TM 5-3805-260-24The setting of the relief valve for maximum pressuremust be according to the Service Manual.CAUTION: When the pressures are higher than 1000psi, slowly open the manual load valve before turningthe steering wheel back to center. This will preventpossible damage to the pressure gauge.Test 2: System Oil Temperature1. Open the manual load valve fully.2. Turn the steering wheel to the RIGHT TURNposition.3. Write down the oil temperature.Test 3: System Base Flow Rate1. Open the manual load valve fully.2. Turn the steering wheel to the RIGHT TURNposition.3. Run the engine at test rpm.4. Check pressure to make sure it is at a minimumvalve of approximately 100 psi.5. Write down the flow rate (gpm). The base flowrate of the system will be the same as the low pressureflow of the hydraulic pump. Because there will beminimum leakage in the control valves, lines andcylinder packings at 100 psi, the base flow rate can beused to find the flow differential in Tests 4 and 5.NOTE: If the base flow rate (Test 3) is less than the flowrate in Test 4, do Test 4 first and then Test 3. For vanepumps only, this takes place when the vanes in thepump do not have full extension at low pressure.Tests 4 and 5: Leakage RatesThese two tests are similar. Each test is done asfollows:1. Move the steering wheel to the respective TURNpositions.2. Run the engine at test rpm.3. Make an adjustment to the manual load valve toget 1000 psi pressure.4. Make the system constant with these conditions.5. Write down the flow rate (gpm) for each test. Theflow differential for each test (4 and 5) is found by takingthe flow rate for each test away from the base flow rate(Test 3). The percent of flow loss for each test (4 and 5)is found by dividing the flow differential for each test bythe base flow rate (Test 3).Test 10: System Oil Temperature1. Open the manual load valve fully.2. Turn the steering wheel to the RIGHT TURNposition.3. Write down the oil temperature.Make a comparison of the oil temperature from Tests 2and 10. Test 2 must be 150 5F and Test 10 must beinside of (within) 10F of Test 2. For each 10 F higherdifference (Test 10 higher than Test 2), take away .5gallon per pump cartridge from the leakage rate. Foreach 10F lower difference, add .5 gallon per pumpcartridge to the leakage rate.Is It Necessary To Make More Tests?If so, Which Circuit(s)?Make a comparison of the test data with the data onChart A for the specific machine under test. The percentof flow loss on Chart A is maximum for bestperformance.Components that are worn, or not working correctly, arefound by their flow differential and percent of flow loss orlower system efficiency. System values for new andrebuilt machines must not be more than the percent offlow loss in the system tests shown on Chart A for thespecific machine. The permissible flow differential is afunction of machine application. For applications withlow travel speeds, the permissible flow differential canbe more than for applications with high travel speeds.If the percent of flow loss is acceptable, the Tee Test iscompleted.If the percent of flow loss is not acceptable, the tests forthe pump and/or the blocked cylinders must be done.TroubleshootingThe following examples are a list of problems andprobable reasons. They will aid in finding the2-119
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business