Mazda lantis 1994.how can I get the brake piston pushed back. I used a G clamp and undid the bleeding nipple but it wont move.

Hi, it might be fluid stopping it, put a clamp on flexible pipe to stop air going back up pipe, undo bleed nipple and try CAREFULLY, to push back in to caliper. Some pistons turn on way out as they wear, ( god knows why) so try turning piston clockwise OR anticlock wise as you push piston in, it depends which side you are working on.
And, it might be the "o" ring stuck out of caliper bore, be VERRY carful not to damage this, you might have already done this....
if you succeed, remove clamp & bleed. Good luck.

you need a C clamp open the C clamp up and place the C clamp to the back side of the calaber and the plunger side of calaber then jjust turn the C clamp till you see its all way open then you replace your breaks

You dont say what vehicle this is, start by gently pressing the brake pedal and see if the piston moves outward at all, dont push to far for obviouse reasons, check for obviouse signs of corrosion which may be causing your problem, you may need to use 2 large pair of grips one on the piston from the top and one from the bottom, some pistons are almost an interfearance fit and have to be pushed home square, check the brake fluid res is not overfull this will prevent piston movment, make sure lid is removed, also now grip the brake hose with a pipe clamp or a pair of grips carefully, undo the bleed nipple and try pusshing home the piston the fluid will escape momentarily from the open nipple, if the piston closes, close bleed nipple imediatly, if this has allowed the piston to be pushed home it maybe the rubber brake hose has collapsed an will need replacing, this is normaly associated by the vehicle pulling to one side while breaking, good luck, at the worst a replacment calliper maybe the best way forward

yes, you can rent one from Auto Zone, Advanced Auto Parts, etc.

just use a normal C-clamp to compress it - and some wood between the clamp and caliper so you don't scratch the caliper, undo the bleed nipple a little if it wont squash together.

Open the bleed nipple while the caliper is tight in the clamp - open it till it weeps and tighten the clamp till the pistons are flat with the caliper then tighten the bleed nipple. you should be able to fit the brakes now easily. Remember to check and if necessary replenish the brake fluid reservoir.

don't need any special tools, standard sockets sets, "C" clams is a must unless your a He-Man and wrench set, plyer or needle nose will do. I assumed being 2003 your rotor never have been turn and i recommend every time you change your bakes is good idea to have your rotor turn. reason is it will make your pad last lot longer, removed any vibration and better even wear on the pad and eliminate any squealing although is not necessary to do so. make sure you get extra break fluid to bleed the brakes. get your self 5 feet long smallest vacum rubber hoses and a glass jar to bleed your brake fluid in. the rubber vacum hose you going to use to fit on to the bleeding nipple and run the other end of line to your the glass jar to save the brake fluid when you bleed the brakes. when removing caliper, check inspect make sure the rubber seals around your piston look good and not crack or deteriorated. before applying new pad make sure you open the bleed valve to reduce the pressure by turning the bleed nipple counter clockwise and leave it open attach that rubber hoses to the nipple because you going to press on the piston back into it housing with the "C" clamp in order for new pad to fit. becareful not to damage the rubber seals around the piston. its going to take lots of effort to push that piston back in so be a bare with it if needs to. once the pad is back in make sure you keep the reservoir full with brake fluid and then bleed the brake. two people is a good idea to do brake. one will do the pumping the brake and holding it down and other will bleed the nipple. I bleed it 2-3 time will do the job. good luck!

HELLO. YOU NEED TO USE A (C) CLAMP.!!! TO COMPRESS THE CALABER PISTION'.BACK. THAT . WAY YOU WON'T NEED TO BLEED YOUR BREAK'S . HOPE THIS HELP'S YOU GOOD LUCK

No but thier is an important step to take while doing brakes so that back pressure does not upset or contaminate the ABS.Make sure you clamp the flexible brake hose with a hose line clamp that will not damage hose.Loosen the bleed nipple just enough so that the pressure from the piston being pushed back forces the fluid out.You will notice the color of the fluid is different compared to whats in the master cylinder.Heat destroys whats in and around the brake piston and better to be rid of it than letting it stay in the lines.Once piston is all the way back assemble brake system,undo clamp and bleed as normal,If done right there will be very little air and no brake issues in regard to the ABS.Good luck

You have to clamp the flexible break hose with the appropriate tool that will not damage hose so that no pressure can go back up the break line when then piston is wound back.You crack the bleed nipple just enough that it only flows out when the pressure from the piston being wound back in pushes it out.Once piston is all the way back in retighten the bleed nipple,reassemble caliper etc and bleed.The reason you vent off fluid this way is not to put back pressure on the ABS,Bleeding the brakes is easier and the worst of the fluid(most stressed)is evacuated from the brake lines.Last thing top up the master cylinder with exactly the same fluid that is in the vehicle.Mixing fluids can be hazardous in respect of the ABS and seals throughout the brake system.When winding your pistons take special care as the pistons wind back in in opposite directions.