Clutch master stroke length?
Thread Starter
Le Mans Master
Joined: Dec 2002
Posts: 5,270
Likes: 3
From: Seattle Area WA
Clutch master stroke length?
From what I can tell, the stock clutch master bore is 11/16".
I cannot find anything where the stroke is listed.
I'm away from the car so I can't even look at that to attempt to figure it out.
Anybody know?
Thanks in advance.
The car is a 1986, not sure if that makes a difference.
I cannot find anything where the stroke is listed.
I'm away from the car so I can't even look at that to attempt to figure it out.
Anybody know?
Thanks in advance.
The car is a 1986, not sure if that makes a difference.
Thread Starter
Le Mans Master
Joined: Dec 2002
Posts: 5,270
Likes: 3
From: Seattle Area WA
Prepping to change out all the hydraulics for a trans swap and I need to calculate the volume of fluid the master pushes.
I know the diameter is 11/16" I just need know how much the master pushrod travels so I can determine the volume the master pushes to make sure I have enough push for my slave. I think you could determine this by measuring the distance the master eyelet/top of clutch pedal travels but I was hoping somebody had this knowledge on hand.
I grew up in Tri-Cities, how's Spokane now? Getting warm yet?
I know the diameter is 11/16" I just need know how much the master pushrod travels so I can determine the volume the master pushes to make sure I have enough push for my slave. I think you could determine this by measuring the distance the master eyelet/top of clutch pedal travels but I was hoping somebody had this knowledge on hand.
I grew up in Tri-Cities, how's Spokane now? Getting warm yet?
Drifting
Joined: May 2006
Posts: 1,428
Likes: 7
From: Chewelah Wa
Ahh I see....I guess I can't help ya on that one. As far as the weather goes, it has snowed just about everyday, the temp FINALLY hit 60 degrees on Sunday (new record for the latest this has happened), then went right back to cold and snow. It was 38 degrees in the afternoon 2 days ago. The weather has been crap since the end of last October (early winter, also). Thanks for asking lol 
Melting Slicks
Joined: Jan 2009
Posts: 3,482
Likes: 196
From: folsom california
clutch piston travel ? limitless.
speaking of my 96...which I assume is similiar to your year, what limits the piston travel is when the clutch pedal bottoms out against the firewall / rug
the total available travel; i.e. length of the bore, on my car was 39 mm; the factory linkage utilized 16mm of travel before the clutch pedal bottomed out.
there's a spacer between the (front) of the firewall and the master cylinder; the thinner this spacer becomes, the farther up (towards the driver) that the pedal moves; this in turn allows utilizing a greater stroke in the master cylinder bore.
Stock, my clutch pedal was always lower than the brake pedal, clumsy at best. I substituted a thinner spacer, approximately half the thickness of the stock spacer, which brought the pedal up even with the brake pedal (and no, my clutch pedal arm was not bent, and all the bushings were new, etc.).
at that point I had a stroke of 28.5 mm.
good luck...clutch set ups can be tricky with these cars..but when they work, they work great, as mine does now.
p.s. use fluid thicker than dot 3; I prefer dot 5.
speaking of my 96...which I assume is similiar to your year, what limits the piston travel is when the clutch pedal bottoms out against the firewall / rug
the total available travel; i.e. length of the bore, on my car was 39 mm; the factory linkage utilized 16mm of travel before the clutch pedal bottomed out.
there's a spacer between the (front) of the firewall and the master cylinder; the thinner this spacer becomes, the farther up (towards the driver) that the pedal moves; this in turn allows utilizing a greater stroke in the master cylinder bore.
Stock, my clutch pedal was always lower than the brake pedal, clumsy at best. I substituted a thinner spacer, approximately half the thickness of the stock spacer, which brought the pedal up even with the brake pedal (and no, my clutch pedal arm was not bent, and all the bushings were new, etc.).
at that point I had a stroke of 28.5 mm.
good luck...clutch set ups can be tricky with these cars..but when they work, they work great, as mine does now.
p.s. use fluid thicker than dot 3; I prefer dot 5.
Thread Starter
Le Mans Master
Joined: Dec 2002
Posts: 5,270
Likes: 3
From: Seattle Area WA
Ugh, I typed out a long response and it got lost.
Anyway, much thanks mtwoolford! Albeit a 96, I would hope that these results are about similar on earlier hydraulics. Time will tell when I finally get back to the car and can attempt this.
I'll be doing the zf6 swap but with a hydraulic TOB. The one I'm using has a max 0.549, the master according to your 39mm (1.535") provides a max of 0.558 for this TOB or 0.009" in excess travel. I'd bet that isn't enough to blow the o-ring but regardless if it is anything more like your stock or better yet 28.5mm setup it should have perfect throw with clutch release point probably in the bottom of the first 1/2 of throw but before midway. We'll see I suppose, depends on how much action my PP requires but for now, I'm confident the 11/16" master should work and may actually be much easier and safer than attempting an upgrade. Fingers crossed. I'll do a big update when I know for sure.
Thanks again.
Anyway, much thanks mtwoolford! Albeit a 96, I would hope that these results are about similar on earlier hydraulics. Time will tell when I finally get back to the car and can attempt this.
I'll be doing the zf6 swap but with a hydraulic TOB. The one I'm using has a max 0.549, the master according to your 39mm (1.535") provides a max of 0.558 for this TOB or 0.009" in excess travel. I'd bet that isn't enough to blow the o-ring but regardless if it is anything more like your stock or better yet 28.5mm setup it should have perfect throw with clutch release point probably in the bottom of the first 1/2 of throw but before midway. We'll see I suppose, depends on how much action my PP requires but for now, I'm confident the 11/16" master should work and may actually be much easier and safer than attempting an upgrade. Fingers crossed. I'll do a big update when I know for sure.
Thanks again.
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