Rear wheels not spinning. Front wheels spin when in 4 drive.

unlock your front brakes first. if it's front wheel drive, with locked front brakes, it would shift but wont run or you burn your transmission clutch. if it is not front wheel drive, if transmission shifts, rear wheels should turn or spin.

check the rear wheel sensor wires and sensors . IT appears that the ABS is receiving ( or not receiving a signal telling the unit that the wheels spinning) a bad signal saying that the wheels are stopped and so the fluid to the wheels is restricted to allow them to spin. Check the fluid level in the reservoir as there may be no oil in the section of the master cylinder for the rear wheels and that half is not working

you have bad shocks-and- or tires that need replaced-while car is setting try to push down on the rear and see if it goes down easily and then bounces when released-jack rear end up-try to spin tires and see if they spin freely-check tires for cupping or funny wear patterns-you also may have brake shoe that are coming apart and locking a wheel up without putting on the brakes-so lots of options here-hope you get it solved-cheers Denny

I do not think this is an abs problem but rather a out of round drum, this problem only happens when you are braking ? if this is the case then i would check the rear brakes.
First make sure the rear wheels are spinning freely, if you use the e-brake then make sure there is not a cable holding.i bad e-brake cable will sometimes not release the wheel or both rear wheels causing the brakes to stay on in the rear, they may not be on all the way but on to cause the rear drums to over heat and get out of round causing a bad pulsating when braking.
Jack up the rear of the car and make sure the wheels are free spinning, if they are not then you will need to find out if its a cable, bad adjustment or frozen wheel cylinder. If the wheels spin free then have some one step on the brake and see if wheels lock up then release the brake and make sure they spin. next is to do the same with the e-brake.If all is good then replace drums or see if they can be cut. The last thing would be if the wheels are free and the car shakes when driving along and not braking then you may have a bad tire or bent rim. good day.

The reason is, you have a rear anti lock brake system. The anti lock valve is located on the frame just underneath the brake master. It is called a RABS valve. Almost impossible to bleed. But it can be done. A dealer has a tool that plugs into the RABS valve which activates the valve constantly moving the valve back and forth. This will then push all fluid and air out of your open bleeder screws in the rear.
I did'nt go to the dealer. i was too stubborn. My solution was to lift the rear of the truck and place on jack stands. Pinch off the rubber brake hoses on the 2 front brakes with a C-clamp or non marring vise grips, this will keep all fluid from going to front brakes. Next adjust the rear brake shoes by tightening the adjuster on the rear brake drums. Tighten the brakes on the rear until the brakes start to drag and the tires no longer spin freely by hand. Attach a bleeder hose to the bleeder screw on the RABS valve, place open end of hose into a jar or canister of brake fluid, so as not to draw in any air. Open the bleeder screw. Start the vehicle up, put it in gear, and let the rear tires spin. (I got up to 25mph on my speedometer) Step on the brake while it is in gear and the tires are spinning. This will activate the RABS valve and cause the air in the RABS valve to bleed. Do this several times. Put vehicle in park, shut off engine, and close the bleeder on the RABS valve. Attach bleeder hose to right rear of the truck, place open end of hose in a canister or jar of brake fluid so no air gets in and open the bleeder screw. Start the vehicle up, put it in gear, and let the rear wheels spin freely. As the wheels spin, you press your foot on the brake pedal, this will activate the RABS valve, and effectively bleed the brakes. Do this a dozen or so times, tighten the bleeder screw and do the other side. Remove clamps from front brake hoses and you will be go to go. All this may seem a bit extreme, but it is the only effective way to bleed a Rear Anti Lock Brake System on an early Ford. All the steps I laid out are necessary. You cannot skip one. The reason why the rear has to be in the air, is that there is a sensor mounted to the rear differential that senses wheel spin(or axle spin), this goes directly to the RABS valve and tells it that the tires are moving at a certain speed, and to activate the Rear Anti Lock Brakes when the brake pedal is depressed. It will not activate if it does not sense movement. The reason for pinching off the front brake lines, is that there are needle valves in the master cylinder and they will send too much fluid to the front calipers, and stifle or hinder the amount of fluid needed to go to the rabs valve and ultimately the rear wheel cylinders. It seems like a lot, and it is, but I did it and it works. Good luck

abs systems do not lock on the brakes
they release the brakes when the wheels stop spinning and when the wheels start turning again apply the same brake pressure as before the wheels stopped spinning
check the proportioning valve to the rear brakes to ensure that it is not acting as a one way valve and that is causing the problems
if the compensating port in the master cylinder for the rear wheels is blocked that also will lock the rear brakes

try adjusting the rear brake shoes but.....spin the rear wheels first is u get the feeling of the shoes grabbing then releasing ( the tire gets loose then tight as u rotate it) u will need to have the drums cut on a brake lathe or replaced...when u have this done , then adjust the rear shoes until u get a slight drag on the rear wheels..go pump the brake pedal to seat the shoes if the wheel spins free adjust the shoes more an repeat until they have a slight drag after pumping the brake pedal

e-brake pedal should go farther- is either out of adjustment or cable frozen- secondly sounds like only front brakes receiving enough pressure to "activate" properly- bleed all four brakes starting rear pass,then rear drive ,then front pass, then front drive- use plenty of fluid- bleed till fluid is clean without bubbles- will that long at first- this will insure not bubbles and no moisture- if a pro valve dies,you would have more problems- pedal would be really soft,would have both a brake light and abs warning lights

The pulsing is usually caused by a warped rotor. Rotors warp from quick stops and rapid braking techniques. It could also possibly be a weakening Master cylinder or a leaky diaphragm in the brake boost, but this last would be accompanied by a hissing sound when you hit the brakes. To check the rotors, block the rear wheels and raise the front until the wheels are off the ground. Spin the wheels individually by hand slowly - they should roll smoothly. If they do , have a helper apply very light pressure to the brake pedal with the engine running and again spin the wheel. With the wheel spinning, have the helper apply increasingly more pressure to the brake pedal until it stops the wheel from turning. Now have them back off the pedal slightly so you can spin the wheel again and spin, looking for uneven rolling. Check both front wheels to show which rotor is warped. If either is warped, you'll need to have the rotors resurfaced ( turned) and replace the pads both sides.
If they turn smoothly through all of the tests, apply solid pressure to the brake pedal until you can't push it any farther and hold that pressure. Watch the pedal for sinking. If it sinks, then you either have air in the system or a bad Master cylinder. Bleed the brakes first before you replace the master and do the pressure test again. If you don't find anything at this point, start the engine and do the brake pressure test again. If the pedal sinks, then you may have a vacuum leak in the booster and will need to do a vacuum test on the booster to make sure, since that job is usually hard to do and may be costly, depending on the style of booster you have.
Hope this helps!!

rock the car to brake them free the brakes are locked up