BRACKET AS 1559830 - Caterpillar

Introduction
If a machine does not travel straight, determine whether the problem occurs at full travel speed (travel control lever at the maximum position) or at partial travel (travel control lever at mid-position). If the machine will not travel straight at full travel lever position, the cause is usually unequal pump flow. If the machine does not travel straight at partial travel lever position but will at full travel lever position, the travel control valves are not opening uniformly. 1. Check machine for travel drift.Reference: Refer to, "Operational Tests, Travel On Level Ground" Form SENR6187 for additional information. Expected Result:Travel drift should be within the service limits of 1500 mm (59.1 in) in 20 m (22 yds) under all test conditions. Results:* OK - STOP.* FULL PEDAL DRIFT - Proceed to Step 2.* PARTIAL PEDAL DRIFT - Proceed to Step 3.* DRIFT WITH IMPLEMENT - Proceed to Step 4.* HIGH LOAD DRIFT - Proceed to Step 5.2. Perform Travel Drift At Full Pedal. For further information refer to the section, "Travel Drift At Full Pedal". Results:* REPAIRED, OK - STOP.* OK - Cause for problem not found with this test. The test equipment may be faulty, a repair may have been made incorrectly, or an error may have been made during the diagnosis of this problem. Check to determine whether or not the problem is still present. If it is, repeat test procedure. STOP.3. Perform Travel Drift At Partial Pedal. For further information refer to the section, "Travel Drift At Partial Pedal". Results:* REPAIRED, OK - STOP.* OK - Cause for problem not found with this test. The test equipment may be faulty, a repair may have been made incorrectly, or an error may have been made during the diagnosis of this problem. Check to determine whether or not the problem is still present. If it is, repeat test procedure. STOP.4. Check for travel drift when operating an implement while traveling.Reference: Refer to, "Operational Tests, Straight Travel Tests" Form SENR6187 for additional information. Expected Result:Machine continues to travel straight when travel and an implement are used at the same time. Results:* OK - Cause for problem not found with this test. The test equipment may be faulty, a repair may have been made incorrectly, or an error may have been made during the diagnosis of this problem. Check to determine whether or not the problem is still present. If it is, repeat test procedure. STOP.* NOT OK - Check straight travel control valve in the main control valve for sticking and not shifting. If the straight travel control valve is sticking, it may be possible to salvage the valve by polishing the spool with fine emery. If salvage is not possible, replace only the basic control valve group which contains the straight travel control valve. STOP.5. Check pump regulation as a cause for travel drifting while traveling at a high load.a. Place the travel speed selector in LOW (tortoise) position. (Testing travel at high speed could involve the motors