Clutch pedal not to floor - ZR-1 Net Registry Forums

Young1 · 06-27-2022

I finished my project car yesterday. Ready to take it out for a test drive and no start. Looking at it closely this morning the clutch pedal does not go all the way to the floor so most likely the clutch safety switch is not closing. But why does my clutch pedal not go completely to the floor after changing the clutch master cylinder? Did the pushrod possibly get disengaged somehow inside the master cylinder? This is not my first time putting one of these things in. The clutch pedal is probably 3/4 of an inch from hitting the floor. Any suggestions? I replaced the slave cylinder also.

owwdee · 06-27-2022

When changing the master cylinder was the spacer block reinstalled?

Young1 · 06-28-2022

Yes it was installed. I wonder if some electric connector got jammed up in the pedal mechanism up under the hush panel. Things were hanging all over when I put it back on.

richarde · 06-29-2022

Normally, the clutch pedal and brake pedal will sit at approximately the same height. If the clutch pedal stops 3/4 of an inch before hitting the floor, when released it should sit 3/4 of an inch above the brake pedal. If this happens, the possibilities are 1) clutch master cylinder spacer omitted (you have checked this and it is fitted), 2) clutch pushrod too short, 3) clutch master cylinder bore / stroke not to spec.
If the clutch pedal stops 3/4 of an inch above the floor but sits at the same height as the brake pedal when released, this suggests that the clutch slave cylinder may be reaching the end of it's stroke and causing the problem. Another possibility could be that the slave cylinder pushrod is not correctly mated to the clutch release arm. Or, the slave cylinder bore / stroke / push rod length is not to spec.
For reference, the clutch master cylinder bore is 11/16 of an inch (17.7mm) with a stroke of 27.5mm. The clutch slave cylinder bore is 1 and 1/16 of an inch (27mm). For every 25mm of clutch master cylinder movement, the clutch slave cylinder moves 10.75mm.
I hope this may help.

Sent from my iPad using ZR-1 Net Registry

Young1 · 07-01-2022

In morning I will crack open slave bleeder. If pedal goes to floor then my problem is the slave push rod got misplaced. If not then something has jammed the pedal. Will see.

Young1 · 07-02-2022

Slave push rod was misplaced. All is well.

Matt B · 07-02-2022

How can this be misplaced?

Young1 · 07-04-2022

64 years old, weak eyes, laying under car in 100 degree heat, covered in brake fluid from removing the old slave, wrong angle of dangle sliding it in, combined with a small portion of frustration the rod slid off the cup in the clutch arm.

-=Jeff=- · 07-04-2022

Quote:

Originally Posted by Young1

64 years old, weak eyes, laying under car in 100 degree heat, covered in brake fluid from removing the old slave, wrong angle of dangle sliding it in, combined with a small portion of frustration the rod slid off the cup in the clutch arm.

Your age doesn't matter, for the misplaced Slave rod, it is easy especially when the clip the holds it back prior to install is no longer doing its job..

Glad you found it and all symptoms would have pointed me to the slave rod as well

Matt B · 07-04-2022

Very interesting! Never thought about a potential issue when putting it back into position. I just slightly pulled mine during the backup switch replacement and obviously was lucky I didn't mess things up.

So, what needs to be considered to do the job right and avoid the misalignment?

06-27-2022	#1
Young1 Join Date: Sep 2016 Location: Ocala, FL Posts: 894	Clutch pedal not to floor I finished my project car yesterday. Ready to take it out for a test drive and no start. Looking at it closely this morning the clutch pedal does not go all the way to the floor so most likely the clutch safety switch is not closing. But why does my clutch pedal not go completely to the floor after changing the clutch master cylinder? Did the pushrod possibly get disengaged somehow inside the master cylinder? This is not my first time putting one of these things in. The clutch pedal is probably 3/4 of an inch from hitting the floor. Any suggestions? I replaced the slave cylinder also. __________________ Steve Young 1991 ZR-1 Quasar Blue Metallic/Black #729 Second Owner 1991 ZR-1 Dark Red Metallic/Black #2040 SOLD 1990 ZR-1 Dark Red Metallic/Saddle #1670 SOLD Double your happiness.....complain half as much.

06-27-2022	#2
owwdee Join Date: Dec 2015 Location: Colorado Posts: 69	Re: Clutch pedal not to floor When changing the master cylinder was the spacer block reinstalled? __________________ 1991 ZR-1 #1900 Black/Black

06-28-2022	#3
Young1 Join Date: Sep 2016 Location: Ocala, FL Posts: 894	Re: Clutch pedal not to floor Yes it was installed. I wonder if some electric connector got jammed up in the pedal mechanism up under the hush panel. Things were hanging all over when I put it back on. __________________ Steve Young 1991 ZR-1 Quasar Blue Metallic/Black #729 Second Owner 1991 ZR-1 Dark Red Metallic/Black #2040 SOLD 1990 ZR-1 Dark Red Metallic/Saddle #1670 SOLD Double your happiness.....complain half as much.

06-29-2022	#4
richarde Join Date: Sep 2012 Location: United Kingdom Posts: 68	Re: Clutch pedal not to floor Normally, the clutch pedal and brake pedal will sit at approximately the same height. If the clutch pedal stops 3/4 of an inch before hitting the floor, when released it should sit 3/4 of an inch above the brake pedal. If this happens, the possibilities are 1) clutch master cylinder spacer omitted (you have checked this and it is fitted), 2) clutch pushrod too short, 3) clutch master cylinder bore / stroke not to spec. If the clutch pedal stops 3/4 of an inch above the floor but sits at the same height as the brake pedal when released, this suggests that the clutch slave cylinder may be reaching the end of it's stroke and causing the problem. Another possibility could be that the slave cylinder pushrod is not correctly mated to the clutch release arm. Or, the slave cylinder bore / stroke / push rod length is not to spec. For reference, the clutch master cylinder bore is 11/16 of an inch (17.7mm) with a stroke of 27.5mm. The clutch slave cylinder bore is 1 and 1/16 of an inch (27mm). For every 25mm of clutch master cylinder movement, the clutch slave cylinder moves 10.75mm. I hope this may help. Sent from my iPad using ZR-1 Net Registry __________________ Richard 1990, numbers 1821 and 2391 1821 - owned since Nov 2002, charcoal / Gray, Stainless headers, B&B system, 4.10's 2391 - owned since Jan 2019, Black / Black, have completed restoration. Jeal headers, Corsa system, 4.10's, Aluminum flywheel with Carolina clutch.

07-01-2022	#5
Young1 Join Date: Sep 2016 Location: Ocala, FL Posts: 894	Re: Clutch pedal not to floor In morning I will crack open slave bleeder. If pedal goes to floor then my problem is the slave push rod got misplaced. If not then something has jammed the pedal. Will see. __________________ Steve Young 1991 ZR-1 Quasar Blue Metallic/Black #729 Second Owner 1991 ZR-1 Dark Red Metallic/Black #2040 SOLD 1990 ZR-1 Dark Red Metallic/Saddle #1670 SOLD Double your happiness.....complain half as much.

07-02-2022	#6
Young1 Join Date: Sep 2016 Location: Ocala, FL Posts: 894	Re: Clutch pedal not to floor Slave push rod was misplaced. All is well. __________________ Steve Young 1991 ZR-1 Quasar Blue Metallic/Black #729 Second Owner 1991 ZR-1 Dark Red Metallic/Black #2040 SOLD 1990 ZR-1 Dark Red Metallic/Saddle #1670 SOLD Double your happiness.....complain half as much.

07-02-2022	#7
Matt B Join Date: Jan 2021 Location: Beautiful Bavaria Posts: 523	Re: Clutch pedal not to floor How can this be misplaced? __________________ ZR-1 #638/1991

07-04-2022	#8
Young1 Join Date: Sep 2016 Location: Ocala, FL Posts: 894	Re: Clutch pedal not to floor 64 years old, weak eyes, laying under car in 100 degree heat, covered in brake fluid from removing the old slave, wrong angle of dangle sliding it in, combined with a small portion of frustration the rod slid off the cup in the clutch arm. __________________ Steve Young 1991 ZR-1 Quasar Blue Metallic/Black #729 Second Owner 1991 ZR-1 Dark Red Metallic/Black #2040 SOLD 1990 ZR-1 Dark Red Metallic/Saddle #1670 SOLD Double your happiness.....complain half as much.

07-04-2022	#10
Matt B Join Date: Jan 2021 Location: Beautiful Bavaria Posts: 523	Re: Clutch pedal not to floor Very interesting! Never thought about a potential issue when putting it back into position. I just slightly pulled mine during the backup switch replacement and obviously was lucky I didn't mess things up. So, what needs to be considered to do the job right and avoid the misalignment? __________________ ZR-1 #638/1991