I was pulling out of Subway and I went to slow up to merge onto the road and suddenly my brake pedal dropped completely to the floor! No pressure unless the pedal was flat against the floor board, and even then it was only about 30 percent braking force! I had to get back from my lunch break for work, so I limped it a mile up the road, using the parking brake and engine braking when necessary, but it was terrifying! I have full brake booster functionality. By the time I pulled into the work parking lot the brakes were 100 percent gone. I literally overshot the parking spot I chose because the brakes didn't do jack ****. I got out and popped the hood. The master cylinder resevoir was bone dry. A week ago she was completely full. I've never had any brake problems before. I grabbed half a pint of brake fluid from the truck, poured it in, it bubbled down in there and disappeared, started the truck and tested the brake, still 100 percent shot. I rechecked the MC resevoir, it was empty again. I was able to somewhat safely limp home that night, but I parked the truck ever since and have been using the camaro as my DD until I get this resolved. I'm stumped. I noticed a big *** wet spot on the road beneath my driver side front tire, about 6 inches in under the truck, and a smaller wet spot on the driver side rear. My suspicion is I ruptured a brake line or hose. What do I do? How do I look for this leak? If it's a brake hose going from the line to the caliper (please be that, please be that, PLEASE BE THAT!!!), that job seems the simplest and cheapest to perform, but how do I completely refill and bleed out the system? I've never had to refill and bleed an entire system before, only the back wheels on my old integra when I replaced the calipers.

1999 Ford RAnger 3.0 4wd, 5MT

Cliffs:

Sudden loss of brakes at 90 percent failure
3 minutes later brake failure was at 100 percent
Empty master cylinder, partially refilled it and still no brakes, MC was empty again
Wet spots under front and rear driver side hub assembly, the front wet spot being much larger
Parking brake still at 100 percent functionality

 

Well you have a broken brake line, there are two systems, front and rear, so you don't lose all brakes right away when there is a leak or blown line.

Having some brakes, the 10% at first, was the last of the fluid, 0% was all fluid gone from master.

It is obviously pouring out somewhere, since the loss of new fluid happened pretty fast.

I lost the brakes on an older Ranger coming down a hill, that was scary, yes parking brake was a real asset then, lol.

I had a rusted out rear main line, it fed both rear brakes.
Because I would have had to drop the fuel tank to get to the break in the line I just ran a new line, wasn't hard.

It will be squirting out of a leak that size, so put in some more fluid and have someone press on the brake pedal(engine off)

To bleed the whole system you fill up the master then start at the wheel farthest away from master, so passenger side rear, then do drivers side rear, then passenger side front and drivers side front.
Keep topping up master.

If brakes feel spongy when done, then do the bleeding again in the same order, there may be some air in the long lines in the rear

 

They say cars from 40 years ago until now have a dual setup, where the LF/RR and RF/LR are in their own circuits so if one circuit fails you can still safely stop. However, I had NONE of the four wheels with braking power? Is there an explanation for this?

 

Having worked on and pulled apart many older and newer brake systems I have never run into a system like that.
That would make braking squirrely as heck, just normally.

There used to be, years ago, two reservoirs in the master, front brakes and back brakes each had their own reservoir, and a built in proportioning valve.
So if front or back brake line or slave leaked or had a broke line the other system would still work.

Most vehicles now use the much less expensive single reservoir masters and have a "brake light" on the dash that will warn you when brake fluid is low.

And with the newer ABS systems and material used for lines and hoses a bad break in a line/hose isn't that common.



Proportioning valve is different for each model, on a pickup usual setup is 70% to front 30% to back, on cars 60% to front and 40% to back, that is when you step in the brake pedal 70% of the pressure goes to front brakes
But that part doesn't really matter.

 

Is it difficult to replace Ranger caliper brake hoses?

 

No not at all, couple of open end wrenches, flare nut/line wrenches are better if available, they are like a box end wrench with a slot, so wrap around the nut more for a better grip.

It is better to remove caliper when installing a new hose, so you can rotate the caliper when tightening the connection so hose doesn't kink.

 

So what is the proper procedurr for refilling and bleeding an empty brake system?

 

As posted above.

To bleed the whole system you fill up the master then start at the wheel farthest away from master, so passenger side rear, then do drivers side rear, then passenger side front and drivers side front.
Keep topping up master.

If brakes feel spongy when done, then do the bleeding again in the same order, there may be some air in the long lines in the rear



And it won't be empty, only the wheel with the leak would be empty, so if no air comes out, move to next wheel

The reason the brakes quit is because master was empty, because, I assume, 1 wheels line had a leak, the other 3 will have fluid, but couldn't work because when you stepped on the brakes the master was pushing air not fluid, so..........no brakes

 

If the master cylinder has air in it, you may have to bench bleed (or equivalent) to get the trapped air out of it. The angle of the master can trap air and normal bleeding may not flush it out.