new here.

my clutch has no pressure when i press it down and it won't change into any gear.
i'm pretty certain my push rod is leaking.
there is ZERO fluid in the reservoir.

3 questions.
Change the master cylinder?
dot 3 brake fluid? or dot 4 (which i already have)?

 

Dot 3 and dot 4 can be interchanged, or even mixed with each other.

NOT SO Dot 5 fluid.

 

Go with Dot3. It attracts less moisture over time.

 

A clutch hydraulic system doesn't have to worry about the boiling point of its fluid as the clutch slave cylinder doesn't have frictive heat being transferred to it unlike disk brake calipers. This means that any DOT 3, DOT 4, or DOT 5.1 compatible fluid will work (NOT DOT 5). Some parts stores even carry 'manual clutch fluid'.

These are all acceptable for this task.

Boiling points - Dry / Wet (3.7% H2O)
DOT 3 - 205C / 140C
DOT 4 - 230C / 155C
DOT 5.1 - 260C / 180C

Quote from Bendix (https://bendix.imgix.net/part_drawin...-PRJ-02727.pdf)

"Often not mentioned is the effect of the different DOT
4 formulation on the brake fluid behaviour. DOT 4
absorbs moisture at a slower rate than DOT 3 but
is more susceptible to suffering a drop in its boiling
point.

Typically a DOT 4 brake fluid will suffer a boiling point
drop of 50% once it takes in 2% moisture while a DOT
3 brake fluid would only lose 25% of its boiling point
at 3% moisture contamination although it takes in
moisture at a faster rate. This suggests that DOT 4
brake fluids offer more stability and safety for longer
but would need to be replaced at the recommended
OEM intervals before it suffers a substantial drop in
boiling point"

 

love that research Bunny.

you're not a Bunny in the Bay Area are you?

 

Did you check for signs of fluid leaking out on the firewall, both in the engine bay & inside the cabin? If you've got power brakes you'd see evidence of a brake fluid leak on the bottom front of the booster.
If not you've got a major leak somewhere else. Best to inspect the entire system.

 

BTW i fixed this long ago.
i replaced the master cylinder and have been back on the road for weeeeeks.
hurrah

 

Not in, but not far.