Need hydraulic clutch conversion advise/guidance

[Lumpy Grits]

What was your first clue-----
LG

 

[Hedgehog]

I generally like simple answers for parts that otherwise work well. Rather than replace the bell crank, why not simply move the whole thing closer to the bell housing. About 3/4" would do, I think mine will adjust that much. If yours is like mine, simply remove the plate the bell crank ball end sits on, drill a new hole that tightens everything up and bolt her down.

I'm working up a replacement for the bell housing mount and the nylon bushing. It consists of a nut (or a threaded section) welded into both ends of the crank. The bearing would be a heim joints supporting both ends, attached to a plate similar to the way jeep did it, but not supported by the bell housing. The drive train would still twist some, probably not enough to affect a properly adjusted clutch.

 

[tarry99]

As I do further research, I have encountered another potential snag. In looking at various kits, I find that PartsMike's website states that hydraulic setups do not work well with performance heavy duty clutches and pressure plates.

HYDCL00SS HYDRAULIC CLUTCH KIT CJ AND UNIVERSAL

They say to use only stock parts. This seems counter-intuitive, as many race cars use a hydraulic clutch set-up. Any opinions about this?

You should be fine...........if in question you can add a little more ratio or mechanical advantage to the pedal or play with the bore sizes in the cylinders although by doing so it does increase the stroke ever so slightly......

As far as your pedal ratio is concerned.......you need to crawl under there and measure what you have..........and then see if you have another hole or place to drill another hole..........best just to use what you have rather than buy another.

And if you have the linkage adapter between the firewall and booster you then should have enough room to squeeze the clutch master along side it.
As you probably already know due to moving the Master cylinder forward new brake lines may be needed.

 

[Oldguyinajeep]

Here's an update. Following Lumpy's advice, I've had the frame thoroughly inspected. No issues. So....

I've decided to proceed with the hydro clutch mod. One last question: My local jeep guy that sells used parts has a pedal out of a CJ originally equipped with a hydro. Everything I've seen regarding this mod says to use a YJ pedal. Is there any problem with using the CJ pedal? Is there something superior about the YJ pedal, or (as I suspect) is it just that there are more of them available? I would need to go to the salvage yard for one of those, whereas the CJ pedal is already pulled (and cheap).

Also, regarding the slave cylinder: a problem that is sometimes mentioned with the OEM type is the lack of adjustability. The Novak brand is adjustable, and gets good reviews. But, it's $180, vs $25 for OEM. Think I'll try the OEM first. If it doesn't have enough throw, I may try cutting the pushrod, threading it, using a coupling nut and part of the rod remnant to fashion an adjustable rod. Have any of you done this? If so, tips would be appreciated.

Thanks

 

[tarry99]

Here's an update. Following Lumpy's advice, I've had the frame thoroughly inspected. No issues. So....

I've decided to proceed with the hydro clutch mod. One last question: My local jeep guy that sells used parts has a pedal out of a CJ originally equipped with a hydro. Everything I've seen regarding this mod says to use a YJ pedal. Is there any problem with using the CJ pedal? Is there something superior about the YJ pedal, or (as I suspect) is it just that there are more of them available? I would need to go to the salvage yard for one of those, whereas the CJ pedal is already pulled (and cheap).

Also, regarding the slave cylinder: a problem that is sometimes mentioned with the OEM type is the lack of adjustability. The Novak brand is adjustable, and gets good reviews. But, it's $180, vs $25 for OEM. Think I'll try the OEM first. If it doesn't have enough throw, I may try cutting the pushrod, threading it, using a coupling nut and part of the rod remnant to fashion an adjustable rod. Have any of you done this? If so, tips would be appreciated.

Thanks

First off since I have no Idea what components you are using I can only speak in generalities ........Most of what I do is non-factory modifications. You may very well be able to use factory parts that are mixed and matched to get you where you need to go.............as not all modifications will be the same on all vehicles............but what does remain constant , be it factory or otherwise is the need to apply known proper ratios and hydraulic bore sizes to the build.

YJ , CJ , or anything other pedals that will get you the ratio & Pedal travel will work...........nothing magic about the YJ pedal assembly short of the availability for this type of modification. In Early CJ's this assembly is a good choice but may require the shortening of the pedals to get adequate travel between the floor and firewall which in a early CJ is compromised based on the shape of the floor & firewall.

If you already have a clutch pedal in place there is no reason it cannot be re-used by correcting the ratio If needed, this may also include being able to line up the push rod from it to the clutch master which may require an offset push-rod or bracket , but then again maybe not.

Go back and read what I posted in #2.

No Slave cylinder including Novak's has any built in adjust-ability.........the mount and position of where that mount and slave is placed or attached to the bell housing is the starting point of the travel and adjust-ability. That is why I mentioned the mount should remain fluid or adjustable until you know exactly where it needs to be placed. That only comes from trial & error especially when using mis-matched parts.

Novak has some good articles on line regarding clutch linkage and Ratios. Some of that information was knowledge I shared with Novak's owner years ago especially in the ratio category

You cannot increase travel in the system as you have suggested by adding a longer or shorter push-rod...........that only moves where the start and finish of the travel begins. .............

It's the travel built-in to the Novak longer bore & piston that makes it far better than most.........The Novak slave can travel about 2" while other OEMs slaves only travel a portion of that..........Now again that is not to say that a standard slave will not work when put together with all the stock components in a stock environment.......the Novak just shines when your using non-stock as it give you a larger range to correct from.

I would look at your system and components and if they are basically factory stock components , engine , bell housing , Transmission & clutch , find the parts and bolt them on and you should be fine. As I mentioned previously the Iron Duke GM 4-cylinder available in your model year has perhaps all the hydraulic clutch components you need..........Sorry if you lived closer I could tell you exactly what you need.

 

[Lumpy Grits]

The Novak is a very good setup if you're go'n 'hydro'.
This would not be the place to worry about a few pennies in savings.
Good luck,
LG

 

[Hedgehog]

go hydro, but do remember one thing. Mechanical connections can be fixed in the field, hydro's leak hydraulic oil on the ground.

 

[Oldguyinajeep]

Thanks for the responses, guys. Tarry99's fund of knowledge in this area is obviously expansive.

I will initially use stock MC and SC, in an effort to do what you mentioned, i.e., stay with known proper ratios and bore sizes. That was part of the reason I was asking about the TJ pedal, as it makes more sense to me that the CJ pedal would be an exact match. I'll look at the Novak site's resources, and see if I can learn how to measure pedal ratios. I've read others speak of the Novak "adjustability", so I'm glad to know there is no actual adjustment, other than positioning. People do speak of the additional travel as an advantage.

My wording was poor, in my previous post. I'm aware that the travel is Limited by the piston travel within the unit. What I was suggesting with an adjustable rod, is being able to move the starting and finishing points without repositioning the cylinder in a trial and error fashion, as you suggested. Can you think of any reason why that would'nt work.

 

[Oldguyinajeep]

Hedge, regarding you comment: don't think I haven't gone back and forth over that fact. I like simple and mechanical, too. But... I look at how many miles in how many vehicles over my 55 years of driving I've gone with only a couple of issues with hydraulic brakes (rubber hoses), and it seems pretty darn reliable to me. I sure hope I'm singing the same song about hydraulic clutches

 

[Oldguyinajeep]

oops. Make that 45 yrs

 

[Lumpy Grits]

When you find what works-Carry a spare MC & SC along with the brake fluid need'd. That will make a trail fix/repair easy.
LG

 

[tarry99]

That was part of the reason I was asking about the TJ pedal, as it makes more sense to me that the CJ pedal would be an exact match. I'll look at the Novak site's resources, and see if I can learn how to measure pedal ratios.

What I was suggesting with an adjustable rod, is being able to move the starting and finishing points without repositioning the cylinder in a trial and error fashion, as you suggested. Can you think of any reason why that would'nt work.

At this point you need to crawl under the dash and measure both the brake and clutch pedal anyway.........since your changing over to power on the brake side and adding a hydraulic clutch ..............just so ya know what you have to work with.

There is allot of force generated at the slave to the push rod......A long push rod has the tenancy to flex or bend off to one side if it is not exactly horizontal or directly in-line between the slave and clutch fork........you only want to do this once so keeping the push rod a standard length is better. If the equipment you have is all OEM and you can find the factory brackets in the wrecking yard then by all means grab them up.

Here is a diagram to help you on ratio.........divide one into the other.

 

[Hedgehog]

Not to belabor the point. You and I've been driving about the same number of years. In those years I've had two vehicles with hydraulic clutches and MGB-GT and a '80 CJ5 . Both failed, both destroyed the paint under them, both got new slave and master cylinders. I dropped the hydraulic clutch in my CJ and went to a mechanical linkage. I won't say any more on the subject, you've made up your mind and that's a good thing. Hydraulics can be a cure for many clutch problems.

 

[Oldguyinajeep]

T99, you are correct about the pedal length. My 86 is about an inch shorter than the older pedal from the hydro clutch. You mentioned in an earlier post about shortening the older pedal. I could do that, but that would change the ratio, then I'd have to relocate the MC pin to adjust, right? So, I might as well do as you suggested and use my existing pedal, and relocate the pin. I haven't calculated how much, but I'll have to move the MC pin upward a bit, due to the shorter pedal length to maintain the ratio. That will change the angle of the MC push rod if mounted in the factory location, right? If so, I can't use the knockout on the firewall, I'll have to move the MC up a little to keep the rod thrust level, correct?

Hedge, I really do appreciate your perspective. And I will follow Lump's advice and carry spares. They are small, and don't weigh much.

Thanks again guys.

 

[tarry99]

T99, So, I might as well do as you suggested and use my existing pedal, and relocate the pin. I haven't calculated how much, but I'll have to move the MC pin upward a bit, due to the shorter pedal length to maintain the ratio. That will change the angle of the MC push rod if mounted in the factory location, right? If so, I can't use the knockout on the firewall, I'll have to move the MC up a little to keep the rod thrust level, correct?

Oldguy,

I know your anxious to figure this but slow down a bit and measure what you have first..........Again , I don't know exactly what your working with there, But before you move the push-rod location on the pedal it may be just as easy to adjust the location on the firewall as to where the Clutch master goes as long as it corrects the ratio.

You have to take into account all of the Items that need to be done before you start drilling holes as sometimes the obvious hasn't been noticed yet......best to build it in your mind or a drawing first before you proceed.

If all your parts are original I'm still thinking that only slight changes may be necessary keeping in mind that the ratio for the mechanical clutch linkage your replacing as well as the Hydraulic slave are about the same at approx. 5 to 6:1.....