Measure brake pedal height, travel, and free play (as applicable); determine necessary action.
Given the proper specifications for brake pedal height by the Instructor, the student will be able to properly measure pedal height, travel, and free play (as applicable), determine necessary action, and diagnose problems related to measurements that are out of specification with 100% accuracy.
Common Core Technical Standards:
New Common Core State Standards:
RST 11-12 3
RST 11-12 2
Teacher Designed Materials and Other Handouts
Specification sheet or manual for the automobile being used, which states proper pedal height distance from the floor. Tape measure or yardstick for making measurements. Pliers can be used to adjust pushrod in or out as needed.
1. Give students a specification sheet from a shop manual or database stating the correct pedal height measurement for the automobile that is provided. Typical heights range from 6 to 7 inches.
2. Demonstrate to the students the proper way to measure the pedal height. On some cars this is done by measuring from the floor to the pedal; on others it is done by measuring from the steering wheel to the brake pedal. Some are taken from a special point below the floor mat. When measuring, be sure to instruct students to loosen the brake switch locknut and back off the brake switch so it no longer touches the pedal. When finished, instruct students to adjust the brake switch as required. If it is not adjusted correctly, stop lamps and cruise control can be affected.
3. Instruct students on reasons why pedal height may be out of specifications. Causes can be as follows: a. Worn Pedal Bushing b. Weak Return Spring c. Maladjusted Master Cylinder Push Rod
4. It is also important to note the adjustment for pedal free play, which is the amount of movement before the beginning of brake application. It is needed to prevent brake drag. This can also be caused by a misadjusted master cylinder push rod. A bad return spring and a worn pedal bushing can also create this problem. Pedal free play is usually between 1/16 of an inch to 3/16 of an inch. To measure, push pedal down by hand until you feel an increase in effort. Use a ruler to measure this distance.
Students can practice this task by using the specification sheet provided to measure the pedal height according to manufacturer's specifications. Students should write down measurements and compare to proper measurements. If a problem exists, the students should check the condition of the bushing, spring and push rod to see if any of these may be the cause of the problem.
Evaluation and feedback Prior to Testing or Lab Work
Objective 1/ Formative assessment / Instructor will observe students as they practice the procedure to assure correct procedure and safety practices are being followed. A checklist should be utilized to chart student progress on the task. Questioning techniques will be utilized as necessary to demonstrate student comprehension / Adaptations and/or accommodations for special needs students will be added if required.
STUDENT ASSESSMENT: (Assess student progress with performance criteria.)
Objective 1/ Summative assessment / written test questions on stated objective / adaptation and / or accommodations for special needs students will be added if required
IMPACT--Reflection/Analysis of Teaching and Learning: (How did students’ progress in relation to the state objectives? Was the instruction successful? Analyze samples of student work particularly that which is unsatisfactory, for the purpose of planning further instruction.)
REFINEMENT--Lesson Extension and Follow-up: (To be filled in as the lesson is modified during initial planning and/or during the teaching learning process.)