Q on the clutch pedal

sv51macross · 10-26-2010, 11:03 PM

Well, this seemed like the least-unfit section to post this. For awhile, the clutch had a soft feel to it, and attempts at bleeding the slave yielded sputtering and spitting now matter how much was bled, the screw just didn't work right. So fast forward a few months and I'm driving home from class at an exuberant rate, and the clutch pedal sticks to the floor. After promptly crapping myself, I pull over and free the pedal from the phantom catching. I thought that one or both cylinders in the clutch circuit were going, but the sticking pedal has not returned (albeit no spirited driving) and after adjusting the slack out of the pedal, it feels nice and firm.

Someone on RX7club.com posted on another person asking about a similar experience and said that a maladjusted pedal could cause it to stick...any truth to this? It's approaching two weeks since it happened, and the clutch pedal hasn't stuck since.

RotaryDiagnostics · 10-27-2010, 06:37 AM

Quote:

Originally Posted by sv51macross

Someone on RX7club.com posted on another person asking about a similar experience and said that a maladjusted pedal could cause it to stick...any truth to this? It's approaching two weeks since it happened, and the clutch pedal hasn't stuck since.

I doubt it. Most likely a problem with the clutch master cylinder internal seal allowing the fluid to intermittently "leak" past the seal when depressing the pedal. Replace the master, and slave while you're at it, and bleed the system.

Buggy · 10-27-2010, 09:05 AM

+1 FC clutch master cylinders suck. I've had 2 fail on me in the past and the one in my Rx-4 as well. That will be the cause of the problem. Also replace the slave cylinder too incase any debris from the clutch master got into it. Check your flex hose as well. All of these parts are now old and the rubber just fails.

braggy_g2 · 11-01-2010, 12:28 AM

I agree with above post.
You need to check for leaks on both Master Cylinders and Release Cylinders and hoses.
If one of the cylinders are worn, it is best to replace both Master and Release Cylinders.

It happend to me.
In 2006 I replaced the Release Cylinder then all of a sudden the next year the Master Cylinder gave up and was leaking badly.

***TitaniumTT*** · 11-01-2010, 05:18 AM

Master is on it's way out. Happens every year when the weather turns cold, the hyrdo's start to fail.

rx4ur7 · 11-02-2010, 03:50 PM

TT is correct. Clutch pedal staying to floor is internal fluid bypass in the master. OH or renew. If you use a Mazda kit and the bore is not rusted/pitted it can be honed and used for another 100K as long as you change the fluid every 3year or 30K miles for normal driving conditions.
Biggest problem with Brake and clutch systems is that no one changes the fluid. As fluid gets old and dirty it has a tendency to absorb even more moisture, which settles at the bottom of the cylinders, rusting them, damaging the cups.
As I tell all my clients, brake fluid is cheaper than masters, slaves, calipers and cylinders. (that way we can put more money into the motor when it comes time)

10-26-2010, 11:03 PM	#1
sv51macross Rotary Fan in Training Join Date: Oct 2010 Location: Ann Arbor, Mi iTrader: (0) Posts: 47 Rep Power: 0	Q on the clutch pedal Well, this seemed like the least-unfit section to post this. For awhile, the clutch had a soft feel to it, and attempts at bleeding the slave yielded sputtering and spitting now matter how much was bled, the screw just didn't work right. So fast forward a few months and I'm driving home from class at an exuberant rate, and the clutch pedal sticks to the floor. After promptly crapping myself, I pull over and free the pedal from the phantom catching. I thought that one or both cylinders in the clutch circuit were going, but the sticking pedal has not returned (albeit no spirited driving) and after adjusting the slack out of the pedal, it feels nice and firm. Someone on RX7club.com posted on another person asking about a similar experience and said that a maladjusted pedal could cause it to stick...any truth to this? It's approaching two weeks since it happened, and the clutch pedal hasn't stuck since. __________________ 1990 Mazda RX-7 NA; Lucy, after the main antagonist from Elfin Lied. Eventual plans? Something cyberpunk and spicy.

10-27-2010, 09:05 AM	#3
Buggy I've been Wankeled! Join Date: Apr 2010 Location: Mildmay, Ontario, Canada iTrader: (0) Posts: 260 Rep Power: 15	+1 FC clutch master cylinders suck. I've had 2 fail on me in the past and the one in my Rx-4 as well. That will be the cause of the problem. Also replace the slave cylinder too incase any debris from the clutch master got into it. Check your flex hose as well. All of these parts are now old and the rubber just fails. __________________ 1976 Rx-4 hardtop. Half bridge 3B 13B, S5 NA rotors, Renesis e-shaft, stat gears, and bearings, balanced rotating assembly, RE dual weber 36 DCD's 203rwhp 137ft-lbs torque DGRR 2011 3rd place 1974 Rx-4 all original 27,000 miles 1988 Rx-7 TII 320rwhp. DGRR 2012 3rd place

11-01-2010, 05:18 AM	#5
*TitaniumTT* Test Whore - Admin Join Date: Mar 2008 Location: Right Behind you son iTrader: (4) Posts: 4,581 Rep Power: 10	Master is on it's way out. Happens every year when the weather turns cold, the hyrdo's start to fail. __________________ -The Angry Stig- DGRR 2009, 2011, 2012 & 2013 - Best FC DEALS GAP!! WOOHOOOO!!!!! 2015 Audi S4 - Samantha - Zero Brap S4 2004 RX8 - Jocelyn - 196rwhp, 19mpg fuel to noise converter 2000 Jeep Cherokee Sport - Wifey mobile - Now with 2.5" OME lift and 30" BFG AT KO's! So it begins 1998 Jeep Cherokee - 5 spd, 4" lift, 33" BFG's - Rotary Tow Vehicle 1988 'Vert - In progress 1988 FC Coupe - Gretchen -The attention whore BEAST! I'm a sick individual, what's wrong with you? I'm pure Evil I'm still insane, in the best possible way. I think Brian's idea of romance is using lube. Your rage caused the meteor strike in Russia. The Antichrist would be proud of his minion. You win with your thread. Most everything It's a truck with a steel gate on the back. Just a statement of fact Motec M820, AIM dash, ported 13B-RE Cosmo, 6-spd trans, 4.3 Torsen, custom twin wg fully divided mani, Custom 4" split into 2x 3" exhaust, Custom HMIC, Custom custom custom custom I like to welder stuff.... No Bolt-ons allowed. Dyno'ed @ Speed1 Tuned by me - 405rwhp on WG.... WM50 cuming soon. *-Angry Motherfcker Mode ENGAGED-**

11-01-2010, 12:28 AM	#4
braggy_g2 The Newbie Join Date: Oct 2010 iTrader: (0) Posts: 2 Rep Power: 0	I agree with above post. You need to check for leaks on both Master Cylinders and Release Cylinders and hoses. If one of the cylinders are worn, it is best to replace both Master and Release Cylinders. It happend to me. In 2006 I replaced the Release Cylinder then all of a sudden the next year the Master Cylinder gave up and was leaking badly.

11-02-2010, 03:50 PM	#6
rx4ur7 Rotary since 1972 Join Date: Nov 2008 Location: Tucson iTrader: (0) Posts: 231 Rep Power: 17	TT is correct. Clutch pedal staying to floor is internal fluid bypass in the master. OH or renew. If you use a Mazda kit and the bore is not rusted/pitted it can be honed and used for another 100K as long as you change the fluid every 3year or 30K miles for normal driving conditions. Biggest problem with Brake and clutch systems is that no one changes the fluid. As fluid gets old and dirty it has a tendency to absorb even more moisture, which settles at the bottom of the cylinders, rusting them, damaging the cups. As I tell all my clients, brake fluid is cheaper than masters, slaves, calipers and cylinders. (that way we can put more money into the motor when it comes time)