Stiff clutch pedal question - Lateral-g Forums

Fluid Power · #1 04-14-2009, 04:10 PM

So I bleed the brakes and the clutch and holy leg work out Batman! The clutch is so stiff the car would be dangerous to drive. I am running a Tilton master cylinder and throwout bearing and the stock Camaro pedal setup. The pedal ratio is way out of whack given the mounting position of the MC and the stock pedals. (mental note to check ratio during initial mock up) So far, it seems my only option is to move and mount the master cylinder up higher, which given the firewall, (not smoothed) runs into some really crappy looks. I would then have to remotely mount the reservoir. This will change the pedal ratio which will decrease the pedal feel. Maybe I cannot see the forest for the trees, am I missing any other options????

Darren

**XcYZ** · #2 04-15-2009, 05:47 AM

Darren, how does the Clutch pushrod connect to the clutch pedal? I'm not up on the Tilton MC. Also, does Tilton offer MC's with different piston sizes?

Payton King · #3 04-15-2009, 06:00 AM

I know Gm's stock master for their LS1 style clutches is 7/8 bore. It sounds to me if you have the correct sized master for the Tilton unit you are running, the ratio is off.

Depending on the amount of room you have, you could weld a tab higher up on the pedal at the ratio you want and connect to that instead of the pedal itself to keep from moving the master up. I believe a 1st gen pedal is 13 inches long so to get a 6:1 ratio the master needs to connect 2 to 2.1 inches below the pivot point.

If the master is sized correctly and the ratio is correct and still having a stiff pedal...you have problems at the clutch and throwout.

Keep us posted

Fluid Power · #4 04-15-2009, 08:47 AM

The master cylinder is sized correctly for the throw out bearing (TOB) Tilton does make smaller bore size master cylinders, but the problem then becomes moving enough fluid to operate the TOB. It is a 7/8 bore, and I might be able to go to the 13/16, but again, the math doesn't improve much.

The push rod connects to the pedal via a rod end, so I have some flexibility to move it up a little more. I moved the rod end up a half an inch, which improves pedal ratio, but not enough to make much difference. I need the pedal ratio to be about 6 to 1 and I am about at 3.75 to 1.

I have been trying to figure out a 'Rube Goldberg' way to move the rod and not have to move the MC.

Keep the ideas coming!

Payton King · #5 04-15-2009, 10:22 AM

It would not improve that much even if you went to a 5/8's.

I would build a new mount on the fire wall in the shape of a wedge that angled the master so the push rod hit the pedal where it needs to go. You will also need to run the remote res since it will be angled down. You could always make a trick looking mount for the res that covered the wedge looking spacer.

Does this make sense?

**GregWeld** · #6 04-16-2009, 05:18 PM

You have to bite the bullet and do it right --- or it's always going to bug you and be a problem...

I hate stuff like that - but it's one of those "live and learn" lessons...

I'm sorry for you - but we've all been there and done that - on various items at one time or another!

:>(

asifnyc · #7 04-17-2009, 12:15 AM

I had a similar problem and I'm finally doing something about it. I'm relocating my master high on the firewall so that the rod can be near the top of the clutch pedal arm. I'm running a power brake booster though. to deal with the interference problem I created a clutch "box" to bring the master "into" the car a couple of inches. you can see the picks of my butchery on my blog http://asifnyc.com. look for the two recent posts titled "clutch box" and "adventures of clutch box". probably won't pass your "looks" test but just thought I'd mention it since I know this is going to solve my heavy pedal problems...

Fluid Power · #8 04-17-2009, 04:42 AM

I never intended not to fix the problem, just wanted to see if there were any creative ways to fix the issue! I chaulk this one up to assumption. I assumed it would work, instead of researching it to death like I do everything else.

asifnyc: Great idea! This might work for me as well. I might have to do some touch up on the fire wall....I need to spend some time this weekend thinking this thru. Thanks a lot!

Darren

**GregWeld** · #9 04-17-2009, 06:56 AM

Chop, Cut, Rebuild.... :>)

asifnyc -- Kudos! Good job and good fix!

This is a classic example of why we build our cars in the "raw".... and why we build them - what - about 15 times? LOL

Fluid Power · #10 04-17-2009, 11:16 AM

Quote:

Originally Posted by GregWeld

Chop, Cut, Rebuild.... :>)

asifnyc -- Kudos! Good job and good fix!

This is a classic example of why we build our cars in the "raw".... and why we build them - what - about 15 times? LOL

Yep, exactly, I mocked everything up, never thought to grab the tape measure and run some calculations to determine the ratio...Oh well, wouldn't be the first time I have done something twenty times....

Darren