Hydraulic Clutch, This works GREAT! Options

[IronHillRestorations]

I ran the hydraulic line through the clutch tube. The only issue I ran into was heat from the exhaust system cooking the seals in the slave cylinder. I made a heat shield and wrapped the heat exchangers.

[dfelz]

The exact diameter is not very important, just that the master and slave diameters should match. As he said, 3/4" is easy to get ahold of and use.

WEVO is Windrush Evolutions, and they make (among other things) a shifter base that Paul is using.

--DD

Ok thanks. At the moment i am planning on using a Howe pull type slave cylinder with a tilton 76-series MC (I have both a 13/16" and 1" bore), so since the howe says best use with a 3/4" MC should i use the 13/16" bore MC i have, since thats closest?

[euro911]

David, as long as ID is the same in both cylinders, you'll maintain a 1:1 ratio.

I so much want to do this (IMG:style_emoticons/default/smile.gif)

[Elliot Cannon]

Well, that's just great! I get started on one big project and another comes along. (IMG:style_emoticons/default/laugh.gif)

[76-914]

Well, that's just great! I get started on one big project and another comes along. (IMG:style_emoticons/default/laugh.gif)

Man, do I know that feeling! (IMG:style_emoticons/default/chair.gif)

[charliew]

Good info and pictures. I like having two reserviors as if one system leaks at least the resiorvor won't get drained. I will be using the wrx tranny with a performance pressure plate so the pedal pressure will be more and the hydraulic cylinder is already on the suby tranny so this is good stuff to me. I never though about the clutch tube but it seems logical. Somehow I missed this thread or the paint fumes erased it for me.

I have equal length headers on a v6 fiero and the heat can be felt in the pedal feel on a 105 degree day.

[Mark Henry]

Of course I'm looking to do this with cheaper and more common parts from my local FLAPS (IMG:style_emoticons/default/smile.gif)

I can use a common Dorman 3/4" master cylinder for $35, but I haven't found a car that uses a pull style slave yet.
I can get a Dorman push style slave for $18.

[skeates]

I'm curious how the clutch pedal was modified for a return spring? It looks like the stock return spring is disconnected (makes sense since it would be pulling the clutch pedal to engage the clutch) and another spring added onto the clutch pedal. With the hydraulic set-up how important is a clutch return spring?

[PRS914-6]

I'm curious how the clutch pedal was modified for a return spring? It looks like the stock return spring is disconnected (makes sense since it would be pulling the clutch pedal to engage the clutch) and another spring added onto the clutch pedal. With the hydraulic set-up how important is a clutch return spring?

The pic was taken during the prototype process and the spring was ultimately removed. You don't want downward pressure with a hydraulic system. The stock spring pushes down and is NOT a return spring. Like brakes, you want the master cylinder piston to completely retract allowing the internal port to be exposed at rest.

On my 915, there is enough spring to push everything back properly.

As a side note......if you do this system, make sure the push-rod you make that is attached to the pedal has a small amount of clearance between the rod and the master cylinder piston at rest (again to keep the internal port open)

[skeates]

I'm curious how the clutch pedal was modified for a return spring? It looks like the stock return spring is disconnected (makes sense since it would be pulling the clutch pedal to engage the clutch) and another spring added onto the clutch pedal. With the hydraulic set-up how important is a clutch return spring?

The pic was taken during the prototype process and the spring was ultimately removed. You don't want downward pressure with a hydraulic system. The stock spring pushes down and is NOT a return spring. Like brakes, you want the master cylinder piston to completely retract allowing the internal port to be exposed at rest.

On my 915, there is enough spring to push everything back properly.

As a side note......if you do this system, make sure the push-rod you make that is attached to the pedal has a small amount of clearance between the rod and the master cylinder piston at rest (again to keep the internal port open)

Thanks for the response! You are correct - the stock clutch pedal spring adds some pre-load to the clutch cable and I can certainly understand why it would be removed for the hydraulic set-up. I had "return spring" in my head at the time and used it without thinking.

It sounds like with the 915 transmission one can get away with not adding a return spring to the clutch pedal when doing this conversion. I'm planning on using a Subaru transmission in my project and haven't seen much detail in the suby conversion threads on this subject. I noticed that in the original pictures (at the start of the thread) a return spring had been added to the clutch in the background so I thought I'd ask the question. BTW Great set-up PRS914-6!

[02loftsmoor]

do realize your though out bearing will be always incontact with the clutch release fingers, thus always loaded

[Dave_Darling]

The stock one is as well. So?

--DD

[tscrihfield]

Resurrecting this thread because it is awesome. Planning a lot of work on the old girl this winter and this is high on the list.

[strawman]

On my Suby-swapped 914, I'm using a Honda Civic master cylinder on a custom forward firewall mount and the stock Suby slave cylinder on the Suby transaxle. Details are sprinkled throughout my build thread. Works great!