1992 Factory Service Manual Brake Bleed Procedure

[Yellowoctupus]

BRAKE BLEEDING – MJ

A different rear brake bleeding procedure is required on MJ models.  This is necessary because of differential pressure valve internal circuitry and height sensing valve fluid line connection.

 

Essentially, the pressure differential valve inside the combo valve must be moved to a full forward position. This is necessary to allow complete bleeding of the combo valve, rear brake height sensing valve and both rear brake feed circuits. A manual bleeding procedure is preferred for MJ models.

 

Be sure to follow the MJ brake bleeding procedure carefully.  Incorrect brake bleeding will result in either a low pedal, or a low and spongy pedal

 

MJ BRAKE BLEEDING PROCEDURE

 

(1)    If master cylinder has been overhauled or a new cylinder will be installed, bleed cylinder on bench before installation. This shortens time needed to bleed system and ensures proper cylinder operation.

 

(2)    Fill master cylinder with Mopar or equivalent DOT 3 grade brake fluid.

 

(3)    Open all caliper and wheel cylinder bleed screws

 

(4)    Close bleed screws after fluid begins flowing from each screw.

 

(5)    Top off master cylinder reservoir again.

 

(6)    Apply parking brakes and shift transmission into Park, or Neutral, if equipped with manual transmission.

 

(7)    Open right front caliper bleed screw. This screw will remain open throughout rear brake bleeding procedure.

 

(8)    Position drain pan under right front caliper to catch brake fluid as it exits bleed screw.

 

(9)    Press brake pedal all way to floor and leave pedal in this position. This action will move pressure differential valve fully forward. 

 

(10)Start engine and observe red brake warning light. Light should remain on after engine is running. This indicates that differential valve is fully forward.

 

(11)Stop ending and full release parking brake. Do not close right front bleed screw yet. Screw must remain open until rear brake bleeding is completed.

 

(12)Observe flowing brake bleeding precautions:

·         Do not pump brake pedal at any time while bleeding. Air in system will be compressed into small bubbles that are distributed throughout hydraulic system. This will make a second and third bleeding operation necessary.

·         Bleed only one wheel brake unit at a time and use a bleed hose to bleed each wheel brake unit.

·         Attach one end of bleed hose to bleed screw and insert opposite end in glass container partially filled with brake fluid. Glass container makes it easier to see air bubbles as they exit the bleed hose.

·         Be sure end of bleed hose is immersed in fluid. Immersing hose end in fluid prevents air from being drawn back into cylinder and brake line.

 

(13)Bleed left rear wheel first and right wheel second. Have helper operate brake pedal while bleeding each wheel.

CAUTION: Do not allow the master cylinder reservoir to run out of fluid. An empty cylinder will allow additional air to be drawn into the system. Check fluid level frequently and add fluid as needed during bleeding operations.

 

(14)Bleed right front caliper first and left front driver side last.

 

(15)Refill master cylinder if necessary.

 

(16)Check brake operation before moving vehicle. Pedal should be firm, at normal height and not exhibit any sponginess.

[MiNi Beast]

Just what I needed to refresh my mind. Thanks for posting.