Front calipers fixed, now brakes dont work

SOURCE: rear brakes locking(until abs kicks in) with

Even if the proportioning valve is wide open the rear brakes should not lock up, this is indicative of the front piston not working on the master cylinder, if there was a problem with the abs it would throw a code so to check use two people to do this one to apply the brakes and one to tun the wheel. apply the brake gently while turning it by hand with all 4 wheels off the ground, if the wheels stop at the same time for all for wheels then you have another problem, Do this with the key on engine off in neutral. It sounds like you have a problem with the primary brake shoe the front of drum brake in rear or if disk then the disk brake. Check to see if the Emergency brake cables are not binding if the e-brake is disc the wire cable where the wheel splitter is may be frayed and is keeping the emergency brakes applied and causing this to happen. If this is not explained in a way you can understand post a reply and tell me to clarify if you don't understand what I am saying. The reason I say to do it without running is it will not use the ABS system to mess with your results this will test the mechanical area, thats where i think the problem is. If you let to much fluid drain out it is possible when you started bleeding the brakes if you did not bleed the fronts first you may have damaged the master cylinder piston seal for the disk brakes.

SOURCE: 1994 dodge 2500 diesel. Put

Hi,
sound as if you really do have a problem!
From your description I presume that you are confident in doing your own work?
The quickest way to check your system is to use brake hose clamps to isolate each section of the braking system. I would suggest that you rent or buy a set of the clamps.

Put the truck on axle stands and make sure it's safely secured. ]
If possible have an assistant to sit in the cab and depress the brake pedal on your instructions.
Place a brake hose clamp on both front brake hoses and the rear axle hose.
Depress the brake pedal firmly.
The pedal should have minimum movement, and be rock-solid and you should not be able to depress it further.
If the pedal does go down when you apply it, the likely reason is that the Brake Master Cyl is by-passing internally, ie, only one section is active.

You stated that the M/C had been replaced. so we shall presume that the brake pedal is rock hard.
Go to the rear brake hose clamp and release it. Instruct your assistant to depress the brake pedal. If the brake pedal moves a significant distance, then (a) your rear brake shoes require adjustment (b) rhere is a leaking brake cyl, (check for brake fluid in the drum) or (c) you have a "lazy' or a piston (s) which have siezed during a brake actuation. That problem will require removing the rear brake drums for further inspection. Not the problem? Then adjust the rear brakes if required, then depress the brake pedal again. The downward travel should now be noticeably reduced.

If all is well at the rear brakes. refit the brake hose clamp. Go to the passengers side front brake and have your assistant apply the footbrake. Pedal rockhard/minimun movement? Release the brake hose clamp whilst your assist has pressure on the pedal. spin the front wheel by hand, and note if (a) the brake pedal has excessive downward travel. (b) the brake pads are contacting the brake disc, (the wheel will cease rotating and you will hear the pads contact the disc.)

Pedal displays limited downward travel and pads contact disc? Refit the brake hose clamp and go to drivers side brake and follow the same procedure. If the pedal has excessive downward travel then you have found your inital problem.

If releasing both front brake hose clamps results in excessive brake pedal travel, then the problem will be easier to address if you deal with one side first, complete the resolution, test by using the brake hose clamps, then start / complete the other faulty brake.

Whichever side you start to work on, be methodical, boring as it sounds.
remove the road wheel, but before doing so, place a hand on the top and bottom of the tyre and rock the wheel away from you and check the bearing play. If memory serves me correctly, that year Dodge has the discs in one piece with the hub.

You have removed the wheel. Now, have your assistant turn the steering onto full right lock. Before continuing, I would like to remind you that the vehicle is up on axle stands and you have secured it safely, in order to conform with accepted safety parameters, correct?

The steering is now on full right lock and you can see both disc pads. Now, very carefully check the position of the caliper in relation to the disc pads. Is there and equal spacing on each side? Now, have your assistant release the brake pedal and very carefully observe the travel of the disc pad pistons. They should retract and the hub should turn freely by hand. A very light drag is allowed between disc pad and disc, but it should NOT be discernible when you rotate the hub by hand.

With no pressure on the brake pedal, and using an appropriate tool, attempt to have the caliper pistons retract into their cylinders / bores. Completed? Use caution as it is very easy to break / damage a disc by using undue force when retracting the pistons.

There is now an obvious gap between disc pads and disc (or rotor..sorry) Now, carefully check that the pad guide pins are not deformed and that the pads ride easily on them. if a pad jams when the brakes are applied, then, when the piston retracts, when force is removed from the brake pedal. There is an appreciable gap to close, upon the next application of the brakes!

Some types of disc pad retaining /guide pins are a tight fit, and it is very easy to tilt a pad when fitting the pins, causing the disc pad to fail to retract fully, and again, displayed by a brake pedal with excessive travel.

When the brake pedal is applied, the brake fluid has to fill the caliper piston bores, then exert pressure on the piston to force it against the disc pads, and they in turn are forced into contact with the disc. If the piston has to move an appreciable distance before contacting the disc pad, that takes more brake fluid to fill the bore of the piston, and the master cylinder piston has to travel further,resulting in a brake pedal that displays excessive travel .

I notice that you did not mention the type of effort or number of applications of the brake pedal which resulted in a firm pedal.

If you fitted replacement calipers, can I presume that you fitted new guide pins to the calipers?
Last but not least, (a) are they the correct calipers for the vehicle as regards piston bore size? The brake Master cyl will not be able to fill the bores of the calipers with enough fluid to drive the pistons out to apply the disc pads, if the bores are oversized. The pedal will also display excessive travel.
(b) If the brake master cyl is overfilled, when the brakes are applied, the master cyl will force fluid to the calipers, expand the caliper pistons, but will be unable to release the application to the pistons due to the fluid being unable to return to the master cyl as the allotted reservoir space has been filled with static fluid. When the brake pedal is depressed again, the Master cyl cannot service the caliper pistons on the first stroke as the pistons are locked at full stroke / travel in the bores, resulting in the brake pedal going to the floor, or giving that impression.
HOWEVER, that condition, if the vehicle is driven any distance, will result in the obvious odor of overheated disc brake pads, and the vehicle struggling to display any state of acceleration.
(c) Are they in fact the correct disc brake pads? It would be wise to remove a guide / retainer pin and check for free movement of the pad on the remaining pin. All ok, then refit the pin which you removed and test again. The pads have to be free to move on the pins, and thus align themselves with the face of the disc / rotor when the brakes are applied. Some people coat the pins with never-seeze or hi-temp grease when fitting them, others prefer them to be dry.

In closing, I would recommend that you check the full travel AND RETRACTION of the caliper pistons in their respective bores. It is not unknown for re-built / new parts to be defective.

It would be interesting to hear if any of the above proved to be beneficial in resolving your problem.

SOURCE: Problem with brake system on

A 2002 should not need a new master cylinder yet. If it is the rears grabbing, they probably installed something wrong, or they did not get all of the air out of the system which would be my best guess. A professional brake flushing machine is suppose to replace the old brake fluid with new while not letting air in. But tiny air bubble can form, and 3 days is just enough time for them to gather into larger air pockets, causing problems. Tell them you want all 4 corners manually bled before they start replacing any more parts, a step they should have done in the first place. If it is just the front brakes grabbing, the flush may have knocked dirt loose, messing with the front calipers. Either way, they will have to bleed the brakes after replacing them, at a cost to you and blame it on faulty parts. Long story short, I believe they cut corners when they flushed your truck, and are now looking for a way to blame it on parts.

SOURCE: drained break fluid and pedal

start from the rear driver side, and then the rear passenger side, and the front passenger side,and then the driver side make sure you keep plenty of fluid in the master cylinder during bleeding proccess

SOURCE: Have a 1993 dodge Caravan SE. Purchased it from a

IF YOUR BRAKE PEDAL HOLDS WHEN YOU PUMP BRAKES WITH ENGINE OFF.START ENGINE WITH FOOT ON THE BRAKE PEDAL.THE BRAKE PEDAL SHOULD DROP A LITTLE HOLD.IF BRAKE GOES TO FLOOR POWER. POWER BRAKE BOOSTER FAULTY.MAKE SURE POWER BRAKE BOOSTER IS GETTING VACUUM. IF POWER BRAKE BOOSTER OKAY. I SAY YOU HAVE PROBLEMS WITH THE BRAKE SYSTEM. VECHICLE SET UP FOR ABS BRAKE UNIT HAS TO BE REPLACE WITH ABS BRAKE UNIT.YOU CANT CHANGE A ABS BRAKE SYSTEM TO NON ABS BRAKE UNLESS YOU CHANGE MASTERCYLINDER TO THE NON ABS MASTERCYLINDER THE BRAKE LINES SET UP GOING HAVE TO BE CHANGED SAME AS THE NON ABS BRAKE SYSTEM, YOU NEED COMBINATION VALVE IT HAS METERING VALVE CONTROLS FRONT BRAKES AND PROPORTIONING VALVE CONTROLS REAR BRAKES, AND A BRAKE WARNING SWITCH ALSO BUILT IN THE COMBINATION VALVE. YOU NEED TO FIND SAME VECHICLE WITH NON ABS BRAKES LOOK AT BRAKE LINES ROUTING FROM MASTER CYLINDER TO COMBINATION VALVE TO FRONT AND REAR BRAKES. IT WOULD BEEN CHEAPER TO FIX THE ABS BRAKE UNIT THAN TRY TO DO CHANGE OVER BECAUSE ABS BRAKES SYSTEM SET UP DIFFERENT THAN NON ABS BRAKES SYSTEM THAT WHY YOU HAVING BRAKE PROBLEM.CHANGING ABS BRAKE SYSTEM TO NON ABS BRAKE SYSTEM WOULD BE LIKE TRYING TO PUT A 4 BARRELL CARBURETOR ON A CORVETTE WITH A 364 CU INCH ENGINE FUEL INJECTION ENGINE.