Gun Jam

Im with racer dave on this.

The lines have air in them because vac bleeders in general that most people come across are crap.

Try it the old sk0ol way with two people. shove the pedal to the floor hold it there then crack open the bleed line.

racer_dave

I'd start by doing a good pressure bleed. If you're alone then buy some speed bleeders. I use them on all my racecars because I'm normally out in the shop late at night when I don't have any help.

Other thoughts...

With the TOB fully compressed and no pedal pressure the TOB is touching the clutch fingers? So in essence it will be spinning 100% of the time? The 'free play' there is what I normally set between .040 and .060. If McLeod says different then OK, but I always leave some grace there because I don't want my TOB spinning all the time(just wears it out faster). Of course I'm running the engine to 7900rpm too. But that bit of free play gives some cushion in case the clutch fingers are not all at the exact same height. Yes, they are supposed to be, but not always, again we're talking about a .010 of an inch here. If they aren't then the difference could be pushing the face of the TOB a few thousandths of an inch. Like a warped caliper. It could cavitate the fluid and cause it to heat up. When it heats up and expands it will try to extend the TOB which in turn can cause the TOB to press on the clutch fingers, which will wear out the TOB even faster...

Be that as it may, when the TOB is fully compressed and no pressure on it, where is the pedal height? If it's too low, then you need a longer bar(extension) and if it's too high(up against the stop and partially compressing the TOB) then you need it to be shorter. Make sure the pedal has a spring to keep it up, otherwise, just the weight of the pedal might start to compress the TOB just a bit. It might not feel like it is doing it much, but again, we're talking very fine measurements.

Now, if the pedal height is good with TOB fully compressed yet pushing the pedal all the way down doesn't release the clutch then you need to look at the M/C bore size as it's probably too small. The pedal ratio won't matter here becasue we're not worried about the force it takes to compress the clutch, we're only looking at how much fluid is moved by the M/C and the distance the TOB has to extend.

Hope this describes more what to adjust.

67mustang302

FYI on the McLeod units, iirc the free play when installing is supposed to be .100-.125, but after bleeding the TOB will remain in constant light contact when the pedal is fully released. The bearing will spin freely with no load on it, which is fine; and the free play setting is to allow the clutch fingers to push the TOB back as the disc(s) wear. The clutch fingers push the TOB back to it's resting position, where it should sit in light contact with the fingers.

Either the installed clearance is wrong, the master cylinder is wrong or not getting enough stroke, or the hydraulic unit itself is incorrect. The McLeod units should have plenty of extra room to work in them when in the proper application.

What master cylinder are you using? I'm running a new Wilwood .700 bore, which is about ideal for the McLeod 1300 types since it moves more then the needed volume, but has minimal pedal effort.