Thirim

Bought a gently used McLeod Street Twin.. the hydraulics came with it but were dry.
I am going out of my mind here. It won't bleed (bench bleeding)
I tried pumping the slave, using a mityvac, took the slave off, tried the mityvac on the end of the line where the slave goes.. nothing.
I even took the MC apart to see if it was clogged or something. I can't even get the MC to take fluid.
Inside the MC is a spring, a rubber "stopper" and a plastic piston.
If I extend the piston out past where it possibly can go, it will take fluid.
Since it never took fluid since I had it, I dunno if it's even together properly. Does anyone have any exerience with these?
To recap, I can't get the MC to take fluid from the resovoir unless I extend the plastic piston out further than it can go if the rod was installed.

Thanks

Chimera96

is it the Wilwood or Tilton MC?

Mine is the Wilwood. McLeod stopped using the Tiltons

What I did on the bench was rig the reservoir up higher than the MC with the tube going down to the MC and the braided line from MC to a plastic bottle (lower than MC). Pump MC by hand and keep replacing the fluid in reservoir as needed and pump MC until no more air bubbles come out of the braided line in the bottle. Get a large bottle of fluid as you use a lot bleeding

I then put the slave in a vice upside down with piston fully extended and put a small (2"-3" long) piece of clear plastic tube on the end of the fitting on the slave the braided line attaches to (roll pin). I just poured in fluid and "gently" did short pumps on the slave to push out any air bubbles and added fluid as needed. I now had the slave completely full of fluid and toped off even more as fluid was at the top of the small plastic tube I had on the end.

Now comes the time when you connect both MC & slave. I put my thumb on the steel braided line while it was still submerged in the small cut off water bottle I used, carefully pulled the small piece of tube off the slave and "quickly" connected the braided line to slave. Yeah I lost a few drops of fluid.

Now with a full assembled hydraulic I hung the slave to the lowest point and hand pumped gently but full strokes the slave and watched as very tiny bubbles came up to the reservoir I had rigged with a coat hanger above my work bench. Just a few bubbles came out.

With all the air out I could just touch the MC rod with my finger and see the slave rod move ever so slightly. Installed hydraulics as a sealed complete unit, basically just like stock hydraulics come.

The McLeod Street Twin needs the larger 13/16" bore MC for LT1 "pull" clutch

and a tip:

Some have also needed to shave about a washers thickness off the end of the "T" stud holding the clutch fork to get full disengagement (even after hydraulics are completely bleed). You won't know until you get the tranny in and adjust the rod on MC to know this. Not all cars need to do this. If you do, sucks as you need to drop tranny to get to it, which in my case is what I had to do.

what you don't want to do is fully extend the adjustable rod of MC, push clutch all the way down and start the car for the 1st time. If the T stud needs some cut off you would have the clutch fork jammed against the PP and when you hit the key your starter teeth will strip or you will FU the flywheel teeth. Slowly depress clutch first time with engine started to confirm you don't "buzz" the PP. With rear wheels off the ground push clutch in and put in gear. with clutch pedal all the way down your rear tires should not spin. If they do adjust rod a turn longer, try again, repeat as needed. If you buzz the PP with fork before you get full disengagement...you need to shave the T stud down. Again not all need to do this. Just giving you a heads up if you get to that point.

I also had no luck bleeding hydraulics with Mighty Vac

Thirim

Mine is the Wilwood I believe.
I've basically done what you said but I'll try again and follow your notes.
Thanks

Chimera96

if it is Wilwood you could call their tech line. They are located in Camarillo, CA IIRC

your MC look like this?

Thirim

negative.. looks like this.

Chimera96

that is the Tilton. The problem with those were the hole inside the MC the rubber cup passes over was not smoothed out so it cut the rubber cup. This would make it not work well and leak. IIRC McLeod offered a rebuilt kit for them which was not cheap for a rebuild kit but I did read on another forum a guy who kept having the issue found a brake cyl rebuild kit at NAPA for a few $ that was the right size

IDK if this is your issue but I do know people who had the Tilton had issues with them not holding pressure, apparently because of torn piston cups inside

The Wilwood MC kit is sold by McLeod and is 13/16" bore. You need the 13/16" vs the stock 3/4" MC for the "pull" Mcleod Twin clutch

Thirim

I *think* I got it bled.. I ended up pushing the internal pison out further than it could go when assembled and held the MC with the end pointing up (braided hose end facing up.) When it filled, I put the braided hose on and let it run out, then filled the SC and re attached it. I got a few bubbles out of it and now when I hold the SC in about half way and try to push on the MC it won't move, which tells me there is no air.
The rubber cup was chewed up a bit, and there was a little fluid behind it so I imagine that will be the next thing I'll be at.. sigh... lol
Thanks for the advice!

Chimera96

If that cup is chewed up...you may be dealing with this sooner than later.

when I bench bleed MC & SC as a assembled unit I had the reservoir up top to MC with braided line pointed down to slave with slave being piston down. Pumped the slave 1/2 strokes until no more bubbles coming up to reservoir. Given the nipple to reservoir is kinda in the middle of the MC I "moved/angled" it several times to coax any possible air bubble in the MC piston body out

Bleeding these is a PIA but doable. Hope you get your Twin working. It is one nice clutch

Thirim

I'm excited about the Twin, but doing the engine bay and a nice 383LT1 at the same time and I started late so I'm already in to very nice weather! ..So I'm excited to be able to drop the 383 in its hole! haha.

Thirim

Well the motor and tranny are back in and the clutch is not disengaging. The hydraulics are still messed up. It's not drawing fluid out of the resovoir.
Now I'm wondering if I shouldn't just buy a new MC and get it over with?
Hawks has a Tilton, but not sure who else has these?

Chimera96

well since you have a McLeod Twin you need a 13/16" MC...buy the Wilwood from McLeod. Especially if the Tilton Hawks is selling is like the model you have...they are chronic problem.

Tick sells a MC using a "newer" Tilton MC but IDK if it is 3/4" stock bore or they offer it in a 13/16" version

You need either a larger MC or a smaller bore slave for the street twin in a LT1 car. There was a guy using a stock MC and smaller bore slave IIRC for a Jeep or something he got for $50. He did have to make his own slave adapter mounting plate for it though.

IMHO get the McLeod/Wilwood unit and stock slave.

while you don't have this problem yet....if you do find that after getting the new MC, bleed it and then find your clutch fork buzz the PP before you get full disengagement...you need to cut off about a washer thickness from the bottom of the "T" the clutch fork is on. Many cars don't have to but if you get to that point, then that is the solution.

Injuneer

When the McLeod Street Twin kit first came out, it used the stock master and slave, and included a sleeve that needed to be installed in the slave. Worked OK. Some people had problems with the slave leaking, but I bought a used Street Twin, installed it in my Formula and it worked fine. After a couple years I switched to the TH400 and sold my T56, McLeod, hydraulics, etc. to someone for an A4-->M6 conversion, and as far as I know the sleeved setup worked OK for him too.

Trimming the fork pivot was also required by the instruction.

Chimera96

Yes there has been a few "revisions" on the street twin over the years. I suspect the sleeve for the slave was meant to reduce its bore size effectively giving it more stroke with a stock 3/4" bore MC

Then they switched to the all metal MC which was a Tilton (like what the OP has). People reported having MC failure due to torn rubber piston cups because the cup moved over a hole in the MC which was not chamfered.

Now they offer a larger MC, 13/16", made by Wilwood and you use the stock slave

All versions worked but had their problems for various reasons in hydraulics for some, not all. McLeod has been making the street twin since the 70's. The LT1 "pull" clutch may be the red headed step child of the twin but works very well when installed correctly and all the parts work as they should. Like many mods it can take some "adjustments" to get it right (cutting down the "T" bolt) but it is one very good clutch.