2888351 - F01 POOR BRAKING ACTION

As the pressure exerted on the brake pedal increases, the braking action does not correspond.
Results of the tests
1CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Connect the diagnostic equipment (Examiner or other instruments) to the diagnostic socketCheck that there are no faults in the ABS control unit.Continue to Step 2An error is detected in the control unitContinue according to the instructions for the diagnostic equipment
Lack of dialogue with the control unit

Restore:

  • the connection between the ABS control unit and the diagnostic connector
  • the ABS control unit supply
See   E7020  ABS
2ACTIVE DIAGNOSIS WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation

Using the diagnostic equipment (Examiner or other instruments) carry out the active diagnosis of:

  • pump motor
  • solenoids
Continue to Step 3Fault detected in one solenoidReplace electrohydraulic unit-electronic control unit Op.   3340A12 
3CHECK FRICTION SURFACESAll OKProblems metOperation

Check:

  • condition of front pad friction surfaces
  • condition of rear pad friction surfaces
Continue to Step 4Friction surfaces vitrified or with traces of grease, oil or waterClean, check and eliminate the causes of the fault
Front brake pads damaged or wrong typeReplace pads Op.   3310A60 
Rear shoes damaged or wrong typeReplace the shoes Op. 3320B10
4CHECK FRONT DISCS AND CALIPERSAll OKProblems metOperation
Check condition of front brake discsCheck the condition of the brake caliper pistonsContinue to Step 5Front discs worn or damagedGrind the discs Op.   3310A54  , or replace if necessary
Front caliper pistons worn or seizedReplace brake calipers Op.   3310A30 
5CHECK REAR DRUMSAll OKProblems metOperation
Check the condtion of the rear brake drums.Check the condition of the rear brake cylinders.Continue to Step 6Rear drums worn or damagedReplace the drums Op.   3320B30 
Shoe control cylinders worn or seizedReplace the cylinders Op.   3320B20 
6CHECK VACUUM PIPEAll OKProblems metOperation
Check condition and fitting of vacuum pipeContinue to Step 7Pipe fitted incorrectly or bentRefit correctly
Pipe damagedReplace the vacuum pipe Op.   3330D24 
7CHECK NON-RETURN VALVEAll OKProblems metOperation
Check that the non-return valve is working properlyContinue to Step 8Non-return valve not working properlyReplace non-return valve Op.   3330D20 
8CHECK BRAKE SERVOAll OKProblems metOperation
Check that brake servo is working properly: See Test   3330DA  Check operation of brake servo Continue to Step 9Brake servo not working properlyReplace the servo unit Op.   3330D10 
9CHECK ENGINE VACUUMAll OKProblems metOperation
1.9 JTD 8V ABSCheck vacuum in vacuum circuit:Continue to Step 10Vacuum value incorrectReplace brake servo vacuum unit Op.   3330D30 
1.6 16v ABSContinue to Step 10
10CHECK BRAKE PIPES/HOSES AND BLEEDINGAll OKProblems metOperation
Visually check that there are no kinks or restrictions in the brake pipes, bleed the system Op.   3330A18  and check that fluid emerges from the bleed screws as normalContinue to Step 11There are kinks or restrictions, fluid does not come out normallyReplace the section of pipe affected by the fault (see Assembly 3340B)
11CHECKING CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisFault persistsSearch for the fault starting from another symptom'
As the pressure exerted on the brake pedal increases, the braking action does not correspond.
Results of the tests
1CHECK FRICTION SURFACESAll OKProblems metOperation

Check:

  • condition of front pad friction surfaces
  • condition of rear pad friction surfaces
Continue to Step 2Friction surfaces vitrified or with traces of grease, oil or waterClean, check and eliminate the causes of the fault
Front brake pads damaged or wrong typeReplace pads Op.   3310A60 
Rear shoes damaged or wrong typeReplace the shoes Op. 3320B10
2CHECK FRONT DISCS AND CALIPERSAll OKProblems metOperation
Check condition of front brake discsCheck the condition of the brake caliper pistonsContinue to Step 3Front discs worn or damagedGrind the discs Op.   3310A54  , or replace if necessary
Front caliper pistons worn or seizedReplace brake calipers Op.   3310A30 
3CHECK REAR DRUMSAll OKProblems metOperation
Check the condtion of the rear brake drums.Check the condition of the rear brake cylinders.Continue to Step 4Rear drums worn or damagedReplace the drums Op.   3320B30 
Shoe control cylinders worn or seizedReplace the cylinders Op.   3320B20 
4CHECK VACUUM PIPEAll OKProblems metOperation
Check condition and fitting of vacuum pipeContinue to Step 5Pipe fitted incorrectly or bentRefit correctly
Pipe damagedReplace the vacuum pipe Op.   3330D24 
5CHECK NON-RETURN VALVEAll OKProblems metOperation
Check that the non-return valve is working properlyContinue to Step 6Non-return valve not working properlyReplace non-return valve Op.   3330D20 
6CHECK BRAKE SERVOAll OKProblems metOperation
Check that brake servo is working properly: See Test   3330DA  Check operation of brake servo Continue to Step 7Brake servo not working properlyReplace the servo unit Op.   3330D10 
7CHECK ENGINE VACUUMAll OKProblems metOperation
1.9 JTD 8V [[]Check vacuum in vacuum circuit:Continue to Step 8Vacuum value incorrectReplace brake servo vacuum unit Op.   3330D30 
1.6 16v [[]Continue to Step 8
8CHECK BRAKE PIPES/HOSES AND BLEEDINGAll OKProblems metOperation
Visually check that there are no kinks or restrictions in the brake pipes, bleed the system Op.   3330A18  and check that fluid emerges from the bleed screws as normalContinue to Step 9There are kinks or restrictions, fluid does not come out normallyReplace the section of pipe which is faulty (see Assembly 3330E)
9CHECKING CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisFault persistsSearch for the fault starting from another symptom'