Cavalier master cylinder

heck thebrake fluid level before you go any further ,

The brake hose is clogged. When under pressure from applying breaks, the piston is forced tight to the rotor. When released the fluid will not return through the hose because there is no real pressure. Replace the hose.
murf427

Hi there,

The pads are easy to change. You do not need any special tools. If there are no grooves in the rotors I would just put on new pads. Don't get cheap pads or they will squeek. I would strongly suggest that you flush out the old brake fluid. You will be amazed at how brown and gunky the old fluid is. Flushing the fluid regularly will help make your calipers and master cylinder last a long time. I like to use Valvoline Synpower brake fluid, it is a couple bucks more but it is DOT 4.

One last tip. When compressing the brake caliper piston you do not want to push the fluid back up to the system, because you might get some crud into the ABS module. Therefore, when compressing the piston, loosen the bleed screw to let the fluid flow out of the bleed screw.

This is how to get it done:

• Remove the old fluid from the master cylinder resevior with a turkey baster. Top up master cylinder with fluid.
• Remove the right rear wheel and bleed/flush the brakes with the old pads on. Top up master cylinder with fluid(important). Remove the caliper, open the bleed screw and compress the piston, close the bleed screw.
• Install new pad and caliper
• Bleed again. Top up master cylinder with fluid.
• Repeat on remaining 4 wheels RR, LR, RF, LF.

Glad to be of help!!!

If it's been 10days, I hope you got your brakes together by now. Sorry I'm late.
I assume you are talking about retracting the pistons into the calipers, so you can get them over the rotor. If they don't go over the rotor, the piston almost certainly is not all the way in the caliper housing.

I usually do one side at a time.
Remove or loosen the cap on the brake master cylinder under the hood. This insures that when you press the piston back into the cylinder, that the brake fluid can flow back into the master cylinder.
If you have both sides apart, make sure you temporarily put one side back together or block one of the pistons with a stack of pads or wood to keep it from popping out.

The easiest way to push the piston back in is to use a C-clamp and one of the old brake pads. Place the pad on the piston, and clamp it with the C-clamp. Tighten until piston is back in.

No C-clamp? Put the old inner pad back on and slip the caliper over the rotor. You don't have to bolt it down, or maybe just start the bolts to keep the caliper from moving around. Use a large screw driver or pry bar in-between the old pad and rotor and pry the piston back in.

Are the rotors worn? Worn rotors and new pads will sometimes cause this. The pad sits across the ridges and no matter how much you bleed the system the pedal just wont stiffen up. (See diagram. A - New pads, B - Rotor, C - Ridge)
If you did not install new pads you may also want to check the master cylinder seals. First bleed the system at the pipes that connect to the master. If the rotors are ok, you've bled the master cylinder and the problem persists then replace the seals or the complete master cylinder.

the new one will not have siezed pistons just push the pistons in and it will push in ok

Hi Friend: On your vehicle you'll have disc Brakes Front And Rear.Your Changing the Rear. Break loose your Lug Nuts Jack it Up Secure the Car with Good Jack Stands.Then finish remove tires,Besure To take the cap off your Masrer Cylinder and Take a Suction Bulb and Remove not Quite 1/2 of the Brake Fluid out of the Master So when you Push the Pistons Back in the Caliper you don't Get Brake Fluid Everywhere. Know you'll see your Calipers and Brake Pads. Remove Calipers.NOTE: Check your Calipers for Corrosion that Builds up over the Years on the Caliper piston. You'll need a C-Clamp To Push the Piston Back in the Caiper Flush with the Housing.You Need to Inspect your Rotors for Grooves If you have hit Metal to Metal From Pads to Rotor. I would Just Replace both Rear Rotors.Also while you have the Wheels Off, Inspect your Rear Bearings.If the are not showing Wear then Clen Them and Re-Pack with a Heavy Duty Wheel Bearing Grease & New Cotter Pins. NOTE: Your Rear Pads in Most cases for that Particular Vehicle Sometime the New Pads come with Rubber Shims,These will go on the Back side of your Inner Pads on Both Sides. Just Reverse the Removal Procedure And Your Good To Go.Don't For get to Check the Fluid Level in Your Master Cylinder.Top it off if Need. This Should get you Going.Please Let Me Know how my Solution helped you. Thank And Good Luck. From -d_hubbs

Remove the wheel, remove the 2 bolts holding on the caliper to the caliper carrier. You will need a large C-Clamp or a cailper piston tool. Place an old brake pad against the piston in the caliper and use the C-Clamp to push the brake pad against the piston to collapses the piston into the caliper. Also open the master cylinder cap and place a towel around the area to catch any brake fluid that would come out of the master cylinder as you collapes the piston, this is normal, but doesn't always happen, depending on the level of fluid in the master cylinder. Install the new pads and reinstall the caliper and wheel. Make sure you pump the brake pedal a few times before you take off, to get the pads against the rotor.

Raise and secure on stands after breaking loose the lug nuts and parking brake on for front pads.. Remove wheels and spread old pads back to push cylinders back in their bores on calibers to allow for thickness of new pads. Remove the 2 sliding claiber retaining bolts and rotate caliber out of mount and secure with wire, boungie cord, or rope to take weight of caliber brake hose. Remove old pads, install new, and reassemble in reverse order. Lugs on alloy wheel should be torgued to 95 foot lbs. Block front wheels, release parking brake,and do the back ones the same way. After completing, pump brake pedal slowly several times to seat new pads. If you move the MPV without pumping first, you will have no brakes to stop. If brake fluid level is high in master cylinder, you will need to take some out first to make room for returning fluid from caliber pistons being returned to their bores prior to any brake work. Rotors should be replaced or turned if scored or warped to have better clapping of pads to rotor surface.

You may have a leak in the booster or master cylinder. You can put a pressure tester on the system to test for leaks. It does sound like you have an air leak.
You can try to bleed the master cylinder, then slave cylinder, then brake lines.