1994 MAZDA MX-5 low oil pressure

K OUTLINE FLUID PASSAGE LOCATIONS Transmission Case TO SECOND SERVO RELEASE SlDE TO DIRECT CLUTCH AND FOURTH GEAR SERVO RELEASE SlDE TO SECOND SERVO APPLY SI OIL PUMP DISCHARGE TORQUE CONVERTER PRESSURE TO REAR CLUTCH TO FRONT CLUTC OIL PUMP SUCTION , REAR LUBRICATION TO LOW AND REVERSE BRAKE OIL PUMP SUCTION TO FRONT CLUTCH TO DIRECT CLUTCH AND FOURTH GEAR SERVO RELEASE SlDE TO REAR CLUTCH / OIL PUMP DISCHARGE TORQUE CONVERTER PRESSURE Oil Pump OIL PUMP DISCHARGE FRONT LOCKUP CONTROL OIL PUMP SUCTION SOLENOID VALVE TORQUE CONVERTER PRESSURE 0i PUMP DISCHARGE Gartner Banana

TROUBLESHOOTING If the 3 steps on page K-8 are followed, the cause of the problem should be located. Another guide to faster location of the causes of problems, the QUICK DIAGNOSIS CHART, is on page K-1 0. b In this chart, numbers are used to indicate the components that may be the cause of 22 possible prob- lems. It is necessary to check only those components indicated by numbers during each step of the trouble- shooting process to locate the cause of the problem quickly. QUICK DIAGNOSIS CHART The QUICK DIAGNOSIS CHART shows different .problems and the relationship of components that might be the cause. 1. Components indicated in the "Adjustment" row indicate the possibility that the problem may result from an incorrect adjustment. Check the adjustment of each component, and readjust if necessary. 2. Components indicated in the "Self-DiagnosisWrow are diagnosed by the Powertrain control module (Transmission) self-diagnostic function. 3. Input and output signals of the Powertrain control module (Transmission) for components indicated in the "Tester" row can be easily checked with the Engine signal Monitor. 4. Components indicated in the "Mechanical System Test" row can be checked for malfunction by the re- sults of oil pressure test. 5. Components indicated in the "Road Test" row can be checked for malfunction by the results of the road test. 6. The numbers in the chart indicate the order of inspection for detecting malfunctions. 7. Circled numbers indicate that the transmission must be removed from the vehicle. 8. The checking, adjusting, repair, and replacement procedures for components are described in the page(s) shown in the "Reference page" row. Gartner Banana

K MECHANICAL SYSTEM TEST Evaluation of Stall Test 4bove specification Nithin specification In all ranges In D (Normal), and L ranges In D (Normal) range only In R range only 3elow specification Possible cause I Worn oil Dumo Oil leakage from oil pump, control Insufficient line pressure Direct clutch and overdrive one-way clutch sli~~ina Rear clutch slipping One-way clutch slipping Low and reverse brake slipping Front clutch slipping Perform road test to determine if this is caused by low and reverse brake or front clutch as follows: a) Effective engine braking in L range . . . . . . . . . . Front clutch b) No enaine brakina in L range . . . . . Low and reverse brake All ~hiftcont~elements within transmission are functioning normally Engine out of tune One-wav clutch sli~~ina within toraue converter Gartner Banana

K MECHANICAL SYSTEM TEST LINE PRESSURE TEST This test measures line pressures for checking the hydraulic components and inspecting for oil leakage. Preparation d 1. Perform the preparation procedure shown in the STALL TEST. (Refer to page K-22.) 2. Connect a tachometer to the engine. Warning Removing the square-head plug when the ATF is hot is dangerous. Hot ATF can come out of the opening and badly burn. Before removing the square-head plug, allow the ATF to cool. 3. Connect the SST to the line pressure inspection hole(s). Procedure 1. Start the engine and check the idle speed in P range. (Refer to section F.) Idle speed: 750--850 rpm * 2. Shift the selector lever to D range and read the line pressure at idle. Caution If the accelerator pedal is pressed for longer than 5 seconds while the brake pedal is pressed, the transmission could be damaged. Therefore, do steps 3 and 4 within 5 seconds of each oth- er. 3. Depress the brake pedal firmly with the left foot and gradually depress the accelerator pedal with the right foot. 4. Read the line pressure as soon as the engine speed becomes constant, then release the accelerator .- pedal. 5. Shift the selector to N and let the engine idle for 1 minute or more to cool the ATF. 6. Read the line pressure at idle and at the engine stall speed for each range in the same manner. Gartner Banana

MECHANICAL SYSTEM TEST K Specified line pressure: 7. Cool the transmission and reconnect the SST to the line pressure inspection hole. 8. Connect a vacuum pump to the vacuum diaphragm and place the pump inside the vehicle. 9. Shift the selector lever to R range. 10. Read the line pressure at idle as described below. Range D range S range L range R range Specified line pressure: Pressure kPa {kgflcm2, psi] Idle 285--362 i2.9-3.7,42-52) 785--921 (8.G9.4, 11 4--133) 295-392 {3.0-4.0,43--56) 775--970 (7.9--9.9, 1 1 S140) Vacuum Atmospheric pressure 1 400 mmHg (15.7 inHg} I 393490 (4.0-5.0,57-71) I Stall 79S912 18.1-9.3, 11 &I321 795--91 2 {8.1-9.3, 11 6--132) 883-1,078 l9.0-11 .O, 128-1 56) 1,972-2,167 (20.1-22.1,286--314) Line pressure kPa {kgf/cm2, psi) 883-1,078 {9.&11 .O, 128--156) 200 mmHg (7.87 inHg) - Evaluation of Line Pressure Test 687-784 17.0-4.0, 10-113) Below specification I Excessive line pressure Condition I Possible Cause In all ranges Worn oil pump Fluid leakage from the oil pump, control valve body, and/or transmission case Stuck pressure regulator valve Fluid leakage from the direct clutch and/or fourth gear band servo release side hydraulic circuit In D (Normal), S (Normal), and L Fluid leakage from the rear clutch hydraulic circuit ranaes I Stuck pressure modifier valve In S (Normal & Hold) and L ranges I Fluid leakage from the throttle backup valve hydraulic circuit In L and R ranges I Fluid leakage from the low and reverse hydraulic circuit In S range (Hold) In R range only Stuck throttle backup valve Stuck backup control valve Backup control function (electronic) not operating properly Stuck pressure modifier valve Stuck backup control valve Fluid leakage from the front clutch and/or 2nd band servo release side hydraulic circuit Below specification Excessive pressure In all ranges Same as Line Pressure Test Leaking or disconnected vacuum hose Leaking vacuum diaphragm Diaphragm rod too long Stuck vacuum throttle valve Stuck Dressure renulator valve I In S ranae (Hold) I Stuck pressure modifier valve Gartner Banana

WIRE DIAMETER Disassembly note Snap ring Caution Depress the spring retainer only enough to re- d move the snap ring. Overpressing will damage the retainer assembly edges. 1. Compress the spring by using the SST, then remove the snap ring with snap ring pliers. 2. Remove the SST. 3. Remove the spring retainer and spring. Clutch piston 1. Install the direct clutch drum onto the drum support along with the seal rings. 2. Remove the piston by applying compressed air through the oil passage. Air pressure: 392 kPa {4.0 kglcm2, 57 psi) max. Inspection Drive plate 1. Measure the facing thickness in three places, and deter- mine the average of the three readings. Standard thickness: 1.6mm (0.063 in) Minimum thickness: 1.4mm (0.055 in) 2. If not within specification, replace the drive plates. Return spring 1. Measure the spring specifications. Specifications 2. If not within specification, replace the return spring. Clutch piston 1. Verify that there is no air leakage when applying com- pressed air through the oil hole opposite the return spring. 2. Verify that there is airflow when applying compressed air through the oil hole on the return spring side. - Outer dia mm {in) 8.0 (0.315) Air pressure: 392 kPa (4.0 kg/cm2, 57 psi) max. No. ,oils 14.5 - Free length mm {in) 30.5 {1.201} 3. If not correct, replace the clutch piston. Wire dia. rnm {in) 1.3 (0.051) Gartner Banana

K TRANSMISSION -&- WIRE DIAMETER Disassembly note Snap ring Caution 4' Depress the spring retainer only enough to install the snap ring. Overpressing will damage the re- tainer assembly edges. 1. Compress the spring by using the SST, then remove the snap ring with snap ring pliers. 2. Remove the spring retainer and spring. Clutch piston 1. Install the front clutch drum onto the drum support along with the seal rings. 2. Remove the piston by applying compressed air through the oil passage. Air pressure: 392 kPa (4.0 kg/cm2, 57 psi) max. Inspection Drive plate 1. Measure the facing thickness in three places, and deter- mine the average of the three readings. Standard thickness: 1.6mm (0,063 in) Minimum thickness: 1.4mm (0.055 in) 2. If not within specification, replace the drive plates. Return spring 1. Measure the spring specifications. Specifications I Outer dia. I Free length I No. of coils I mm {in} mm {in} Wire mm {in) dia. I Air pressure: 392 kPa (4.0 kg/cm2, 57 psi) max. 2. If not within specification, replace the return spring. Clutch piston 1. Verify that there is no air leakage when applying com- pressed air through the oil hole opposite the return spring. 2. Verify that there is airflow when applying compressed air through the oil hole on the return spring side. 3. If not correct, replace the clutch piston. Gartner Banana

TRANSMISSION K WIRE DIAMETER Disassembly note Snap ring Caution Depress the spring retainer only enough to re- move the snap ring. Overpressing will damage the retainer assembly edges. 1. Compress the spring by using the SST, and remove the snap ring with snap ring pliers. 2. Remove the spring retainer and spring. Clutch piston 1. Install the rear clutch drum onto the drum support along with seal rings. 2. Remove the piston by applying compressed air through the oil passage. Air pressure: 392 kPa (4.0 kg/cm2, 57 psi) max. Inspection Drive plate 1. Measure the facing thickness in three places and deter- mine the average of the three readings. Standard thickness: 1.6mm (0.063 in) Minimum thickness: 1.4mm (0.055 in) 2. If not within specification, replace the drive plates. Return spring 1. Measure the spring specifications. I Outer dia. I Free length I No. of I ;i;;i I mm fin) mm {in} 2. If not within specification, replace the return spring. Clutch piston 1. Verify that there is no air leakage when applying com- pressed air through the oil hole opposite the return spring. 2. Verify that there is airflow when applying compressed air through the oil hole on the return spring side. Air pressure: 392 kPa (4.0 kg/cm2, 57 psi) max. 3. If not correct, replace the clutch piston. Gartner Banana