Rear brakes pistons not retracting

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,
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.

Remove brake fluid from the master cylinder brake fluid reservoir until the reservoir is approximately 1/2 full. Discard the removed fluid.

1. Raise and safely support the front of the vehicle. Remove the front wheels.
   

1. Remove or disconnect the following:
2. Front brake caliper guide pin bolts
   

• Brake caliper by slowly sliding it up and off the adapter and brake rotor. Support the caliper out of the way with a strong piece of wire. Do not let the caliper hang by the brake hose or damage to the brake hose will result.
  

1. If necessary, compress the caliper piston into the bore using a C-clamp. Insert a suitable piece of wood between the C-clamp and caliper piston to protect the piston.
2. Outboard disc brake pad from the caliper by prying the brake pad retaining clip over the raised area on the caliper. Slide the brake pad down and off the caliper.
   

• Inboard disc brake pad from the caliper by pulling the brake pad away from the caliper piston until the retaining clip on the pad is free from the caliper piston cavity
  

To install:

1. Be sure the caliper piston has been completely retracted into the piston bore of the caliper assembly. This is required when installing the brake caliper equipped with new brake pads.
   
2. If equipped, remove the protective paper from the noise suppression gaskets on the new disc brake pads.
   
3. Install or connect the following:
   
   • New inboard disc brake pad into the caliper piston by pressing the pad firmly into the cavity of the caliper piston. Be sure the new inboard brake pad is seated squarely against the face of the brake caliper piston.
     
   • Outboard disc brake pad by sliding it onto the caliper assembly
     
   • Brake caliper assembly over the brake rotor and onto the steering knuckle adapter
     
   • Caliper guide pin bolts and torque to: 35 ft. lbs. (47 Nm) on 2002–04 models or 26 ft. lbs. (35 Nm) on 2005 models
     
   • Front. Apply the brake pedal several times until a firm pedal is obtained.
     
4. Check the fluid level in the master cylinder and add fluid as necessary. Road-test the vehicle.
   

For the rotors:

1. Remove brake fluid from the master cylinder brake fluid reservoir until the reservoir is approximately 1/2 full. Discard the removed fluid.
   
2. Raise and safely support the front of the vehicle. Remove the front wheels.
   

1. Remove or disconnect the following:
2. Front brake caliper guide pin bolts
   

• Brake caliper by slowly sliding it up and off the adapter and brake rotor. Support the caliper out of the way with a strong piece of wire. Do not let the caliper hang by the brake hose or damage to the brake hose will result.
  

1. If necessary, compress the caliper piston into the bore using a C-clamp. Insert a suitable piece of wood between the C-clamp and caliper piston to protect the piston.
2. Outboard disc brake pad from the caliper by prying the brake pad retaining clip over the raised area on the caliper. Slide the brake pad down and off the caliper.
   

• Inboard disc brake pad from the caliper by pulling the brake pad away from the caliper piston until the retaining clip on the pad is free from the caliper piston cavity
  

To install:

1. Be sure the caliper piston has been completely retracted into the piston bore of the caliper assembly. This is required when installing the brake caliper equipped with new brake pads.
   
2. If equipped, remove the protective paper from the noise suppression gaskets on the new disc brake pads.
   
3. Install or connect the following:
   
   • New inboard disc brake pad into the caliper piston by pressing the pad firmly into the cavity of the caliper piston. Be sure the new inboard brake pad is seated squarely against the face of the brake caliper piston.
     
   • Outboard disc brake pad by sliding it onto the caliper assembly
     
   • Brake caliper assembly over the brake rotor and onto the steering knuckle adapter
     
   • Caliper guide pin bolts and torque to: 35 ft. lbs. (47 Nm) on 2002–04 models or 26 ft. lbs. (35 Nm) on 2005 models
     
   • Front. Apply the brake pedal several times until a firm pedal is obtained.
     
4. Check the fluid level in the master cylinder and add fluid as necessary. Road-test the vehicle.
   

you need a special tool avalable at most parts stores. its a disc brake piston turning tool. you have to rotate piston clockwise while pushing in on piston. you can fabricate something that enguages the slots and push and turn till all the way in.make sure to note position of slots and put them in same place as was before or the pin on the pads wont enguage the slot

dont worrie about the e brake adjustment prie on the caliper to remove from caliper braket just get the tool to return the piston inside to caliper if looks like this you have to press in or if is a cross turn clock wise to push in

One side,turns right,and push in slightly,and the other side turns left,to retract.

no that is only the older rear calipers on gm and others. the fronts do not have that style caliper and sound like the calipers are frozen and may be way your changing the pads. try opening the bleeder screw and then compressing them if they go then you need need brake hoses and if not you need calipers. god luck man

it has front and rear disc brakes, disc brakes are very simple to change out. Most disc brakes have two bolts that hold them on, one on the bottom one on the top on the inside of the brake caliper, they may be an allen head, or just a bolt. Remove them counter-clockwise. After you remove the two bolts, lift up and away on the caliper and the whole assembly will come off. Once you pull the assembly off you will see the two pads, one of them is driven by a piston, the other one is fixed. Remove the fixed one, they just pop off (have little metal clips you may have to slide the pad off). Take a C-clamp or something comparable to squeeze with, place it on the back of the caliper and on the old pad thereby squeezing the cylinder back into the piston, once you squeeze the cylinder back into the piston, it will give you room needed for thicker new brake pads. Piston should retract with the c-clamp fairly easy, shouldn't be a whole lot of resistance. Remove c-clamp after you get it to retract and remove old pad. Put new pad on, just like you took the old ones off. All four are basically the same to change out, they all have two bolts holding them on. You pull those, get the pistons to retract and replace the worn pads, put them back on, line up holes, put bolts back in... and your good to go. When you get back in the car and turn the key on, you may have to pump the brakes a few times.

The hard part is pressing the caliper piston abck into the caliper so you can get the new, thicker pads over the rotor. A large C Clamp works best.

SECTION 206-03: Front Disc Brake 2001 Villager Workshop Manual
REMOVAL AND INSTALLATION Pads —Front Disc Brake Removal

1. Remove the wheel and tire assembly. For additional information, refer to Section 204-04 .

1. Remove the front disc brake caliper bolts. torx bit. T20?

1. Support the front disc brake caliper from the front strut and spring assembly using mechanics wire.

1. Remove the front disc brake pads.
   1. Remove the outboard front disc brake pad.
   1. Remove the inboard front disc brake pad.

Installation

1. CAUTION: Make sure the master cylinder reservoir does not overfill and spill brake fluid while retracting the front disc brake caliper piston.
   NOTE: It is necessary to fully retract the front disc brake caliper piston in the bore before installing the front disc brake pads.
   Install the front disc brake pads.
   1. Install the inboard front disc brake pad.
   1. Install the outboard front disc brake pad.

Caution. The outer pads are left and right. put left on driver side.

1. Position the front disc brake caliper on the front-wheel knuckle and install the brake caliper pin bolts.

1. WARNING: It is necessary to depress the brake pedal several times to position the front disc brake caliper piston before driving the vehicle.
   

you must spread the pads out....do this with a wedge-shaped tool and use lever action to push the caliper pistons back to the fully-retracted positions in the cylinders. The pistons are currently in the position where the last pads had allowed them to extend to. It is good practice to (excercise) the pistons at pad change time by moving the pistons back and forth slowly to remove any oxidation at the cylinder walls, but never allow pistons to fully extend...prevent this by using a piece of wood to act as the thickness of one rotor and 2 pads. You extend the pistons by using the car's brake pedal, then retract them with the wedge.