1999 Explorer Sport 4x4 V6

Car gets driven regularly, Had to do some work to it last week to try and get it to pass inspection, Pass. Ball joints where blown out. I replaced the lower, the upper i didn't do because i couldn't get the ball joint out of the upper arm with just a hammer and a fork so im just going to order an upper arm to make my life easier. The upper ball joint I have looks like it will only fit the drivers side anyways.

Got it back together and took it for a test run down to the store and back, noticed a big kerchunk when i was manuvering around the parking lot, thought something came loose, inspected. nothing. Found out it was the brake pads on the drivers side were gone. Went to back up one day and pads crumbled off the rotor. I overextended the pistons in the caliper and lost most of my brake fluid.

Jacked it up, was able to press the pistons one at a time back into the caliper. Did NOT open bleeder valve prior. Installed new break pads, topped fluid off, bled front drivers side from the banjo bolt, bleeder valve rusted in caliper good. Well I still can't get my brakes working right. Thought that mabey air in line. Bled front brakes multiple times, bled entire car multiple times. Bleeder valves on rest of car fine. Rear brakes seem to work fine.

Went back and bled drivers side front over and over again from the banjo bolt, fluid spurts right out no problem. No fluid leaks anywhere. Tried unsuccessfully to work loose the bleeder valve on front drivers side encase there is an air in the caliper.

With car off brakes pump up normal, with car running, pedal is softer but still somewhat stiff, minimal stopping power at very low speeds. Seems adequate pressure until pedal is halfway depressed then from that point it gets softer and slowly goes to the floor. While moving brake pedal is very soft, no stopping power but as car starts to slow pedal gets stiffer as it is being pumped but still going to floor. Fluid is topped off, no leaks.

I am wondering if possibly I damaged the master cylinder when I installed the new brake pads? When the car is moving I can see the rear brakes clamp down fine when applied.

What am I doing wrong. Breaks were fine previously other then it needed new front pads. So it cant be the booster. I bled the entire car multiple times incase air was pumped into the system when the pads initially fell off sprayed fluid from the caliper piston.

 

If you didn't ask what are you doing wrong you may have received a different answer.
What you are doing wrong is ,you are doing a butcher job on your brake system.
If you can't get the bleeder open on the caliper to get all the air out of the caliper, replace it. So many people are doing peacemeal work on brakes and taking chances they are a hazard on the road. I know times are rough for a lot of us , but with crap work on brake systems they can get a lot worse.
You don't only need a rebuilt/exchange caliper , you also now need to replace the master cyl. Why ? When you used your daily depended upon daily driver the brake pedal only went down to a certain point in the master cyl. When the pedal went all the way down as you lost the brake fluid the cups in the master became scored and now will not hold pressure after riding over the junk in the master cyl. You are trying to help yourself and that's good, but you are trying shortcuts and that's not good.
Please, if you can, replace both the master and the caliper you cannot bleed properly and you should be OK. You depend on that vehicle so why not do the job right !! At least that will be one more vehicle on the road with properly functioning brakes.

 

Got the caliper bled. replaced nothing. works fine now. thanks.

 

I may have come down a little hard on you, but there is no way bleeding a caliper is going to correct a sinking brake pedal.