1994 MAZDA MX-5 oil pressure

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

K TRANSMISSION DIRECT CLUTCH Preparation SST CLOCKWISE 49 0378 375 Compressor, clutch spring Preinspection Direct clutch operation 1. Install the direct clutch onto the drum support along with the seal rings. Apply compressed air through the oil passage as shown. For removal 1 installation of direct clutch Air pressure: 392 kPa (4.0 kgtcm*, 57 psi) max. 2. Verify that the side plate moves toward the snap ring. If not, the seal ring or O-ring may be damaged or fluid may be leaking at the piston check ball. Inspect them, and re- place as necessary when assembling. Clearance between side plate and snap ring 1. Measure the clearance between the side plate and the snap ring. Clearance Maximum: 0.2mm (0.008 in) i -, 2. Select and install the correct side plate when assern- bling. One-way clutch operation Insert the fourth gear clutch hub on the top of the direct clutch, and verify that the fourth gear clutch hub rotates smoothly when turned clockwise and locks when turned counterclockwise. If not, replace the one-way clutch. 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

TRANSMISSION K 21. Insert the fourth gear clutch hub on the top of the direct clutch and verify that the fourth gear clutch hub rotates smoothly when turned clockwise and locks when turned counterclockwise. If it does not, then the one-way clutch is installed upside down. Caution Applying compressed air to the assembled clutch pack for longer than 3 seconds at a time will dam- age the seal. 22. Install the direct clutch onto the drum support along with the seal rings. Apply compressed air to the oil passage and check the clutch operation. Air pressure: 392 kPa {4.0 kglcm2, 67 psi) max. Gartner Banana

K TRANSMISSION FOURTH GEAR BAND SERVO Preinspection Fourth gear band servo operation 1. Apply compressed air through the oil passage as shown. .J Air pressure: 392 kPa (4.0 kg/cm2, 57 psi) max. 2. Verify that the piston stem moves to the brake band. If not, the seal rings or the oil seal may be damaged or the piston assembly may be sticking. lnspect them, and re- place as necessary when assembling. 45UOKX-183 Disassembly I Inspection I Assembly 1. Disassemble in the order shown in the figure, referring to Disassembly Note. 2. Inspect all parts, and repair or replace as necessary. 3. Assemble in the reverse order of disassembly, referring to Assembly procedure. 1. Brake band 2. Band strut 3. Fourth gear band servo cover 4. Gasket 5. Nut 6. Washer 7. Body 8. Piston stem 9. Piston assembly is assembly note . . . . . . . . . . page K-77 10. Seal rings 11. O-rings 12. Return spring Inspection . . . . . . . . . . . . . . . . . page K-77 Gartner Banana

TRANSMISSION K Disassembly note Piston assembly Remove the piston assembly from the body by applying compressed air through the oil passage hole. Air pressure: 392 kPa f4.0 kg/cm2,57 psi) max. Inspection Return spring 1. Measure the spring specifications. I Outer dia. I Free length I No. of tolls I mm (in) mm {in) mm {in} 2. If not within specification, replace the return spring. Assembly procedure 1. Apply ATF to the new seal rings, and install them onto the body. 2. Apply ATF to the new O-rings, and install them onto the piston assembly. 3. Apply ATF to the piston assembly and body. 4. Apply even pressure to the perimeter of the piston, and install it into the body. 5. Verify that the piston can be turned by hand. If it cannot, then remove it and check for damage to the seal ring. 6. Apply ATF to the piston stem and washer, and install them into the body. 7. Loosely tighten the nut. Gartner Banana

K TRANSMISSION t- FREE LENGTH 7 -& WIRE DIAMETER Disassembly note Drum support Mark the fourth gear case and the drum support for prop- er reassembly, then remove the drum support. Accumulator plug Remove the accumulator plug, piston, and spring by ap- plying compressed air through the oil passage. Air pressure: 392 kPa (4.0 kg/cm2, 57 psi) max. Inspection Drum support 1. Apply ATF to the new seal rings and install them into the seal ring grooves of the drum support. 2. Measure the clearance between the seal rings and the seal ring grooves. 4 Clearance Standard: 0.04--0.16mm (0.0016--0.0062 in) Maximum: 0.40mm (0.016 in) 3. If not within specification, replace the drum support. Spring 1. Measure the spring specifications. Specifications I Outer dia. I Free length I No. of I mm linl mm linl mm iinl Wire I 2. If not within specification, replace the return spring. Assembly procedure 1. Apply ATF to the new seal rings, and install them onto the accumulator piston. Gartner Banana