Bad Vibration

i have a 2001 escort sedan whenever i am braking above 50mph there is a terrible vibration also when braking below 20mph there is a grinding noise what could be causing these issues

i have a 2001 escort sedan whenever i am braking above 50mph there is a terrible vibration also when braking below 20mph there is a grinding noise what could be causing these issues

Did you check your break pads, they might be worn out...

Did you check your break pads, they might be worn out...
the pads and rotors appear to be non warped and the pads are wearing evenly they are about 4 months old

some things you could check; is the caliper not bolted tightly to the steering knuckle? Is the hub nut tight? Are the lug nuts for the wheel all snug?
If there is a griding noise, it should result in some evidence of metal-to-metal scraping. By removing each front wheel, you can look on the inside of the rim, to see if the caliper has been rubbing on the inner part of the wheel.
And the old standby test.... With a front wheel jacked up off the ground, see if you can wiggle it. Grab it with two hands at the noon and 6 p.m. parts, and see if the wheel will move at all. Then do it with two hands, at 3 p.m. and 9 a.m. positions. There might be some movement, but it should Only be due to the steering wheel turning as you try to turn the wheel left-right.
Also have a look on the strut, where it runs near the tire. A broken strut may not be obvious.

Good post. I might add that the ball joints or tie-rod ends or the lower control arm bushings may be worn out. Get it fixed as soon as possible. What you describe could be a very dangerous situation.

there is no evidence of rubbing on the inside of the wheel or on the caliper any other sugguestions will be greatly appreciated

I would bet that the rotors are warped bad enough or the hub is bent enough that the caliper slides are causing the noise at slower speeds. I just had a hyundai the other day that and rotational grinding noise that ended up being a bent hub. It has abundantly obvious once it was running on the hoist. You could watch the wheel wobble quite a bit. New hub and new bearing and the noise was gone.

Another diagnostic technique: Drive along parallel & close to the back wall of some large industrial building, like a Walmart or Kmart. With the car window rolled down on the side facing the wall, driving thus will reflect sounds (like the grinding) so you can hear them better. After driving back in the other direction with the other window rolled down, hopefully you will at least be able to isolate which side of the car the noise comes from.

How many miles are on the car?
When was the alst time the wheels were balanced?
What brake pads were put in 4 months ago? For all I know, you used crap made in China.