Hyundai Sonata 1991 Shop Manual page 429

GENERAL
SERVICE ADJUSTMENT PROCEDURES
Y45CYIA
INSPECTION OF TRANSAXLE FLUID QUANTITY
1. Place vehicle on level floor.
2. Before removing dipstick, wipe all dirt from area around
dipstick.
3. With selector lever in "P" park and parking brakes applied,
start engine.
4. Engine should be running at idle speed.
Transaxle should be sufficiently warmed up [fluid temper-
ature 70-80°C (160-180 0 F)].
5. Move selector lever sequentially to every position to fill
torque converter and hydraulic circuit with fluid, then place
lever in "N" Neutral position.
6. Check to see if fluid level is in "HOT" range on dipstick. If
fluid level is low, add automatic transaxle fluid until level
reaches "HOT" range.
Transaxle fluid :
GENUINE HYUNDAI ATF AUTOMATIC TRANSMISSION
FLUID, MOPAR ATF PLUS TYPE 7176, DIAMOND ATF
SP, BP AUTRAN MM SP (For Australia)
Low fluid level can cause a variety of conditions because it
allows pump to take in air along with fluid. Air trapped in
hydraulic circuit forms bubbles which make fluid spongy.
Therefore, pressures will be erratic, causing delayed shift,
slippy clutch and brakes, etc.
Improper filling can also raise fluid level too high. When
transaxle has too much fluid, gears churn up foam and cause
the same conditions which occur with low fluid level,
resulting in accelerated deterioration of automatic transaxle
fluid.
In either case, air bubbles can cause overheating, fluid
oxidation, and varnishing, which can interfere with normal
valve, clutch, and servo operation.
Foaming can also result in fluid escaping from transaxle vent
where it may be mistaken for a leak. Along with fluid level.
it is necessary to check conditions of fluid. When fluid smells
burned, indicating contamination with metal bushing or
friction material particles, a complete transaxle overhaul is
needed. Be sure to examine fluid on dipstick closely. If there
is any doubt about its condition, drain out sample for double
check. After fluid has been checked, seat dipstick fully to seal
out water and dirt.
REPLACEMENT OF TRANSAXLE FLUID
Refer to LUBRICATION AND MAINTENANCE PART.
45-40
HOT
Fluid level must be
within this range