clutch master cylinder and slave

[HaWiiLuVeR]

ive posted here a couple times before, but not for a while. ive got a 69 charger with a 440 that i made an adapter to put a t56 behind it. im using a weber 12" alum flywheel and clutch setup, and the viper slave/TO to disengage the clutch. im also using the factory master cylinder to feed the slave, and i dont think its displacing enough fluid to fully disengaged the clutch.

i was wondering if anyone on this board would know the bore and stroke of the master cylinder. i am looking at getting a wilwood master cylinder, but need to know what size the factory is first. are there any bolt-on upgrades to increase the fluid of the stock viper system?

thanks for your time and help.

 

[Warren 00 GTS]

Bore and Stroke 27.0 mm X 32.17mm (1.06 in. X 1.26 in)

 

[HaWiiLuVeR]

thanks for the quick and informative reply.

another question i forgot to ask...

i have seen fittings that go into the slave cylinder and adapt it to AN fittings. anyone know who makes that piece?

 

[Bill B]

Aeroquip has them.

 

[David Jenkins]

It should be able to work. Are you sure the throw out bearing isn't too far away from the pressure plate? How much stroke do you need to compress the fingers? Can you see in the bellhousing to watch the throw out while someone actuates it?dj

 

[HaWiiLuVeR]

i cant see into the bellhousing because i have no inspection cover. i had to machine a solid aluminum adapter for the trans to mate to the 440. its 1.5" thick because the input shaft of the trans was very long.

my problem is that if i pause in nuetral for too long, the internals will start spinning and will make 1st gear grind when i go into that gear. i think part of it is that synchro is toasted, but also the clutch not disengaging entirely.

im not sure how much travel is required to disengage the clutch. its a 12" diaphram style weber clutch.

 

[Tom F&L GoR]

I learned something that may or may not apply here. Unlike a "mechanical" clutch linkage system, where there is some free play and the release bearing is *not* riding on the pressure plate fingers, in a hydraulic clutch system the release bearing is *always* riding on the fingers. There's a spring that's part of the bearing assembly to keep the bearing against the pressure plate fingers. Think about it - there's no retraction method to pull the bearing off the fingers. If the set up is trying to accomodate some clearance, maybe that's where the problem is? I dunno, just a thought.

 

[HaWiiLuVeR]

tom, what you are saying is correct. the TO bearing has a spring to push it into the pressure plate to basically pick up the slack.

could this problem be a faulty master cylinder? maybe all i need is a new unit?

 

[Tom F&L GoR]

I think you're stuck having to find out if the travel needed for the Viper pressure plate is the same as for the 1" Weber. If you need lots more travel, then you'll need a different MC.

I found the OEM Viper travel a little short, so I welded another pin onto the clutch pedal swing arm; about 0.5" lower towards the pedal. (The pin where the MC attaches to the pedal arm.) Yes, it's harder to push, but in any adrenaline moment, you won't notice. The slave travel is now proportionally longer also, and now I only dip into the pedal and I can shift.

I think these numbers are at least close: pedal to rod on which it swings-8"; rod to old pin-2"; rod to new pin-2.5" So now my travel at slave is now a ratio of 8/2.5 (3.2:1) instead of 8/2 (4:1) or 25% more travel (and stiffness.)

 

[HaWiiLuVeR]

when i mounted the MC, i made sure to get the full travel of the rod on the clutch pedal swing. i dont recall the measurements, but i know for sure that the rod is traveling to the end.

thanks for all your help, im going to have to get in there somehow i guess.