“Clutch Pedal On The Floor”

What has most likely happened is that the clutch hydraulics have failed, probably the slave cylinder.  Regardless of whether it was the master or slave that failed, it is always advisable to replace the master and the slave at the same time.  The slave is the lowest component in the entire brake/clutch hydraulic system, so it follows that any debris in the system is going to make its way toward the center of the earth…down.  That messes with the seals and the slave cylinder fails.

The installation of a new slave cylinder will make the master cylinder jealous, and it will fail soon after just out of spite.  So do them both at the same time.  Also blow out the line between the two to clear any debris out – some say replace it, but a bit of a clean with compressed air followed by some brake cleaner and more compressed air is normally enough to do the job.  There is a possibility that the flexible part of the line is partially collapsed, but I have never seen one collapsed.

I get my parts from Rock Auto..  The master cylinder is around $90, the slave cylinder is about the same, but at this writing in late 2023 they are showing the new line is out of stock.

Drain down the brake fluid reservoir before you start.  This is also a good opportunity to change the brake fluid and bleed the brakes, also clean out the reservoir.  New clean fluid and a good clean of the system is always a good idea, especially when talking about brakes.

To get to the slave, you have to remove the starter, so disconnect the battery.  Not a big deal.  The slave is found up and to the side of the starter.  Crack the hydraulic line loose before you loosen the bolts holding the cylinder onto the bell housing.  Install the new slave, and make certain that the rod in the slave cylinder properly engages the cup in the clutch fork.  You can see it through the inspection hole in the driver side of the bell housing.  Before fully tightening the bolts, thread the hydraulic line onto the slave.  Having a little movement helps with getting things lined up and avoiding cross threading the fitting.  Tighten up the bolts and the hydraulic line.  That’s it for now.

The master cylinder is located under/next to the brake booster.  The easiest way to get to it is to remove the emissions control junk at the top rear of the engine compartment – two small bolts with a 10mm wrench.  Just take the bolts out and you will need to disconnect one of the hoses, then just move it aside.  You will need a short 13mm socket with extensions and a universal joint to get to the two nuts holding the cylinder in place.  As with the slave, crack the hydraulic line loose before you unbolt the cylinder, and disconnect the feed hose from the reservoir.  Be careful as the plastic reservoir is brittle and you can break the spot where the hose attaches to it.  The passenger-side nut is the easiest of the two, as the driver side nut has part of the wiring harness in the way.  Remove the two nuts, remove the cylinder and you are officially halfway there.

Leave the plunger in the old master as the new one has a new plunger rod.  Put the new master in place, then put washers on the studs – I use a magnet to get them down there.  Now take your socket, put some grease in it and the new nut, and fish the tool down to the stud to thread it onto the stud.  Repeat for the other side.  I like to thread the hydraulic line onto the master cylinder before tightening the nuts fully so that it has a little movement to help me get the line correctly threaded easily.  Start the threads on the line, then tighten the nuts.  Tighten the hydraulic line and hook up the feed hose.  From there, put the emissions stuff back in place.

Get yourself under the dash.  (I remove the steering wheel to make it easier to get down there and back out.) You will find that there is a rod hanging off the clutch pedal.  The pedal end of the rod is fitted over a post on the side of the pedal, held on with a clip – the same kind of clip that holds the hood side of the hood shocks.  Take the clip off, remove the rod.  You will see that the rod from the master cylinder is screwed into the part of the rod that goes on the pedal. Remove the old master cylinder side, then thread it onto the new master cylinder rod under the dash.  Adjust it so that the pedal end fits back on the post on the pedal, and you’re there.  Replace the clip, tighten the 13mm nut to hold the adjustment in place and get out from under the dash.  Note that you can adjust the “bite point” of the clutch by adjusting the length of this rod.

I use a pressure bleeder on our cars.  It is a canister with brake fluid in it that attaches to the top of the brake reservoir.  You pump it up to about 20 psi, then crack the bleeder to feed pressurized brake fluid through the system and force the air out.  No pedal pumping!  Do the clutch first, then bleed the brakes as normal.  I use a hose with a gatorade bottle so I can watch what comes out – when fresh fluid appears, you should be good to go.

Check the clutch pedal with the car running to determine if the clutch bite point is where you like it.  If not, you can adjust the length of the rod on the pedal to get it perfect.  There should be a little bit of free play at the top of the pedal, but again this is a “personal preference” thing that you can adjust to your liking.

Of course this job is best done with the car on a lift.  If you don’t happen to have one of those in your garage, make sure that you properly secure the car in the air with GOOD jack stands.  Wear safety glasses when taking the slave cylinder out as it will still have brake fluid in it and will leak out as you disconnect the line and take it out.  Brake fluid in the eyes hurts!

Best of luck!