PLEASE HELP...Hydraulic throwout bearing wont work.. Billetproof next weekend

Long story here guys, hope you someone can shed some light on this... Trying to have my model A ready for Billetproof next weekend and this clutch problem is the only thing holding me up.. The motor is flathead with a chevy T5 trans. Bought a brand new Howe throughout bearing and clutch disc etc.. I am running a Wilwood 3/4 bore MC as suggested by Howe. I started with a very soft pedal that would go to the floor, bleeding and bleeding some more but couldn't get anymore than 1/4 of movement out of the bearing.. Out of frustration I went on to other things for a week or so. Now the pedal is very stiff stopping about half way. I had my wife press the pedal and when I crack the bleeder it goes to the floor, no air comes out and remains stiff. Im pretty certain my shim stackup is correct. Hope someone can help out here, really want to bring it to Billetproof this coming weekend.. Thanks in advance.

 

is it touching the fingers on the pressure plate when the pedal is not pressed in? to me it sounds like you may have too many shims

 

subscribe (and bump)

 

Have you talked to Howe and run this by them ?

Don

 

Just got underneath and looked and yes it looks like the bearing is touching the fingers on the pressure plate.

 

When you set it up and shimm it, you need to be very close but the bearing needs to rotate freely. Also the rod length is very critical. When we first set ours up it wouldn't work, we thought the rod was not long enough so we changed it and it and still wouldn't work. We then shortended it a lot more. It has worked very well ever sense. Check all of these items out and it should work. Good luck.--TV Ps if its touching it wont work, you need to be able to make the bearing spin wth your finger.

 

yeah take a shim or two out so that the bearing free spins by finger. it sounds like you are already engaged to the pressure plate and not getting full travel out

 

It does turn but you have to push it a little, wouldn't say it spins very freely

 

Then it is to tight, you should be able to spin it freely. Take one thin shimm out and you will be fine.--TV

 

I surely hope you get it sorted out. Taking the trans in and out is the reason I nixed that and went to an external slave.


Ago

 

Answer to your problem. MADE IN CHINA

A friend had one for his corvette and ended up using all of the internal components in the old cylinder.

It was not the first time that his machnic had that problem.

 

Just in case, are you using a killer pressure plate? What is your clutch pedal ratio?

 

I will take some measurements of the pedal tomorrow to figure out my pedal ratio.. Thanks for all the replys guys.

 

I measured my pedal ratio and it is 4:1..

 

I would think the pedal ratio should be closer to 6:1.


Ago

 

I made an adjustable pedal assembly out of a set of Model A pedals and had the exact same problem. There wasn't enough throw when adjusted back when I initially started driving the car. I adjusted the pedals forward and lengthened the throw rod a accordingly and the set up performs flawlessly.

 

First thing to do when setting up a hydraulic clutch is check the specs for the travel length of the throw out bearing. Using the area and stroke, determine the volume of fluid required to get that travel. Then, using the bore area of your master cylinder, determine what the stroke must be to displace a volume of fluid equal to that required by the throw out bearing. Now address your pedal ratio to get the correct travel at the master cylinder.

Bob