Clutch pedal periodically does not return to normal height ..advised probable clutch master cylinder needs replacement..could it simply be hose? what is proper procedure to replace clutch master cylinder?

Most likely the slave cylinder is leaking. When a master cylinder leaks it usually wets the back of the clutch pedal and then disappears into the carpet.

Slave cylinder seals usually last almost indefinitely and when they fail it is usually due to fluid contamination, especially corrosion-causing moisture roughening the cylinder bore, though a long period working in the same range of movement can create a wear ridge in the bore. Replacing the clutch probably forced the cylinder into a new range of movement and the seal didn't like the wear ridge.

Replacing the master cylinder would probably pay dividends over the longer term...

Clutch "on the floor" is rather unusual... Most of all clutch spring is the feel of the pressure plate holding the clutch disc against the flywheel... but there is typically a pedal return spring that will take out the slack before ANY pressure is applied to your throw-out bearing.

Clutch MALFUNCTIONS will affect gear engagement... excepting (of course) clutch slippage.

For this trouble you need to take a quick look under the dash at the pedal hangers... and piston plunger that activates the clutch cylinder (typically on the outside of your firewall).

Now look at the clutch MASTER cylinder... the connecting HOSE and the SLAVE cylinder. Any fluid TROUBLE IS THE KEY to your trouble.

The ideal TROUBLE would be a split hose... but compared to a FULL CLUTCH rebuild all of these parts are cheap and easy to replace. Typically only requiring bleeding the cylinders... and you are back on the road.

If everything looks good you are MOST PROBABLY going to need a new clutch master, slave, hose and appropriate hydraulic fluid.

BUT if you have NOT found that TELL-TALE hydraulic fluid... you had better have an ASSISTANT operate the clutch pedal while you determine were that MALFUNCTION is located.

If the pedal is working the clutch lever on the transmission... you are looking at a SERIOUS clutch rebuild.

ALWAYS REMEMBER to work on level ground, chock your wheels and use good jack stands... like your life depends on it... before getting under ANY CAR... It does!

Good luck and here's a wish for a cracked HYDRAULIC HOSE...!!

it shounds as though your master cylinder might not be pumping any fluid.

Before condemning the clutch, check the clutch hydraulics. If the hydraulics are failing, the clutch it self could be fine. In your engine compartment, there should be two aluminum cylinders coming out of the fire wall. One will be attached to the brake booster and the other directy to the fire wall. Check the fluid level in the one at the fire wall. Top it off with Dot 3 brake fluid. CAUTION! Brakefluid will damage the paint on your car, so if you spill any on it or touch the surface with a fluid saturated rag, rinse it off with water!
If the fluid level is low, top it off and then pump the pedal rapidl rapiidly. It should come up to a normal height for a short period of time at which point you should be able to drive the car and see if the clutch it self feels normal, No slippage and no grinding of gears. The fluid loss is usually from the master cylinder. From inside the car, with a small light, follow the clutch pedal up to where the rod the pedal pushes can be seen entering the fire wall. Look for traces of fluid leaking out of the back of the cylinder. If the clutch master cylinder has failed, I usually recommend replacing the slave cylinder at the same time.

your clutch master cylinder is right beside your brake master cylinder. I would advise you to replace the master cylinder and the slave cylinder together. The slave cylinder is on the side of the transmission. The slave cylinder does have a bleeder screw on it after the parts are bolted in place fill with dot 3 brake fluid and open the bleeder on the slave cylinder until fluid starts dripping out. Then tighten bleeder then open bleeder and have someone push down on clutch pedal while the pedal is pushed down tighten the bleeder the release pedal. Repeat this procedure until you get no air and the pedal feels normal and you should be good to go. Good luck!

First, try bleeding it. Put a 2 foot peice of vacuum hose on the slave cylinder bleeder screw. Loosen the bleeder screw. Put the other end of the hose into a clear bottle or brake/clutch fluid. ( have the bottle about half full). Now, have someone pump the clutch by hand while you watch for bubbles in the bottle. When it stops bubbling, you have all the air out, and you can tighten the bleeder, and remove the hose, and refill the reservoir.
If it won't bubble, and no fluid comes out, your master cylinder needs replacing.
( P.S. - The slave cylinder is down under the truck. It's what pushes the clutch rod.)

Need to have it check could be clutch master cylinder or slave cylinder or hose from clutch master cylinder to slave cylinder.check brake fluid at clutch master cylinder sit next to brake master cylinder if empty could have a leak. fill and pump peddle and look for leak.

Replace both clutch slave and master cylinders, and bleed well. I've also had this happen.

yes

Cable Operated Clutch:
Stretched, frayed or binding cable, broken or bent pedal bracket, or cracked firewall can be the cause. Problems with a cable mechanism will often herald internal clutch problems as well. When something happens inside the clutch that requires extra force to be exerted on the clutch pedal, things break! Cables can also wear simply from age and use.
Hydraulically Operated Clutch:
Clutch master cylinder leaking or bypassing pressure, slave cylinder leaking, clutch flex hose leaking, pedal bushings worn or missing, or a cracked firewall can reduce the system’s ability to disengage the clutch. Rule of thumb: If the clutch master cylinder is bad, replace both master and slave cylinders as a pair. This will save you future heartache.