Brakes - Shudder/Vibration During Light to Moderate Stop
Article No.93-12-14
06/09/93
^ BRAKES - SHUDDER/VIBRATION DURING LIGHT TO MODERATE STOPS - SINGLE REAR WHEEL VEHICLES BUILT FROM 3/1/92 TO 2/18/93
^ VIBRATION OR SHUDDER DURING LIGHT TO MODERATE STOPS - SINGLE REAR WHEEL VEHICLES BUILT FROM 3/1/92 TO 2/18/93
LIGHT TRUCK:
1992-93 E-250, E-350, F-250, F-350
ISSUE:
A vibration or shudder may occur during light to moderate brake stops and snub (slight) brake applications between 20-55 mph (32-88 km/h). This may be caused by excessive wheel mounting pad height variability on 16x7 steel wheels which can contribute to brake drum distortion.
ACTION:
Replace all five (5) wheels with new wheels which have more consistent wheel mounting pad heights which do not distort the brake drums. Refer to the following procedure for service details.
1. Determine if the vibration/shudder is induced by the rear brakes, by making a light stop from about 35 to 50 mph (56 to 80 km/h) using the parking brake. To use the parking brake, proceed as follows:
^ F-Series: Hold the release handle out while depressing the parking brake pedal with the left foot.
^ Econoline: Depress the parking brake slightly and release causing the parking brake to set very lightly. Immediately, reapply the foot pressure on the parking brake pedal to activate the auto-release mechanism of the brake. The parking brake will then be capable of being modulated with light foot pressure to determine if the shudder is caused by the rear brakes.
2. If the vibration continues during the parking brake applications, perform the sequential steps as outlined in the Vibration/Shudder During Braking Chart.
WARNING:
OBSERVE ALL SAFETY AND WARNING STATEMENTS INCLUDED IN 1993 ECONOLINE, F-SERIES SERVICE MANUAL SECTION 04-04.
PART NUMBER PART NAME CLASS
F3UZ-1015-A Wheel 16X7 B
OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS:
Eligible Under Bumper To Bumper Warranty Coverage
OPERATION DESCRIPTION TIME
931214A Replace All Five (5) Wheel 3.3 Hrs.
Assemblies And Machine
Brake Drums - E250-350
Vehicles Built Between
3-1-92 And 2-12-93 With
Semi-Float Rear Axles /
F250-350 Vehicles Built
Between 3-1-92 And
2-18-93 Equipped With
Semi-Float Rear Axles
931214B Replace All Five (5) Wheel 4.0 Hr
Assemblies And Machine
Brake Drums - E250-350
Vehicles Built Between
3-1-92 And 2-12-93
Equipped With Full-Float
Rear Axles / F250-350
Vehicles Built Between
3-1-92 And 2-18-93
Equipped With Full-Float
Rear Axles
931214C Machine Brake Drums Only 0.9 Hr.
- E250-350 Vehicles Built
After 2-12-93 Equipped
With Semi-Float Rear Axles
/ F250-350 Vehicles Built
After 2-18-93 Equipped
With Semi-Float Rear Axles
931214D Machine Brake Drums Only 1.6 Hrs.
- E250-350 Vehicles Built
After 2-12-93 Equipped
With Full-Float Rear Axles
/ F250-350 Vehicles Built
After 2-18-93 Equipped with
Full-Float Rear Axles
DEALER CODING
BASIC PART NO. CONDITION CODE
1015 14
OASIS CODES:
301000, 306000, 703000, 703400