Effort Reduction Kit

Hello again Mikael. As I already mentioned in my opinion a Master Cylinder MC is completely blind and has no clue what is pushing it to its bottom/full stroke. From stop to stop a MC moves a certain volume of fluid. Since a ERK also moves the piston in the MC from zero to full stroke it moves exactly the same volume of fluid and hence has the same impact on the slave stroke provided every other components are the same.

quote:

ello again Mikael. As I already mentioned in my opinion a Master Cylinder MC is completely blind and has no clue what is pushing it to its bottom/full stroke. From stop to stop a MC moves a certain volume of fluid. Since a ERK also moves the piston in the MC from zero to full stroke it moves exactly the same volume of fluid and hence has the same impact on the slave stroke provided every other components are the same.

Hello Jan
I agree with the first sentences. But the issue is that you can't have the clutch pedal move as without an ERK, and then expect it to be able to move the piston in the same length in the MC. It's just like your bicycle, you can reduce your effort by changing into a lower gear, but then you also go less distance per pedal revolution, right? There's no gear on your bike that makes it easier to go uphill (less effort required) but will still get you as far per revolution. Because it's not physically possible. Arm/length/force constant

Any engineers out there? Please?

To my understanding the ERK is not a matter of less travel of the rod that pushes into the MC but rather moving the "balance" point of where the effort is applied to match the effort required and the angle of your leg/knee so that initially actually more effort is required but as the pedal approaches the floor (and full stroke on MC) the effort required becomes less du to the geometry of the ERK. Enough travel of MC and slave is so essential/marginal that I find it difficult to accept that DeTomaso compromised that by introducing the ERK.

Mikael are you saying that with my ERK I am not able to press the MC to its full stroke? My pedal stops a few cm above the floor by what I believed was the MC bottoming out!

maybe I got it all wrong??

I find this an interesting can of worms that Mikael has introduced. If the Master's pushrod is traveling the same distance on each stroke, then you are passing identical fluid amounts to the slave. So, does the Effort reduction kit shorten the stroke or doesn it increase clutch pedal travel. If the later, goodroc got it right. If the former, Mikael. I concur with Mikael that their is no free lunch and I am hoping the compromise is increased pedal travel. Admittedly, I don't know the answer.
Unfortunately Doug, I believe that your adjustment technique won't work.

From ProvaMo:

"This change in the linkage assembly adds a number of parts that together change the geometry such that some of the perceived pedal effort is moved from the beginning part of the pedal travel (top) to near the bottom of the pedal travel (nearer the floor). It is perceived as easier because the leg has more leverage when the pedal is closer to the floor."

I throw out a quick answer as I don't have time at the moment to do a good explaination.

In jest, the ERK is a "4 bar" device
https://www.youtube.com/watch?v=Vh8r_Cpfb8Q
http://bdml.stanford.edu/twiki.../Rise/LegDesign.html

this provides a non linear output of the MC as the input pedal is depressed.

as stated, if linear levers were used, to reduce the amount of force the pedal needs to be pushed, make the lever longer and increase the pedal travel.

the nonlinear response of the ERK has the long lever, easier to push when the clutch is fully depressed. HOWEVER, the initial couple inches of the clutch are actually with a shorter lever and thus harder to press. But at this initial depression, the only force that needs to be overcomed is taking out the clearance for the ToB and depressing the clutch arms a little.



the green straight line marked with the 5:1 slope is the pedal to MC withOUT the effort reduction.

the red curved line marked with the 7:1 slope is WITH the effort reduction. the 7:1 slope line is between the pedal travel of 3" to 8". this was to show that at the pedal hold down, the pedal force is reduced 5/7 (~70%). BUT the pedal does need to travel more to move the MC (and slave). to prevent the pedal travel from getting way excessive, the effort reduction linkage causes the initial depressing of the clutch to stroke the MC faster for the first couple inches. This does mean it will take more pedal force than original for these few inches, However, this is the ToB free travel and just compressing the fingers so not much force is needed.

does this make sense

Side story, It was just last year when another discussion of this linkage got me interested in exactly how it works and how much improvement it makes. while I hadn't model 4 bar linkage since my school days, I think I got my equations fairly close. Now the bad part...during your discussion the fact the one piece could be put in backwards, I went back and tried to write the equations to see how much differance it makes...I was dumbfounded! I can't understand a thing I did a year ago

Thank you! The above input is appreciated.

So, if the ERK in fact does not reduce the total effort but only moves it from the initial part to the end part of pressing down the clutch, then I accept that the MC and therefore the slave moves the same amount. But I also read about one bracket maybe being reversed and that it needs adjustment to work right. Maybe Peter's is out of adjustment.

Personally I would prefer the least effort was required at the point of engagement, because that's where you sometimes have to make a slow and measured engagement, while at the start and end of the travel, it's just full force.

quote:

Originally posted by No Quarter:
Thank you! The above input is appreciated.

So, if the ERK in fact does not reduce the total effort but only moves it from the initial part to the end part of pressing down the clutch, then I accept that the MC and therefore the slave moves the same amount. But I also read about one bracket maybe being reversed and that it needs adjustment to work right. Maybe Peter's is out of adjustment.

Personally I would prefer the least effort was required at the point of engagement, because that's where you sometimes have to make a slow and measured engagement, while at the start and end of the travel, it's just full force.

When I made that model a year ago, I was a little "broad" with my exactness. at that time I just wanted to know the basics of how it worked and a general ideal how it works.

from an academic objective, once I saw the design was a "quick take up" stroke followed by a ~70% reduced effort stroke,

1) I randomly chose a starting point for the initial setting of that b/c angle, where I compared the expected pedal travel of the non versus the ERK. It did show there was a need for a small increase in pedal stroke (no way near the amount if the total stroke was 70% reduced)

2) as you imply, it would be vary easy to adjust the linkage so that the "quick take up" is ommitted and only a 70% LONG pedal travel would be need. I would expect this would put the "pedal on the carpet" before the MC piston bottomed out at full stroke

for that first modeling, I did a lot of the simplification assumptions in my head as I wrote the excel to provide the graphs. when the comments about being able to reverse that toggle, I wanted to perform a comparison calculations. However that is when I noticed I am no longer able to reconize the needed math. I have not given up on making this comparison as I am now trying to see if I can use "canned equations" and a Math evaluation software to solve for me. this also causes me to question the exactness of my first solutions, so at this time I will state those results should not be considered the absolute, but just the general response

3) as for where in the clutch's operation the different efforts zones are located, that initial "quick take up" which actually increases the effort, the pedal effort will be the force required for that clutch operation zone. that initial clutch force need to remove the ToB not touching clearance would be very small, so the fact the ERK makes it harder makes no noticable differance to your leg.

4) The clutch operation zone where finding the point of first "grab" will be in the reduced effort zone, thus requiring more foot travel to provide a better control during a normal take off.

an observation I have made during the years of working with levers, links and hydrualics; the general population falls to the perseption that making a setting to a link is most importaint in getting the system back in operation, ie the instructions of set the link to 3.4". where my approach is that the provided length is just where I can put the device back together and then the length MUST be trimmed to match the others

That modification was probably done for Ford by probably one of their contractors such as Kar Kraft during the period when Ford was actually building the cars and not Detomaso.

It was done using the original production clutch.

If you could control those conditions now, i.e., use the original production car without the kit and with, the simplest thing to do would just be to measure the pressure on the clutch pedal with the pressure gauge that Ford recommended to Ford dealers for servicing the brakes of regular production cars of the '70s.

Many had customer complaints that pedal travel was to the floor and service mechanics being notorious for not liking text book instructions would use their left foot for measuring acceptable travel of the pedal.

If you could put your left foot under the pedal and the brakes were fully applied AND the car stopped, that was a go.


The only way you can finish this debate is to accurately scientifically do the test as I just suggested.

It seems totally illogical to me that Ford would go through the trouble of installing the effort reduction kit at their expense, if it didn't solve the criteria they had put forward?

Maybe that criteria is just being misinterpreted here?

This is really a coffee house debate at this point but frankly in my view there is no one here that has the credentials to question the solution?

Furthermore anyone here suggesting that it doesn't work and it is the reason for the inability to adjust the Pantera clutch, and take it out of the car is the solution, is just plane irresponsible.

One thing that has to be considered here that was not even mentioned is that the entire assembly height of the clutch package has to be compared to the original.

It doesn't matter if someone sold you the "supposed exact replacement" to the original.

There are components that likely just don't match up. For instance the length of the clutch cover fingers, a change away from the original flywheel OR the differences in the assembled height with the clutch unloaded.

The Pantera clutch is a "go, no go device".

You put the mechanicals at maximum travel, adjust the clearance between the disc and the plate to the minimum (.035 to .038") and that's it dudes and dudettes.

That's the way it was done then. That's the way you do it now.


If the clutch doesn't lock up fully when released then, at that point you need to look at only two other components. The slave and the master.

You can effect the travel of those two by changing their bores. You want the stock bores for the clutch to work like it was new.


Like it or not, the original clutch worked. This attitude that if the Italians did it and because of that the engineering is incompetent is just something that overall on this car has to disappear.

It is just not true.


It seems a more practical endeavor to go hunt for leprecons, mermaids and unicorns? That is just as relevant?
Maybe just stick to driving a hemi Checker cab with an automatic? I don't know?

Now if you don't mind, I have to go attack someone over there. I don't like her purse and I'm going to hit her with mine just to show her what a purse really should be? I hope I don't kill her?

quote:

Originally posted by PanteraDoug:
1)... the simplest thing to do would just be to measure the pressure on the clutch pedal with the pressure gauge that Ford recommended to Ford dealers for servicing the brakes of regular production cars of the '70s.

2)... If you could put your left foot under the pedal and the brakes were fully applied AND the car stopped, that was a go.

for item 1)...would that be put something like a small "bathroom scale" on the pedal and measure how many pounds is needed to hold down the clutch pedal?
a gauge measuring the fluid pressure at full depressed clutch would be the same whether ERK or not is used

for item 2)...I don't see what is going on there. is that put your left foot under the clutch pedal to besure it doesn't go to the carpet, then use your right to depress the clutch (mashing your left toes) and verify the clutch is released by the car not moving with e brake applied

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Originally posted by JFB #05177:

quote:

Originally posted by PanteraDoug:
1)... the simplest thing to do would just be to measure the pressure on the clutch pedal with the pressure gauge that Ford recommended to Ford dealers for servicing the brakes of regular production cars of the '70s.

2)... If you could put your left foot under the pedal and the brakes were fully applied AND the car stopped, that was a go.

for item 1)...would that be put something like a small "bathroom scale" on the pedal and measure how many pounds is needed to hold down the clutch pedal? a gauge measuring the fluid pressure at full depressed clutch would be the same whether ERK or not is used

for item 2)...I don't see what is going on there. is that put your left foot under the clutch pedal to besure it doesn't go to the carpet, then use your right to depress the clutch (mashing your left toes) and verify the clutch is released by the car not moving with e brake applied

I was referring to the method of setting the brake pedal on the Ford '70s cars. Also the '60s and '80's Ford cars as well.

I don't know the reason other than Ford left the length of those rods up to Bendix, but that is out of character with the engineering staff.

Maybe engineering wanted the "at rest" height of the pedal at one specific height and the resulting geometry wound up putting the pedal almost on the floor? Don't know?

That is before the thick carpet mats became very popular though. Just a thin rubber mat is all that would fit safely.


Considering the possible changes to the Pantera over 40 years that clearance needs to be verified.

My pedal box is moved forward 1-1/2". That moves the pedals at full travel closer to the floor pan.



The only way you can adjust the height of the clutch pedal on the Pantera is to play with the length of the plunger rod.

Longer would raise it. Shorter lower it.

Small changes on those rods and/or not having the original one will definitely effect pedal heights.

In the past on other vehicles I have made my own out of 5/16" or 3/8" bolts to get the BRAKE pedal where I wanted it to be.

I give up

quote:

Originally posted by No Quarter:
I give up

Who will I argue with? That's not fair!

sort of surprising to me there isn't a prior anylitical evaluation.

I'm currently installing the Precision Pro-Formance effort reduction kit on my 72. I get exactly 1 1/2 inches of movement at full pedal travel. I'm using the CNC. master. It also has 1 1/2 inch stroke. The only way to get full stroke is to add a 1 inch spacer behind the master. I'm having that made now. There simply isn't enough space between there to get the full stroke. My car has the 3 finger clutch sold by PI. It works well but is stiff. After I add the spacer the hard line to the rear will be too short. What's the best way to lengthen it ?

Thanks, Mike 3482

quote:

Originally posted by PanteraDoug:

quote:

Originally posted by No Quarter:
I give up

Who will I argue with? That's not fair!

Hello Doug,

I began the thread about the bloody awful Clutch because I couldn't get it to work.

I won't repeat all that I did to try and fix it,
or you will all become like me and enrol in the nearest Asylum.

The thing that really hurts, is the fact that my old well worn clutch and its Effort reduction system ( that I didn't know was fitted) worked perfectly.


I disconnected the er system got a long throw slave but I know I don't have the answer.

I am going to write to Dennis and ask for advice but your comments are on the money.

We could also start an argument about Politicians, but I fear ours are just as bad as yours.

If you do find the cause of the problem, I would like to be the first to know.

quote:

Originally posted by Peter Fenlon:

quote:

Originally posted by PanteraDoug:

quote:

Originally posted by No Quarter:
I give up

Who will I argue with? That's not fair!

Hello Doug,

I began the thread about the bloody awful Clutch because I couldn't get it to work.

I won't repeat all that I did to try and fix it,
or you will all become like me and enrol in the nearest Asylum.

The thing that really hurts, is the fact that my old well worn clutch and its Effort reduction system ( that I didn't know was fitted) worked perfectly.


I disconnected the er system got a long throw slave but I know I don't have the answer.

I am going to write to Dennis and ask for advice but your comments are on the money.

We could also start an argument about Politicians, but I fear ours are just as bad as yours.

If you do find the cause of the problem, I would like to be the first to know.

The cause of the problems with politicians? No. My doctor will not permit me to discuss that. She fears for my life from 1) stress 2) bodily harm for speaking truth to power.

Go the money and call Denis on this.



Theoretically you have done everything right. Let him go over it with you step by step.

In my mind, one of the parts has to be wrong. It must have been mismarked or substituted for.

Ask Dennis if he personally check every part that he sent you or if he just had his "shipping department" re-box it?

Also ask him if the throw-out bearing is a full contact (always in contact) part. Those these days are also referred to as a ceramic surfaced TO bearing.

Careful there though. Your fingers on the pressure plate need to be specially hardened in order to permit that to prevent rapid wear on them.


If you have an aluminum flywheel, that could be the source of the problem right there. The brass ring that is inserted maybe could not be completely seated in the pocket in the flywheel itself.


If the bolts that hold the pressure plate together are not tight enough, the fingers will be too high. That's a long shot as a possibility but possible.

Other than that, send me a 'plane ticket. Pick me up at the airport.

I don't eat much, but none of this kidney pie stuff. Maybe fish and chips? They both need to be very crispy. I don't suppose you know what Buffalo wings are right? Either a pretty wench and a little beer, or a not so pretty one and a lot of beer.

Hey! We drink cold beer here. Bud Light, Amstel Light, some kind of light beer. "Tastes great...less filling".

I'll watch your "football". Manchester City, Arsenal, Manchester United or Chelsea will do.

Oh, BOAC is good. Not coach.