No.

Is the small hole supposed to be in the filler plug as a vent, or is it a defective plug?

Dan

Master cylinder caps have a hole as a vent. It sounds , from your description, as though you need to take your cylinder apart.

Yep, it's coming back out this weekend when I get a chance. If I accidentally overfill it, when I am screwing the cap back on it squirts out the vent hole a little. I did not really explain that right, I do not mean it just squirts out when you pump the pedal. Still, something must not be right so I'll take it out and take it apart again this weekend. Thanks again as always for all the input. Eventually I'll get there.

Dan

Here's a Ford MC. They're all the same.

Notice, when you start motion, the bypass port is open, allowing some fluid to 'backup' before the cup covers it. That's where your oil is coming from. It is normal. Notice too, there should be an air gap between the fluid and the filler cap. Your pedal guy is pushing too fast, causing fluid to squirt out. Have him slow down so the fluid will stay in the reservoir.

I'm thinking the inlet valve may be in backwards, which would push the pressure up through the cap instead of through the line.

Those persuaded against their will are unpersuaded still.
Can't fix stubborn

The valve in the end of the master cylinder is called a residual pressure valve.

It is designed to maintain a slight pressure on the wheel cylinders.

They found out, the wheel cylinder cups would leak a little if there was no pressure. So they keep a little pressure on the system to hold the cups tight to the cylinder walls.

Since 1975 replacement wheel cylinders have springs inside that do the same thing, so you no longer need the pressure valve on new cars.

It also stops fluid from draining back to the master where the master is lower than the wheel cylinders as on your car.

I've tried it both ways and go with the way that works best. So far no one has come up with a reason to do it the other way except "the book says so".

Unfortunately I live in reality land not fantasy land. This makes me hard to persuade unless you have evidence.

Dodge Deluxe, you have a PM, click on the blinking flag at the top of the page.

Okay, I FINALLY got brakes. It ended up being the front hoses, totally clogged and blocked, could not even blow any air through them. I put on two new ones and voila, I have brakes. Got them all bled, good solid pedal. Didn't have any brake lights though. Would not light when I stepped on the brake pedal. I jumped the switch and they would light, so figured switch was bad. I installed a new switch and now I have brake lights.

Dan