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SM465 mech. linkage vs. hydro

Hogback Fabrication

Hogback Fabrication

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I hear all kinds of talk about how much easier the pedal effort is with hydro setups, someone prove it.

Hydraulics are simply a way to use fluid as a mechanical advantage, just like levers.

Its not like the hydro-clutch pedals have twice as much travel, AFAIK the mechanical and hydro clutch use the same lever arm distance.

I've driven mechanical and hydro clutch K5's and I don't feel there is any difference in pedal feel. IMO, the difference is mostly in people's heads.

I'm well aware of the advantages/disadvantages of each setup ;)

So, assuming you have frame/body flex issues under control (which I do and did when mine was full bodied) convince me why a hydro clutch is the way to go.

I've replaced many a clutch master cylinder and slave cylinder in my day, why does everyone think the hydro stuff is the hot setup?
 
I had the mech. setup in my fullsize. It was pretty stiff but then again it was a 3 finger pressure plate. I have a hydro setup in my project now and seems to be easier. It has a diaphram pressure plate. IMO i think the only difference is in the pressure plates.
 
bronc3buster842001 said:
I had the mech. setup in my fullsize. It was pretty stiff but then again it was a 3 finger pressure plate. I have a hydro setup in my project now and seems to be easier. It has a diaphram pressure plate. IMO i think the only difference is in the pressure plates.
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I agree that the pressure plate make a difference, I've run both and totally agree that pedal effort is different between the two.
 
The problem with mech is that for most of us the parts are old, sloppy, etc. Each pivot point is a 'loss' of applied force from the pedal, and with only so much pedal travel to play with the mechanical advantage isn't that great.

Hydro requires no periodic adjustmant, no exhaust clearance problems, and no chance of having the whole affair fall apart when the truck gets twisty.

As for pedal feel, mech is fine if you have a stockish diaphram clutch...but with any 3 finger clutch it's a real bear on the left leg. Having swapped to the hydro after running the mechanical for the 11 years previous I do feel the pedal is lighter with the hydro. Unfortunately I don't have a direct comparison (same disc with mech vs hydro) When I swapped to the hydro clutch I installed a Hays puller clutch at the same time, from a reman stock diaphram clutch. The Hays is a much heavier clutch with a larger PP, but pedal feel is still lighter. Not a Honda clutch though...

In all the time I had my truck I repaired, adjusted etc the mech linkage a good half dozen times. A couple times were on the trail where it fell apart. I got it set up so it wouldn't fall apart, but then had other problems. Notably when the pivot ball sheared while I was in downtown traffic.

Rene
 
In all the time I had my truck I repaired, adjusted etc the mech linkage a good half dozen times. A couple times were on the trail where it fell apart. I got it set up so it wouldn't fall apart, but then had other problems. Notably when the pivot ball sheared while I was in downtown traffic.


I bet that was fun.
 
tRustyK5 said:
The problem with mech is that for most of us the parts are old, sloppy, etc. Each pivot point is a 'loss' of applied force from the pedal, and with only so much pedal travel to play with the mechanical advantage isn't that great.
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There is certainly a bit more friction involved with mechanical linkage, probably pretty negligible IMO.

The hydro setup has to get its mechanical advantage from the same pedal travel (I believe) so that's not an difference between the two AFAIK.

tRustyK5 said:
Hydro requires no periodic adjustmant, no exhaust clearance problems, and no chance of having the whole affair fall apart when the truck gets twisty.
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Hydro lines can leak, slave cylinders and clutch master cylinders can fail and leave you with no clutch.

Again, each setup has its advantages and disadvantages.




tRustyK5 said:
but then had other problems. Notably when the pivot ball sheared while I was in downtown traffic.
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Yeesh, that would be no good. Haven't heard of that one but certainly a downfall to the mechanical stuff.



I'm not targeting anyone or saying that swapping to hydro clutch stuff is a bad idea, I'm kinda playing devil's advocate here.

In the name of tech and more information, explain why the hydro stuff is worth it (this is not aimed at any one person).

I am seriously not convinced to swap away from my mechanical setup and I (personally) don't understand why so many people spend so much time and effort swapping to the hydro stuff.
 
The only reason i went with hydro is because of space. Mech is cheaper to convert to it ya have the run for the linkages.On my S10 blazer there just wasnt any room for linkages so i had to go hydro.
 
I will say pedal feel, and perceived control is much better with the hydro clutch.

That being said, I swapped to hydro because it was a ton less work than trying to make the mechanical stuff work with my NV4500.

The pivot ball I had fixed in 15 minutes. I found a 1/2" bolt that I was able to make work. This was only days after I got rear ended really hard which I believe had something to do with the pivot failing like that. I had the clutch depreseed when I got hit...('77 F-100 @ 55 mph :eek1: )

Either set-up can work well...but both require the parts to be in good shape.

As for the mechanical advantage, I wish I still had my mech set-up here so I could do a side by each comparison. The whole thing is quite different up under the dash with the hydro pushing a rod forward through the firewall compared to the mech pushing a rod down through the floor/firewall interface area. I could see how the amount of mech advantage could actually be quite different depending on where all the pivots are.

One advantage with hydro is if you're building a buggy, you can hang those pedals how and where you want as long as the slave hose reaches. A ton eaier to custom set up than mech linakge would be. :D

Rene
 
My 77 K20 was an automatic, swaped in a stick with mechanical linkage. Hated it. It would always fall appart at the worst time and need adjusting. Swaped the same setup into my 87 K5. Love it. When I put the stuff into the K5 I rebuilt the linkage, now it stays in adjustment. Hasn't fellen appart yet (knock on wood). I think the main reason it was failing in the K20 was the cab would shift around.

Now that I have a good working mechanical setup...I wouldn't trade it for anything.

I think I'm also better able to feel the point of engagment better with the mechanical. My 83 Camaro has a mechanical system and my 88 Camaro has a hydro. The 88's pedal is lighter, but it seems like the clutch is harder to slip. It's either on or off.
 
Mech linkage sucked for me. Before I did my cage I had a ton of frame flex. My linkage would either fall apart or it would engage my clutch while flexing out. One time it did it so bad it pushed my fork off the throwout bearing, ask me how fun that is. I went hydro and couldnt be happier.
 
protechk5 said:
Mech linkage sucked for me. Before I did my cage I had a ton of frame flex. My linkage would either fall apart or it would engage my clutch while flexing out. One time it did it so bad it pushed my fork off the throwout bearing, ask me how fun that is. I went hydro and couldnt be happier.
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i have problems like this but not that bad...when my truck gets twisted up i almost have a diffrent relese point everytime...i actually watch the clutch pedal move while driving off road...now i have a well built cage so i dont know what thats gonna do to it...i have hydro in my dd and other than it being easier (its a dodge dakota) that all the experiance i have
 
38377k5 said:
I am seriously not convinced to swap away from my mechanical setup and I (personally) don't understand why so many people spend so much time and effort swapping to the hydro stuff.
Click to expand...

you can do it for about 200.00, stock non hydro bell and a couple hours..
 
If you're asking whethere there's any mechanical advantage gained by the hydro, the answer is no. The hydraulic fluid just transfers the power from the master to the slave. The mechanical advantage is determined by the clutch pedal pushrod and the clutch fork pivot points....here's a site to back up my opinion: http://www.novak-adapt.com/knowledge/clutches_etc.htm

I didn't have any linkage setup when I swapped to manual so hydro just seemed like the most straightforward to setup since I didn't want to mess with adjusting it. If I had a mechanical setup that was working ok, I wouldn't bother swapping it out.
 
Hydraulic is easier than mechanical for sure.

I guess you could compare it with power steering versus manual steering the best. Both systems use the same steering components but one system uses a manual steering box with only operator assistance (yourself) while the other system uses a hydraulic steering box with operator assistance AND hydraulic assistance. Obviously the system that uses two different types of assistance will be easier. The same thought can be said manual brakes versus power brakes.

You can always argue that the leverage of a mechanical system could be greater than the hydraulic therefor being the same effort but no amount of mechanical leverage will ever be greater than hydraulic pressure.

I know someone is going to argue this point and i'd love to read about it. :D
 
Well, the hydraulic's involved are not boosted by any artificial method like brakes or steering so the comparison isn't that relevant. The clutch hydraulics are a pure 'slave' system only tranferring the input leverage using fluid rather than mechanical linkage.

The question is which system has more mechanical leverage in the pedal system.

If both systems have 10:1 leverage, then it's really moot all things being equal, such as sytem condition and clutch type. This is assuming you have body/frame flex at an acceptable level.

Rene
 
I've been enjoying reading this thread so now I'm gonna jump in. I do not know what the bore and stroke diameters of the master and slave are on the hydro clutch but you can certainly create leverage without boosting a hydraulic system. I hand pumped hydrailc jack comes to mind. I guess we need to find out if the master and slave combo in the hydro clutch setup really do have any more mechanical advantage over the amaount of leverage created through the mechanical clutch system
 
If there was any real difference in the bores the effective stroke at the slave would be much reduced. Both the clutch master and the clutch slave have a nearly identical stroke, leaving all the mech advantage in the pedal assembly itself.

That being said I haven't measured the exact stroke of either...but having a complete set-up off the truck here i will.

Rene
 
tRustyK5 said:
If there was any real difference in the bores the effective stroke at the slave would be much reduced. Both the clutch master and the clutch slave have a nearly identical stroke, leaving all the mech advantage in the pedal assembly itself.

That being said I haven't measured the exact stroke of either...but having a complete set-up off the truck here i will.

Rene
Click to expand...

That is the answer I was expecting and part of what has kept me from jumping in on this but now i actually want to know if there is any advantage produced by the hydraulic assembly
 
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