Question for those who have done a hydraulic clutch conversion.

After doing a hydraulic clutch conversion did your pedal effort change much? My left knee is starting to hurt due to age, work, ice hockey and my CJ is not helping. I have thought about a TH350 conversion however I would like to keep my T18. Any information would be great.

Thanks...
Tom

 

Oh man! I was just thinking about posting this same thing. I have a partially torn ACL and it aint gettin any better. I want to keep my t18 in my 73 as well.

I am subbing this thread like you don't believe!

 

We are both in the same boat. Lets hope we get some answers. One thing I am thinking of is a Centerforce clutch. I installed one into a 69 Bronco I restored for a guy and the clutch felt great. I had to post a picture, it was a 3 year frame off project that I am proud of.

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Questions for both of you: 1) What size is the bore on the dash or floor mounted Master cylinder for the clutch slave? 2) What size is the bore of the slave cylinder? 3) What type is the Slave Cylinder? some can be push while others are pull 4) How much travel is needed to fully release the clutch? This would be the distance that the slave push rod is traveling? 5) What is your Pedal Ratio at the Clutch Master cylinder? see below?

Simple Mechanical ratio at the clutch pedal needs to be around 6-7:1.........the greater the ratio is , the lesser the force becomes to move the pedal ......but as the ratio increases the pedal has to travel farther to do the same work!. On the bore sizes a similar hydraulic ratio also comes into play...........Smaller bore at the master equals more pressure ( less pedal pressure ) but less fluid volume.......larger bore equals more volume but requires more pedal pressure.............all of these need to work together to get the end result you require.........Pedal Pressure, enough fluid volume to move the slave far enough to push the clutch fork to release the clutch pedal.............easy when you understand how to get there.

 

I have not done a conversion yet. I was doing research as to what would be the best way to go. Are you running a hydro set up? If so what specs and parts are you running? I want to do it right the first time if I do it at all. That is why I am throwing the question out there.

 

Done plenty of them..........But there all different.....based on components, pressure plate force and how your pedals are mounted and the room you have to swing the pedal...........you say a CJ which doesn't tell anyone anything.

 

Copy that. Ok I will rephrase the question with more information.

I have a 1967 Jeep CJ5 with a odd fire V6, T18 4 speed, Dana 18 transfer case with Warn overdrive.
The Jeep still has the stock clutch linkage and the pedals are floor mounted.
I am not sure what clutch the previous owner has installed.
My problem is after driving the Jeep my left knee hurts.
What I would like to hear from people like yourself that have experience with hydraulic clutch conversions is what was the pedal effort before and after the conversion.
I understand there are different ways to do the conversion with different components, so I would like to hear the successful stories and if someone has a not so successful story that can be good information for me also.
I am trying to do this conversion one time, so if I can learn from experienced people like yourself that can only help me and maybe others thinking about the same conversion.
I do have a set of XJ and intermediate CJ swing pedals so if a swing conversion at the same time makes sense I can do that also. Or there is the Wilwood swing pedal set up.
As far as slave cylinders what have people had good luck with. Novak or some other kind of set up?
What about a clutch pressure plates is there a soft one that people know of and like? I do have experience with a Centerforce I installed in a 69 Bronco and it did feel great.
If the whole project seems like a pain or I may not get the results I need it the Jeep may get a TH350 swap.

Thank you all in advance for the information and input.

Tom

 

Tom...............there really is no one answer fits all..........First off trying to mount a clutch master cylinder on a floor mounted pedal assembly is possible and has been done , but it is a big hassle.

Do you think this was a factory installed V6 ? Who modified the Bell Housing and installed the T-18? And what clutch components inside the bell housing were used during the install?..........Point is if someone cobbled this stuff together and did not pay attention your problems could be right there!

When you say you have mechanical linkage I assume there is no cable in the system is that correct?

What I would First do is start looking , measuring & going through all your mechanical clutch linkage using the ratio values that were given earlier.........Notwithstanding the clutch fork length from the ball pivot out to the push-rod and also the style of throw-out bearing face whether it be flat or curved and how it align's with the pressure plate along with proper lubrication at all these points including the candlestick where the bearing rides on..........any or all of these area's will contribute to a stiff pedal..........but more than likely the ratio's would be more suspect.

As mentioned you need about a 6-7:1 ratio for an average sized person to easily apply about a 70-100 lbs of force to the clutch pedal.........once the linkage gets to the clutch fork at the bell housing the ratio there changes to 2:1 as it moves to the throw-out bearing on most applications..........if the fork used is less than 2:1 then the force required to move it becomes much greater at the pedal. One other thing that goes mostly un-noticed is the need to properly time the linkage in a sort of "Sweet spot" within the arc it travels in......meaning the start of the application of the force has to be in the correct location as compared to the point of the fulcrum...............Lots of possibility's to where the problem may be , but the good news is it is just purely mechanical and can be fixed or at least made better.

 

Some info that might help.

I didn't do a swap but I did a install when I built it. On my 57 CJ5(225/Ford T18/20)I used a complete hyd system off a 81 4cyl CJ, hanging pedals and all. While not a direct bolt on it works good. Some issues you will encounter with any hanging pedal swap is that the floor is shallower than most of the common swap donors. This is overcome most of the time by heating/bending the pedal arm to get the full swing resulting in having to lift your foot higher. Also with a push style slave you need to add some length(weld on) to the throwout arm as to it was a cable pull type.

I would suggest looking into a underfloor master with a firewall mounted reservoir to keep the pivot below the floor. I think this will be easier on your knee since you push down rather than out(more hip less knee).
A pull style slave will be a little trickier to mount but you won't have to modify the clutch arm.

 

Never installed one but seen plenty of guys using them or ones they built with no issues........Not sure what the size of the pulley is and if it would create a better ratio.......I would think as long as the chain and pulley remained greased up it should be as easy as any linkage and maybe even a little smoother.

 

This. I used XJ hanging pedals, brake booster, and clutch master cylinder. I used the Novak hydraulic clutch conversion kit, along with their adjustable TO bearing as well as an adjustable fork pivot. Like said above, I did have to bend and grind a bit off of the back of the clutch pedal in order to have enough throw. Its all dialed in pretty well and I highly recommend the conversion parts that I used. This was all done as part of my SM465 swap.

 

Yes it is a factory V6. I am thinking the T18 conversion was done a long time ago and you are right, who knows what parts went into it.

It has linkage from the pedal to the bell crank and a cable from the bell crank to the clutch arm.

I will check out the basics and make sure everything is dialed in.

I did do a adjustment to the bell crank and the clutch did feel a little bit better.

Thanks for the information.
Tom

 

This is the direction I was thinking of.

Thanks...
Tom