The Truth about Adjustable Master Cylinders.

I have seen a lot of post about how Adjusting the master will help your tranny shift easier.
There are only two ways a properly operating master can affect the trannys operation.
One way is if you have the pedal set to engage right off the floor.
The master has a piston in it.
Weather it be a stock one or the Mcleod. This piston moves about an inch total.
That’s all that’s needed to disengage the clutch.
You need to leave yourself enough pedal travel to get this inch of piston travel.
If you have your pedal set too Low to the floor you will either, not disengage the clutch fully, or not at all.
An after marked clutch may be able to handle this better than the stock.
Reason being, The after markets tendency to be more of a binary clutch.
Meaning its more of an ON / OFF clutch.

The other way it can affect the Tranny is by having the pedal set too High.
With the pedal all the way up and hitting the stop or the switch, the Push rod going into the master should not have any pressure on it. The Pushrod should actually be what stops the upward Motion of the pedal.
The Piston inside the Master Has to reach its full up , or as I call it. It’s position of rest.
The reason here is, the pressure seal on the front of the piston HAS to come back far enough to clear the Holes leading up to the Reservoir. What happens here is, as your clutch wears down, the spring have to push back further, thus pushing on the slave and in turn pushes more fluid back to the master, This fluid it pushed up into the Reservoir. This is also true of Fluid getting warmer and expanding.
I hope this helps you understand the Master cylinder a little better.

 

Hmmm, that's very interesting.

So where do you think would be the perfect position to set the pedal at? I'm just curious because mine is adjusted all the way at the top of the pedal travel.

Ryan

 

I would say as Low as you can get it but still have enough pedal to get an inch of travel on the pushrod.

 

Don't mean to hijack the thread but, I use a centerforce dual friction, and a ripper pushed by stock hydrolics. I have been trying to figure out a problem for quite some time. My tranny shifts easily and smoothly anywhere below 5500rpm. Anything above that and it flat out wont come out or go into gear without 50lbs on the stick.. and grinds if I force it before slowing the engine a bit. I'm exagerating of course about the pressure it takes but I've heard several suggestions about it. It's not syrcros theyre new, it's not low or old fluids. It's almost as if the clutch isn't letting go in time. Again sorry for hijacking but I think there may be an answer to my hydrolic problem in here.

 

Yep
Thats why No one puts that POS centerforce clutch in thier car.
Dump that clutch and get you a Spec.
The centerforce sucks on our cars. Do a search for centerforce clutches , and you will see others with the same problem.
Tom

 

I was afraid of that. Should I try a new master and/or slave first?

 

yeah i had a centerforce clutch for 700mi w/adj master. HAD is the key word,i now have the ram 910 and it's an amazing set up.

 

I like everything about my centerforce except the most important thing, >6k shifting...

 

Thats why no one else wants them in thier cars.
A new master will not help. As far as I know.

 

I see. New clutch it is... boo for wasted cash..

 

Or you could re Cam your car so that it puts down Peak Hp and Torque around 5000 rpms LOL

 

I had the same prob. w/ my centerforce clutch....I'm about to upgrade to a spec i think.

 

Lol, right...?

Has anyone tried Centerforce about this? You can't adjust the plate for high rpms right?

 

My understanding of how the Centerforce clutch works is there are weights attached that fly outward with centrifugal force, making the clutch automatically hold tighter with increasing rpm. The problem with this is it makes it hard for the clutch to disengage at very high rpm. So in theory at least it may be possible to fix it by removing the weights or some weight off each of them.

 

I thought about that, and ask the people that installed it, but they didn't have a clue...

 

i've heard of people removing these weights off of the centerforce. weather or not it will help you i don't know, but it sounds like that could be your problem. however, if you're going to the trouble of pulling the tranny, i'd just go with a proven setup like the spec or ram clutches. JMO

 

I already ordered a Spec, I'm looking to get 3 or 4 tenths.

 

Great explanation of the hydraulics!

 

Anyone have a writeup on how to make the stock master adjustable?