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View Full Version : american powertrain hydromaxclutch setup



mikes55
05-12-2015, 07:08 AM
has anyone installed a hyd clutch setup in their 55 chevy. I bought one but instructions are not that great and it looks like it is more universable than direct fit. the bracket for the clutch master cyl hits the steering rag joint and if you put the rod end on the opposite side of the lever under the dash then the cylinder is real clost to header. I would appreciate any feedback on how you did to correct this problem. thanks mike.

chevynut
05-12-2015, 07:13 AM
I would appreciate any feedback on how you did to correct this problem.

I built my own. ;)

Is there any way you can mount it so it just clears the rag joint? I'd rather do that than be close to the header. Maybe you need to get rid of the rod end and use he stock clevis to move it over a bit.

mikes55
05-12-2015, 07:22 AM
I thought of something like a clevis that would strattle the lever under the dash and it would move it over probably just enough cause swapping rod end to other side of lever moves it 3/4 inch over and its clost to header where it could damage ceals or boil brake fluild. I wonder if its worth the trouble or just keep manual linkage. I am wondering how much more it will be pressing the pedal from hyd to manual

chevynut
05-12-2015, 07:49 AM
IMO the advantage of a hydraulic clutch is that you don't have to worry about getting the rods lined up and clearing everything, and not as much linkage to wear and go out of adjustment. A hydraulic TO bearing makes it even simpler, but I'm leary of them since a lot of guys seem to have leaks using them. Once they leak you have to pull the tranny to fix it. I prefer a hydraulic slave and clutch fork, if there's room for it. I just think a hydraulic setup is simpler to execute.

If you can make the stock mechanical linkage work within the contstraints you have and perhaps improve it with rod ends, it should work fine. The pedal force should be no different from mechanical to hydraulic with the same pressure plate unless you have a lot of friction in the mechanical setup.

mikes55
05-12-2015, 09:12 AM
yes I think my complete new stock manual setup will work and I had bought it thinking it would be a simple set up but it doesn't look to be. do you know of anyone who sells the manual set up with rod ends? yea kind of worried about that bearing leakin too.

chevynut
05-12-2015, 09:27 AM
For some reason OEMs seem to be able to successfully use the hydraulic TO bearing with good results. I'm not sure what rate they leak in new cars. One of my customers installed THREE new GM TO bearings, and they all leaked, requiring him to pull the T56 3 times. If an external slave leaks, it's an easy job to replace it.

Earle Williams sells a manual clutch setup with rod ends but it's pricey. You could thread the rods and add the rod ends yourself.

http://www.williamsclassic.com/#!__products/other/vstc10=clutch-pedal

IMO if it was me I'd still go with the hydraulic setup if you can make it work without too much hassle. I just like the simplicity of the setup.

Rick_L
05-12-2015, 11:34 AM
I don't think he has a complete kit, but I've seen pieces that Earle Williams built that have rod ends. I suggest you call him.

As for your clutch master cylinder mounting, the mounting surface for the m/c probably needs to tilt away from the firewall at approximately 10. This moves the bottom of the m/c forward and up. It's what fixed my home grown setup clearance wise. Several of the aftermarket brackets have this feature, it works on other cars too.

Just guessing here since you didn't post a photo, which would help a lot.

mikes55
05-12-2015, 11:35 AM
meaning with a slave cylinder or with the hyd bearing? I would like to know if all of the work and the chance of it leaking is worth switching and if it will make the clutch pedal that much easier. did you ever hear of any one using the American powertrain hydromax system with good results. you seem to know a lot about the hyd vs the manual setup.

mikes55
05-12-2015, 11:41 AM
yes it does tilt but the problem im having is the bracket for the master cylinder hits the rag joint and if I put the rod end on the other side of the lever under the dash to move it over its too clost to the header. have you heard of anyone using this setup and how the set it up and does the hyd throw out bearing hold up?

markm
05-12-2015, 12:51 PM
Years ago on the other site I was complaining about the wore out welded junk I had for a clutch linkage and Rick and others suggested Earl Williams. Sent my junk off for his upgrades and have never regretted it.

chevynut
05-12-2015, 03:43 PM
meaning with a slave cylinder or with the hyd bearing?

I'm not sure what you're asking in that question. You might try the "reply with quote" to help clarify your question.


I would like to know if all of the work and the chance of it leaking is worth switching and if it will make the clutch pedal that much easier.

There isn't much you can do to make the pedal easier to push. If you change the leverage to lower the pedal force, you sacrifice travel. You need to push the clutch fingers in some given distance and it requires some force to do it. If you change that force by 2X with a lever, your travel has to change by 2x. That's what all the linkage does, and what the hydraulic setup does. A good functioning mechanical setup with the same travel will take the same force as a hydraulic setup. The only way to change that is to change the pressure plate. A diaphragm pressure plate takes less force than one with levers (don't remember what they're called).

Typically a hydraulic clutch works on a 1:1 piston ratio between the master and slave cylinder. That means when the pushrod on the MC is pushed 1" the slave moves 1". The position of the pushrod on the pedal determines how far the pedal travels to depress the MC that 1". The higher the pushrod is on the pedal, the easier it will be to push the pedal down, but the lower the travel. It's all a matter of leverage.

We just had this discussion in another thread that might be useful...

http://www.trifivechevys.com/showthread.php/3864-modifying-clutch-linkage?highlight=clutch



did you ever hear of any one using the American powertrain hydromax system with good results. you seem to know a lot about the hyd vs the manual setup.

Sorry, I have not. I built my own hydraulic clutch linkage to fit under the dash so I had to go through this entire exercise at that time. Maybe I need to put a kit together...:)

4429 4430

mikes55
05-12-2015, 08:05 PM
thanks so much for the info. when I bought the complete 5 speed set up I purchased the hyd TO bearing set up cause they told me it would be easier to press which is what I wanted. I had a zoom dia 101/2 PP with the least force to push which really isn't that bad to press. I had to change to a more spline disc so they said I should put an 11 inch science friction which they sell so I bought that. does an 11 inch take less force to push than a 101/2? I hoe the 11 inch dia is as easy to press as the zoom. so if the manual which is all brand new from danchuk will be the same as the hydromax from American powertrain I should just use manual and I wont have to worry about master cyl bracket hitting rag joint. plus since I read your post about leakage I have been searching the internet and I don't see to many good reviews about them. seems the orings don't last too long.

chevynut
05-12-2015, 09:43 PM
Here's the way I tried to explain it in the prior thread that I linked:

"To disengage the clutch you have to push X force over Y distance at the throwout bearing. Force times distance is work. The fork and all the other linkage just change your leverage, but you still have to do the same amount of work.

So let's say you need to push 500 pounds at the throwout bearing and it needs to move 1". That's 500 in-lb. Let's say you only want to push 50 pounds at the pedal....you need to move the pedal 10". All the linkage is used for is to get that leverage, and to change directions.

So if you want to lower the force, you have to increase the distance and vice versa."

So I don't see how a hydraulic TO bearing allows you to get less force at the pedal. If it does lower the force (via a larger bore than the MC), you get less travel at the TO bearing. You need a certain amount of TO bearing travel to disengage the clutch per the link I referenced above.

Again, per the prior discussion you might be able to do some optimization of the TO bearing travel and lever lengths to lower the force some, but I'm not sure. GM may have already done that with the mechanical or hydraulic setup.

Read some of the clutch stuff on the Novak site, it's every educational.

http://www.novak-adapt.com/knowledge/clutches_etc.htm

markm
05-13-2015, 06:43 AM
A diaphragm pressure plate takes less force than one with levers (don't remember what they're called).

Most Chevys with 3 finger clutches are Borg & Beck, the more round ones with 3 levers are Long style primarily in Fords. Have no idea about Mopar junk. In todays world its hard to find anything but Diaphragm. Back in the day they were junk, however, the there are some great new ones on market that take 5000 rpm clutch releases and like it.