Air Pressure Tests
AIR PRESSURE CHECKSNOTE: Air passages can be tested adequately with air pressure regulated at 40 psi. It may be necessary to use air pressure of 90 psi if there is difficulty in hearing clutches apply.
Air Pressure Check Plate:
1. To properly perform air checks, it will be necessary to use Air Pressure Check Plate No. T82L-7006-A, with cap screws No. T82P-7006-C, and air nozzle No. 7000-DE with rubber tip No. 7000-DD, or equivalents.
2. Remove main control valve body, then install air pressure check plate, with valve body gasket, torquing cap bolts to 80-97 in lbs.
Air Pressure Test Diagnosis:
3. Apply air to apply passages in apply plate using air nozzle with rubber tip.
Air Pressure Testing Reverse Clutch:
4. To check reverse, forward, intermediate, and direct clutches, apply air pressure to appropriate passage in apply plate. A dull thud can be heard or felt on case as clutch piston is applied. Movement of the reverse clutch drum may also be detected when the reverse clutch passage is pressure tested.
Air Pressure Testing 3-4 Accumulator:
5. Apply air pressure to 3-4 accumulator apply passage and ensure that accumulator piston unseats, if equipped.
Air Pressure Testing 2-3 Accumulator:
6. Apply air pressure to 2-3 accumulator apply passage and check whether accumulator piston unseats by inserting small metal rod into 2-3 piston hold. When piston unseats rod will move and a dull thud can be heard when piston applies.
Air Pressure Testing Overdrive Servo Apply:
7. Apply pressure to overdrive O/D servo apply passage. Operation of band is indicated by tightening of band around reverse clutch drum. O/D servo will return to release position as a result of spring force from the release spring. When servo returns to release position, a thud can be felt on O/D servo cover and band will relax.
Air Pressure Testing Low Reverse Servo:
8. Apply air pressure to low reverse servo apply passage. A dull thud will be heard when the low reverse band tightens around the planetary assembly drum surface and movement of the ring gear can be detected.
Air Pressure Testing Line-To-Governor:
9. Apply air pressure to line-to-governor passage while holding finger near governor valve. If air is felt exiting valve area, passage is unobstructed.
Air Pressure Testing Governor-To-Valve Body:
10. Remove governor and apply air pressure to governor-to-valve body passage while holding finger over holes in output shaft. If air exits one of the holes, passage is unobstructed.