Clutch master cyliner linkage

[John S]

I'm in the process of mocking up the mc in my Monte and am having some difficulty with the pushrod setup. With the mc mounted the pushrod aligns very low on the pedal, so low that I would see about 8" of travel which is way too much. Without geeting to extreme with linkanges and such is it possible to use a section of rod with a "Z" bend in it to install higher up on the pedal arm then align with the mc pushrod?
Will the Z rod have a tendancy to twist? Also I know the linkage movement should be as straight as possible into the MC, how much toerance is acceptable?
Any other thoughts and ideas on hooking this up are greatly appreciated.

The MC mounted to the firewall.

[parsonsj]

John,

You need to think in "pedal ratios". A good place to start is 6:1. 6 inches of pedal pad travel equals 1" of pushrod travel.

I think you're going to have to find a way to move the MC higher on the firewall. A Zbar can change the height of the pushrod, but it also reverses the direction too. You'd need a "double Z" or some such.

jp

[HILROD]

The stock Camaro clutch master mounts almost exactly to the hole that was, is behind your aluminun plate. The cyl. is tilted upwards so it'll mount higher on the pedal for less travel. You might be able to angle the master you have?

[RatMalibu]

john....here's my solution to the same exact dilemma





I was going hydroboost anyway so i made myself a plate to mount both of them side by side

[John S]

Matt; Great idea and nice work. Unfortunatley my wiper motor sits very close to the hydroboost and it may be difficult to make the same mount. I may be able to do some trimming of the wiper motor mount and make it work. At least it's another possibility to explore.

[RatMalibu]

John the firewalls are pretty much identical between our cars... I bent the edge of the wiper mounting panel over just a bit and have 1/4" or so between my plate and the panel....the hole for the clutch master is cut through the part that angles off and away from the flat mounting portion where the original booster mounts....the rubber boot for the master seals it up nicely though (just don't cut the hole too big)

here's a pic of the firewall

[John S]

Matt;
you're right. I've been looking over everything for a while tonight and cutting through right on that angle section is the way to go. Did your hydroboost come mounted to a thick billet plate? Mine is mounted on a 3/4" billet mounting plate and I wonder if I can do away with it. No matter I will need to seperate it from the booster to flip it over so the nitrogen charge is on the opposite side away from the clutch MC.

[RatMalibu]

no mine is a factory unit that i made the plate for....its 3/16" plate (the same as the factory plate) it was fairly easy to make I mocked it up with a hunk of 1/4 plywood then had a buddy cut me out a chunk of plate at the metal shop he has access to...used a 1 5/8" hole saw for the hydroboost hole and a 1 1/2" hole saw for the MC hole.....I cut the HB hole first then took the pushrod out of the MC (snap ring under boot, carefull its spring loaded lol) and kinda put it where i thought it should be and drilled that hole. I had a factory plate to use for parts so I pressed the studs out and pressed them into my plate. welded a couple studs in for the MC....made a 1" box on the clutch pedal and an adjustable pedal stop

all with a hack saw, grinder, and a mig

hope to have it mobile again in the next few weeks (my headers are off being coated)

[John S]

Matt;
What type of mounting nut is on the oem style HB? I spoke with Paul at hydratech today and if I wnat to rotate my unit he said I will need to send it in. The only problem is that I want to make some changes to the mounting late as well and I would end up having to ship things back and forth a couple of times to do it. If I can do it myself it will save me some time and money.

[RatMalibu]

its a big 4 sided nut with some teeth on the mounting face....i used a hammer and a small chisel to take it off and put it back on

[Hurst - Jeff]

The most important thing is to mount the clutch pedal push rod at the correct place on the pedal. As was previously stated you want to use a 6:1 ratio - in other words in your clutch pedal is 12" long from pivot point to pedal, you would want to mount the push rod 2" +/- down from the pivot point. Our new hydraulic system puts the rod 2.25" down from the pivot point for the master cylinder push rod. The mc is mounted at an angle.
If the push rod is too low on the pedal, your pedal stroke to engage/disenage wil be awkwardly short and the pedal pressure will be way too heavy.
If you mount to high on the pedal, your pedal effort will be very easy but you will not have enough travel to release the clutch.

Getting hydraulics to work correctly and reliably in older muscle cars has been one of the more challenging efforts for us when designing new products.

Make sure to use the correct bore size mc that is designed to work with your TO bearing.
We are using a short bodied 7/8" bore, 1" stroke unit and it works great - the pedal feels the best that I have felt a hydraulic pedal feel in an older car.

[John S]

Jeff;
I know most are calling for a 6:1 ratio. The mfg of the mc I have is recommending 5:1, do you see any issues with this?
I fabbed up a mounting plate similar to Matt's but slotted the mounting holes so that I will have some degree of adjustability.

[Hurst - Jeff]

Do what the manufacturer says because they should know their own product best.
5:1 on a 12" pedal would put you at 2.5" below the pivot point. You will likley be fine with this. If your pedal ends up too stiff, you may need/want to move it closer to the pivot point.

[John S]

Here is the plate that I fabbed up to mount the MC. I've still got some finish work to do like rotate the hydroboost mounting plate and re route the hoses. But this should work very nicely. Thanks again matt.

SO here is what I did...

[RatMalibu]

glad I could help, you'll want to stick the fuse box back in the car and make sure you've got clearance there too before you finalize...its tight but totally possible..mine clears