Thinking about recent events, and how the top half of the clutch pedal got flimsy, and wondering how things work.

Is the actual point of disengagement for the clutch by the slave cylinder from the master cylinder from the pedal (phew!)... is that at the bottom of the clutch pedal travel? And is all the pressure at the top half of the pedal travel actually the hydraulics managing the feedback for that transition?

 

That's one confusing question.

My understanding is with the pedal fully depressed, slave moves sufficient distance to fully disengage the pressure plate from the friction plate. For a certain pedal movement before that, pressure plate/friction plate clamping force is insufficient for full engagement (slipping). With the pedal near/at the top (off the floor), there is minimal pressure against the pressure plate and clutch is fully engaged.

I suppose the actual answer to your question is that it's a function of the master cylinder. I think initially you're working against the spring in the master as you push the pedal down. To ensure full engagement, there should also be a small amount of play when the pedal is at the top. As for full disengagement, it would seem there is excess movement in the stock mc beyond the clutch being disengaged. This is what allows the rjm to vary the friction window while still being able to fully disengage.

It would be interesting to graph the master movement against the slave/clutch full engagement/transition/full disengagement.

 

Fair enough. That was a confusing answer, LOL.

 

 

Rochester,
Personally I wouldn't recommend it. I would simply loosen the nuts to move it upwards so it's completely not making contact, reset the AFP the clutch rod adjustments to dial the pedal feel in to where you like it best and then adjust the switch down as normal. As unless you alter the AFP or clutch rod again after the fact it will maintain the correct setup indefinitely. The AFP having moved on you setting off the current chain of events resulted from the AFP lock bolt having been left loose at some point in the past allowing the adjustment to back itself out. However, removing it completely puts all the stress of the pedal stopping at the top (stopping the upward momentum of the pedal on quick shifts) on the rear retaining clip of the master cylinder which could eventually bump or jar itself free of the groove it sits in and allow the master cylinder to come apart causing complete loss of fluid and clutch pressure. When the switch is adjusted correctly with the button just fully depressed and the rubber bumper just at the metal body of the switch that upward bump momentum is absorbed by the stop bumper against the switch & switch mount, thereby limiting any stress on the rear of the master cylinder.
As well I don't know how exactly the car would react getting mixed signals from the safety switches by taking the upper switch out of operation and if that could have any negative impact on other systems such as ABS, stability or traction control in case the ECU somehow looks at the switch status when deciding how it will react to certain conditions.

So bottom line I wouldn't recommend it.
Best Regards,
Ryan@RJM

 

 

@Rochester, I'm curious why you would want to remove this switch? Once properly adjusted and locked down it shouldn't move.

 

 

I finally installed my RJM clutch pedal and now ion the adjustment part. I have to say this is a bit confusing coming from someone that just started modding cars and doing most work myself.
My question is. after installment i noticed i still had some free play but looks like its coming from the MC rod. Adjusting the cruise control switch is going to eliminate that freeplay?

 

Yes, if you have any free play left in the linkage from the MC and clevis then you can remove that slight bit by adjusting the upper cruise switch. If however you're talking about the 1/2" or so of initial soft travel that is normal and can not be adjusted out. It was always there (just like the soft take up on your brakes) but the overly stiff factory pedal spring masked this initial soft portion of the travel. The RJM doesn't do that and you now feel the system exactly as it is with no artificial manipulation of the pedal feel by the factory assist/return mechanism. Hope that helps. If you need further clarification or tips on setup please don't hesitate to shoot me an email.
Best RegardsBestRyan@RJM
Ryan @ RJM

 

man! i miss forums.. and whew ive been using this pedal since 2015 wow... anyhoo finally changed out the factory clutch setup and it seems like i need to re tune the pedal.. have to look back and see what i did in the 1st place lol