Low fluid in the master cylinder. Line restriction. Proportioning valve malfunction.
check fluid level
Open brake fluid reservoir for the brakes - make sure it is full of brake fluid - put lid back on reservoir then pump the brakes then hold the brakes on - have someone open the bleed screw on the brakes and let the air and oil out and close it again quickly and repeat until the air bubbles stop in the brake fluid, also checking to make sure you do not run out of brake fluid before you finish bleeding the brakes.
attach a hose to the nipple and have it go into a canister with fluid already in it this will keep the fluid from sucking back up
The reservoir with the lesser fluid capacity is for the rear brakes since the front calipar pistons require more fluid therefore they require the larger of the two.
hydraulic brakes work on hydraulic fluid the system is filled with fluid, all air is bled out of the system so only fluid remains thru valves and other components the fluid is displaced when when the breake pedal is pressed on each wheel at the brakes are some moving parts ,on drum brakes these are brake shoes and cylanders on disk brakes these are brake pads and calipers when the fluid is displaced thru use of the pedal these parts are pushed out by the fluid that ahas no where else forcing the pads or shoes against the brake disk or drum when pedal is released the fluid goes back to reservoir releasing pressure on parts at wheel which releases brakes
You may have a bad master cylinder, or proportioning valve,Does the vehicle have Antilock Brakes (ABS) ? Please let me know.Ben
leaky brake cylinders, leaky brake lines
what you have could be one of three problems. Check your reservoir to see if it has plenty of brake fluid, bleed your brakes,they may of lost the fluid while changing brakes. Also, if you have a vacuum leak it will cause your brakes not to work. Or it could be your master cylinder or your vacuum booster that has went bad. brewski
yes it is for wet brakes
The brake caliber is sticking if it has rear disc brakes. The rear wheel cylinder is sticking if it has rear drum brakes. Replace both rear units and then drain all the old brake fluid out of the system and replace it with fresh fluid. Bleed the brake system.
Brake Fluid.
the rear brakes are grabbing. the linings may have fluid on them from wheel cylinder leak or dust buildup. sanding the shoes may help .