pieces of electronics under the steering column panel?
pic taken from the bigcoupe tech articles:

Like many aspects of the E24 I had the wrong idea about how the clutch helper spring worked, even referring to it as the "return spring" until Brucey guided me, in his patient and expert manner, towards the path of what-stuff-actually-does!

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darrylg
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Re: Stuck clutch pedal

Post by darrylg »

Thanks!
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Re: Stuck clutch pedal

Post by Pod »

I had this problem with one of my M635CSis. At first I thought it was the pressure plate, but tried replacing the clutch slave first, which resolved the problem.
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bimmerjoe
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Re: Stuck clutch pedal

Post by bimmerjoe »

I changed the slave yesterday, not the easiest job on my back with the car on jack stands. Tried the revers bleeding method of pumping brake fluid through the slave. Seemed to work. I have my clutch pedal back but have not driven it yet. We will see when I get it out and on the road again.
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miklilmag
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Re: Stuck clutch pedal

Post by miklilmag »

Hello
comment about the low profile ramp

i mainly back up on my ramps, and lift the whole front end with my hydraulic jack and put jack stands under it.

If i need to drive on ramps forward i use woodenboards before the ramps to clear the valance;

Franke
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dwcains
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Re: Stuck clutch pedal

Post by dwcains »

bimmerjoe wrote:I changed the slave yesterday, not the easiest job on my back with the car on jack stands. Tried the revers bleeding method of pumping brake fluid through the slave. Seemed to work. I have my clutch pedal back but have not driven it yet. We will see when I get it out and on the road again.
I fear mine needs a new slave, too. I can barely get the clutch to disengage, and I don't think it's an adjustment issue. It works better when the car is cold, and gets worse pretty quickly as things get warm. I need to get under it this weekend.
Dean
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sansouci
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Re: Stuck clutch pedal

Post by sansouci »

miklilmag wrote:Hello
comment about the low profile ramp

If i need to drive on ramps forward i use woodenboards before the ramps to clear the valance;

Franke
My ramps are perforated so I have 2 - 4' long 2x8"s. I put two carriage bolts through the end that just drop into the second highest set of holes in the ramps, keeping them in place. That reduces the pitch of the ramp so that there is no interference with the valence. I may have some pictures that I will attach.

Hey darrylg: where on LI are you?
Ken
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bimmerjoe
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Re: Stuck clutch pedal

Post by bimmerjoe »

My slave was leaking right out space between it and the bell housing. When I changed it, I decided to loosen the bracket where the steel line connects to the rubber hose from the clutch master cylinder as I could not get my flare wrench on the fitting that went into the slave. So I had to undo that bracket & take the slave out, then drop it down and loosen the fitting. The biggest PIA was working on my back & getting everything backwards as I was looking at it upside down. Once I got the slave in it took me FOREVER to get that bracket re-attached. Once done, I filled a small oil pump with brake fluid, attached a hose to one end of that and the other end to the open bleeder on the slave. Pumped away until I think I got enough fluid up to the reservoir, filled the reservoir the rest of the way, reopened the bleeder, a steady stream ran out, closed the bleeder & got in the car, clutch pedal was up & working fine. Started the car & let the clutch out several times (while on jack stands) and seemed to work fine. Still have to find time to let the car down & give it a try. We shall see.
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dwcains
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Re: Stuck clutch pedal

Post by dwcains »

Umm, sounds like fun for me. Thanks for the description of what's ahead. At least it's not like my 350Z, where the slave fits around the input shaft of the transmission, so the transmission needs to be dropped out of the car. The cylinder is plastic, too, if you can believe that.
Dean
Lutz, FL

'85 635 CSi Euro #9402254
'87 Spider Veloce
'92 Spider Veloce
'08 350Z

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bimmerjoe
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Re: Stuck clutch pedal

Post by bimmerjoe »

Yes I can believe that. The slave I took out of the 633 was metal, the one I put in (Got it from Steve at Blunt Tech) did not feel like metal, it was much lighter and does not seem to be made as sturdy as the original. Good Luck!
darrylg
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Re: Stuck clutch pedal

Post by darrylg »

sansouci wrote:
miklilmag wrote:Hello
comment about the low profile ramp

If i need to drive on ramps forward i use woodenboards before the ramps to clear the valance;

Franke
My ramps are perforated so I have 2 - 4' long 2x8"s. I put two carriage bolts through the end that just drop into the second highest set of holes in the ramps, keeping them in place. That reduces the pitch of the ramp so that there is no interference with the valence. I may have some pictures that I will attach.

Hey darrylg: where on LI are you?
Ken
I need to modify my ramps. Also, the rubber feet are missing so now they slide when I try to drive up.


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L.Tigre
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Re: Stuck clutch pedal

Post by L.Tigre »

Hello all- reviving this helpful old post with a new situation and inquiry:

I had the same experience of pressing the clutch in, and not coming back up. It was in my driveway upon backing out. Seemed to resolve itself with just some manual nudging.

From prior posts in this thread I take that as maybe a worn slave cylinder or possibly cracked pedal bracket (btw where would I look for that crack?)

Later in the drive, the clutch just got slippy. I can break its grip at will now while driving, with just hard press on the accelerator. Slips upon launch also, making it hard to drive. It’s not totally gone but not getting consistent grip at the point of friction.

The guy I bought it from about 4 weeks ago said the clutch was new.

Is the slip, like the stuck-down pedal, a possible symptom of old hydraulics needing refurbishment? Or does this just indicate a burnt/worn clutch that needs replacing? Suggestions?
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Ralph in Socal
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Re: Stuck clutch pedal

Post by Ralph in Socal »

Series 2 cars have an eccentric bolt at the pedal to Master junction. Make sure the master is allowed to retract all the way back as that opens the inlet port and allows system pressure to drop back down.

Bently is specific about position of that bolt. It has a bump at the head and you're supposed to denote position before removal for reassembly

What's important is that the master is allowed to return back completely as that will release system pressure

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L.Tigre
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Re: Stuck clutch pedal

Post by L.Tigre »

Thanks for that advice, much appreciated.

It’s headed to the shop for major front-end work next week. I’ll ask my mechanic to take a look for that.
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Re: Stuck clutch pedal

Post by L.Tigre »

Update: mechanic took a look and reports that (i) the slave cylinder did indeed have a small leak, so he replaced it; and (ii) the clutch had not been replaced in a very long time and was basically shot. So, he replaced that also.
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