Brake pipe male unions

The causes and remedy for brake jamming:
As a first aid, loosen and then tighten any one of the front wheel bleeding nipple. This will free up the brakes.
- Front calipers pins jammed. (Re-grease the pins with graphite grease)
- Front calipers pistons jammed. (Remove the caliper one by one, do not remove the brake pipe, depress the brake pedal only one time then release, lift the caliper boot at one side with abrupt tool, just as we lift up our eye lid with thumb and index finger, pour few drops of brake oil DOT 3 into the boot, push back the piston to allow the caliper to fit on pads.
- Rear wheel's pistons jammed. (Free up the pistons, inspect the brake washers, replace rear wheel cylinders if brake washers are found swollen).
- Brake master cylinder defective. The brake jamming problem often arises when the brake master cylinder washers swell up due to aging or using wrong grade of brake oil. In such cases the washers expand and block the return line of the brake oil. If so, replace the brake master cylinder with original one.

Check the inside of the tires to see if you find any brake fluid, some flex pipe going to the front calipers or rear wheel cylinder might have busted.

Check the brake fluid level in the master cylinder. If it's low or empty refill it and check for a leak. If the master cylinder is full of fluid the cylinder itself could be bad.

BY TRUCK HAVING ABS BRAKE.YOU NEED A SCANNER TO BLEED BRAKES THE SCANNER HAS TO RESET OPERATION OF THE BRAKE HYDRALIC SYTEM BEFORE YOU CAN BLEED SYSTEM.

First of all determine where the leak originates. At the outset make a mental note that the brake fluid will need bleeding at some point since if the fluid can leak out it is likely that air can bleed in. Air in the brake fluid is to be avoided as it impairs good brake function. First of all get the whole area clean. Use a small wire brush to remove all loose corrosion. Now check that there is plenty of brake fluid on the reservoir container above the brake under the hood, top it up as needed. 1) Bleed screw : Have a friend apply pressure on the brake pedal and undo (yes undo) the bleed screw just a quarter turn. Release about a quarter of a cup of fluid and then re-tighten the nipple before (this is important) the pressure is taken off the pedal. Clean everything with a cloth and tighten the bleed screw no ore than an extra quarter turn if this was the source of the leak. Check by standing on the brake pedal. 2) Caliper union : The flexible hose screws directly into the caliper and if it is leaking at the caliper just give it an extra tighten and then carry out (1) above. 3) Pipe Union : the other end of the flexible hose goes through a bracket and connects with the metal brake line. If tightening here, hold the metal junction of the flexible pipe steady and then tighten the brake line union nut. Do not be tempted to just tighten the nut on its own as the junction is liable to rotate within the bracket. 4) Brake pipe : Most brake pipes are made of steel (??!!) which as we know eventually corrodes. Most corrosion of brake pipes occurs either at unions or at brackets where water and salt can get to work. The only recourse is to change the brake pipe for a new length. 5) Caliper body : the seal between the piston and the caliper cylinder can sometimes be compromised by corrosion. You will need to remove the caliper/slave cylinder from the car to carry out a thorough inspection.

i would have to say the master brake cylinder is at fault. there are ports in the cylinder that allow fluid back into the reservoir. these ports may be clogged. or the brake hose/line is clogged. have you changed the brake hose?

i shall help u by telling the procedure. first remove the brake cable from the caliper. now check for the dusts if any and re insert into the disc caliper now bleed the brake master cylinder. strongly kick the brake.keep it in pressed condition and pour in the brake oil. now release the brake pedal and push it for two times and then release.now the oil will be evenly distributed into your master cylinder. To be noted that connection goes directly from brakes master cylinder to the brake pedal. from the brake master cylinder the connection goes to the two wheels(front).check for any oil leakage.

Hi,
Try bleeding the front brakes a little and see if they are holding pressure. If they are, it could be an adjuster problem, or fault with the master cylinder.
If there is no real pressure when bleeding - It's most likely a siezed piston or siezed caliper.
I presume the Brake pads and Discs are the correct type - as there are often many different models fitted, so identification is imperitive. Some are a few MM above others. Worth a double check.

You will need to bleed all the braking system via the bleed screws located on the front calipers and rear brake cylindersto clear all the air out of the system. Make sure you keep plenty of fluid in the master cylinder

Did you try changing front brake flex pipes, sometimes depending on age of vehicle the pipes can collapse from the inside when brakes are pressed on the pressure is forced down but there is no force to release pressure when let off sometimes causing the calipers to stick on. Assuming that both calipers are new and not second hand I would try replacing flex pipes.