Clutch Pedal Drops To Floor

tom_sprecher

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Over a period of time the clutch pedal drops to the floor making shifting difficult. It is only at that time I notice the pedal height. I reach my foot behind the pedal and pull it up into position. You can feel resistance like the master cylinder piston is filling back up. Then everything works fine. The pedal feels weird because I have to get used to it being up, but after a couple of minutes it's all good.

This has randomly happened twice in 3 months. There is no fluid loss. Any ideas? Sticky return valve in the master cylinder piston?





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ctandc72

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I would check the clutch master cylinder line and see if it's seated all the way. There is a thread here with pictures. Would post the link but on mobile...sorry.
 
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Where is the clutch master cylinder? I can see the line from the brake master reservoir go into the firewall and that's about it. Don't tell me it's inside the car. :mad:
 
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That thread is 15 pages about the line that runs from the brake fluid reservoir to the master cylinder. Specifically where the line attaches to the reservoir coming loose. It says nothing about the master cylinder.

A couple of posts talk about the slave cylinder dying after a day at the track.
 

ctandc72

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That thread is 15 pages about the line that runs from the brake fluid reservoir to the master cylinder. Specifically where the line attaches to the reservoir coming loose. It says nothing about the master cylinder.

A couple of posts talk about the slave cylinder dying after a day at the track.
If the line isn't seated, air will get into the clutch system. Check the line. Look at the pictures on the first post it shows how it should look and how it looks if not seated all the way.
 

EastTNMustang

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That thread is 15 pages about the line that runs from the brake fluid reservoir to the master cylinder. Specifically where the line attaches to the reservoir coming loose. It says nothing about the master cylinder.

A couple of posts talk about the slave cylinder dying after a day at the track.
Ok...I’m glad I could help ;)
 
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tom_sprecher

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If the line isn't seated, air will get into the clutch system. Check the line. Look at the pictures on the first post it shows how it should look and how it looks if not seated all the way.
I saw that thread when it first came out and checked back then. It was seated then and is now. Also there is no leaking of brake fluid at that connector.

Besides if air was getting into the system at that point simply pulling up on the clutch pedal would not eliminate it. If anything it would make it worse by having the vacuum of the master cylinder piston pulling air into the cylinder instead of brake fluid. As soon as I pull up on it I get a firm pedal which is not the sign of air in the system.

I appreciate the suggestions, but it's just frustrating. :confused:
 
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Lime1GT

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Yes, the clutch master cylinder is under the dash. If you have to change it you have to remove the clutch pedal assembly first. Check your brake reservoir fluid; is it to the full line? The clutch master cylinder will run low on fluid well before the brake system does. Look for leaks under the car indicating a clutch slave cylinder or line leak. Check under the dash around clutch master cylinder area for brake fluid on carpet indicating a clutch master cylinder leak. Check for broken welds on clutch pedal linkage. Just a few suggestions.
 
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As a follow-up the clutch master cylinder was just replaced under warranty. They even removed the transmission to make sure the slave cylinder was not at fault.
 

coltelee

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As a follow-up the clutch master cylinder was just replaced under warranty. They even removed the transmission to make sure the slave cylinder was not at fault.
Did you ever figure out the problem? I just purchased a 2015 Ford Mustang GT and am having the same issues.
 
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Like it said in the quote it was the clutch master cylinder was bad.
 

Arknsawchuck

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Where is the clutch master cylinder? I can see the line from the brake master reservoir go into the firewall and that's about it. Don't tell me it's inside the car. :mad:
The brake res and clutch res are one and the same. My guess is a line issue or air in the system.
 
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The brake res and clutch res are one and the same. My guess is a line issue or air in the system.
It was the clutch master. Read the OP and you will see that the symptoms have nothing to do with air in the line.

This is a case where the pedal slowly drops to the floor over 3-4 weeks where you do not notice it until it does not allow the clutch to fully disengage. Fluid was getting past the master cylinder piston seal.
 

Arknsawchuck

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It was the clutch master. Read the OP and you will see that the symptoms have nothing to do with air in the line.

This is a case where the pedal slowly drops to the floor over 3-4 weeks where you do not notice it until it does not allow the clutch to fully disengage. Fluid was getting past the master cylinder piston seal.
Ok, cool. Glad the OP figured it out. Sometimes I guess wrong...lol. And I learned something too, so a win, win.
 

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