Hydraulic Clutch Installation

Hydraulic Clutch Installation

Installing the Hydraulic Clutch Setup

A few weekends ago, having made some major progress getting the Edsel into shape, I finally had enough small wins behind me to attempt the hydraulic clutch kit installation.  I bought the kit from Modern Driveline, the same folks who sold me pretty much everything else (except for the transmission) for the T5 conversion.  Having learned my lesson multiple times, I have a strong preference for buying complete kits from a single supplier so as to (hopefully) lessen the chance that parts won’t play nicely with each other.

When considering a hydraulic clutch conversion, you have two options: a hydraulic throw-out bearing (internal) or an external slave with the stock fork and bearing.  The internal hydraulic bearing setup is a cleaner installation and requires even less clearance than the external slave does, though the major bonus to the internal setup is that it’s self-adjusting.  The major downside to the internal/hydraulic throw-out bearing?  You have to take the transmission out to install it.  Oh, and lest I forget to mention, it’s also $100 more than the external setup.

Not in the mood to spend even more cash, and especially not in the mood to take the transmission out, I chose to go with the hydraulic clutch external slave cylinder.  The external kit is basically a bolt-in install with the MDL aluminum bell-housing, in fact the holes to mount the bracket were already drilled in mine.  The downside is that I’ll need to adjust the clutch regularly as the disc wears, but it’s an easy adjustment.  The goal is always zero lash, so you press the slave in until it bottoms out, then turn the outer nut as tight as you can with your fingers against the fork (no wrench!), then tighten the lock nut.

I got through installing the slave on a Saturday that weekend, and then on the Sunday I worked through installing the master but didn’t finish.  The master mounts against the firewall tight against the fender splasher, and it requires drilling holes, making templates, drilling more holes, and some serious fiddling.  Eventually I got the thing installed later in the week, but it took me until this most recent weekend to reinstall the power brake booster and master, connect the lines, and bleed both the brake system and the clutch system.

Getting the power booster back onto the firewall was an exercise in futility, which I’ve written about before.  Literally it took me three nights of cursing, straining, bleeding, and cursing some more.  There wasn’t any room to maneuver in there before, and with the clutch master now it’s even worse.  Eventually I remembered the tricks and got the thing remounted.  Bleeding the brakes was easy.  The clutch system?  Impossible.

I followed the very specific instructions from Modern Driveline with respect to bleeding the hydraulic clutch setup.  I had no pre-load on the master, I gravity bled the system first, I filled the reservoir, I applied 8 psi air pressure, I waited for the second stream of bubbles, and I closed the bleeder screw as soon as the 2nd stream stopped. Still had air in the system.  Did it again.  Still had air in the system.  Gravity bled it again.

Disconcertingly, the clutch slave didn’t travel the distance it’s supposed to (1.2 inches according to the directions).  I only see 1/2″ travel.  So I know I’ve still got some air in the system.  But the clutch feel was really stiff once the slave moved…so I called Modern Driveline about it (they are super helpful and understanding), afraid they’d tell me exactly what they told me.

“Due to variations in clutch pressure plate finger height, the ball stud pivot in the bell housing needs to be adjusted out an extra .125 inches.”  So…the painful process I was trying to avoid?  Yeah, I’ll be taking the transmission out again sometime soon.