Clutch Master
It is obvious air is getting in the line between the slave and master cylinder.
My clutch master failed because someone put something other than the proper fluid in the reservoir. I use only clean - clear - DOT3 brake fluid. Anyone placing engine oil by mistake will discover just how difficult the clutch is to operate - only superman could press the pedal to the floor in cold weather - AND he WILL bend the clutch pedal!!!!! (I know from experience) Moreover, the continued operation of the clutch with improper fluid will likely cause air and fluid leaks in and around the clutch master cylinder.
Fluid leaks may be evident on the interior of the floor mat or carpet. Such leaks may appear insignificant - yet should NEVER be present either inside the vehicle or under the hood.
I can tell you from experience that good bleeding is essential. My replacement master cylinder came with instructions suggesting that the clutch master MUST be bled before installing it - in a close the vertical position with the actuator rod pointing upward. If bleeding is attempted to a clutch master that is installed in the firewall, this is NOT POSSIBLE.
If you decide to REPLACE your clutch master cylinder, you may find these steps helpful: Remember to chock wheels for safety sake. I used jack stands to raise the vehicle off the ground in the front to give ground clearance for my considerable belly to slide under the vehicle to bleed the line after the work is done.
1) remove two 8mm bolts holding the plastic reservoir to the fender well just behind the starter solenoid. (Do this FIRST)
2) remove the spring clip holding the actuator rod to the clutch pedal.
3) remove the switch and connector from the actuator rod.
4) remove the clutch master cylinder by rotating it about 1/8 turn so that it will slide out of the square bracket that holds it in place. Once released from the bracket, it can be pulled from the firewall from under the hood. Patience is required since there is a large rubber grommet around it when it penetrates the firewall.
5) remove the hollow pin holding the line to the output connection of the clutch master cylinder. I used an appropriately sized nail and small "c" clamp to aid in the removal of the pin - although I am confident that is an elegant tool just for this purpose.
6) remove the now loose clutch master with attached reservoir. Wires and other accessories will make this difficult - so be patient. I removed a number of bolts holding lots of things that got in my way.
NOW REINSTALLATION - this is where things can get tricky. Its essentially the opposite of removal. Once you have the new clutch master connected to the line going to the slave (remember to install th hollow pin holding it in place), you must bleed the new master. Go ahead and install the actuator rod. Use 1/4" (6.5mm) plastic clear tubing over the slightly opened bleed nut and a reservoir. Fill the reservoir and while holding the new clutch master vertical, press the actuator rod down inside the master. Keep topping up the reservoir with fluid as you repatedly do this. Fluid will seep out of the bleed nut through the clear plastic tubing. I used an empty glass jar about 1/3 full of fresh fluid. I taped the tubing so that the end of the tubing remained well down into the jar - below the fluid level. As I repeatedly pressed the actuator, fresh fluid is pumped into the slave cylinder - expelling fluid plus and trapped air. If the discharged fluid from the slave is not clear, continue pumping the master cylinder actuator (and of course refilling the reservoir) until the discharged fluid is totally clear. This will assure you have flushed the entire clutch hydrallic system with clean fluid. Once you feel all the air is out of the system and only clear fluid is discharged, tighten the bleed nut assembly.
DO NOT YET ATTACH THE RESERVOIR to the fender well just yet. You will need to install the master cylinder through the firewall and align the actuator rod and clutch master cylinder through the bracket. This generally requires a person (a contortionist is helpful!!!!) who can fit under the steering wheel and lie on his or her back to help guide you while aligning the cylinder through the square shaped hole of the bracket. I literally had to climb under the hood to reach far enough to twist and manipulate the master into place.
Once aligned and secured into the under dash bracket, the switch is reattached around the actuator rod and the actuator rod is reattached to the clutch pedal using the spring clip to hold it in place.
Replace anything you may have loosened under the hood and finally attach the reservoir to the fender well. I then placed jack stands under the rear making sure that the rear wheels were about 2" off the ground.
Starte the engine and check to insure that the rear wheels turn when letting out on the clutch and they should stop turning when pressing the clutch to the floor. If all works as it should, turn the engine off and remove the jack stands. If the clutch pedal feels "spongy" and requires pumping, you probably did not bleed it sufficiently and you should try to bleed it again. The pedal should not be spongy at all - when its properly bled of any trapped air. The clutch pedal pressure in my case took a bunch less effort to operate than before I replaced the clutch master cylinder - but worked flawlessly afterwards.
I do hope this helps..
BTW - I have a 2 door 1997 with the 4.0L pushrod (OHV) engine. When using87 octane (regular) gasoline I typically see 24 mpg around town and can if I am careful see as much as 30.25mpg on 150mi trips that I regularly make. I keep a log of every drop of gas this explorer burns. My wife gets about 5 mpg less than this - because I am extremely patient when accellerating, listening to engine speed and plan ahead to avoid heavy braking when possible. She would make an excellent race car driver. LOL
