Question 1

When inspecting valves from the valve body: Technician A says the edges of the spools should be damage-free but should not be sharp.Technician B says to identify a bent valve, install it into its bore and rotate it. If it binds or drags while it is being rotated, it is bent. Who is correct?

Accepted Answer

Both technicians provide valid points for inspecting valves. Technician A is correct in saying that the edges of the spools should be damage-free and not sharp to ensure proper operation. Technician B is correct in suggesting a method to identify a bent valve by installing it into its bore and rotating it to check for binding or dragging. Therefore, both technicians are correct.

Question 2

While discussing boost pressures: Technician A says during certain operating conditions, mainline pressure must be boosted. Technician B says increased pressure is needed to hold brakes and clutches more tightly, such as in reverse or high load conditions. Who is correct?

Accepted Answer

Both technicians are correct. Boost pressures are necessary during certain operating conditions to ensure proper operation of the transmission. Mainline pressure must be increased to provide more holding force for the clutches and bands during high load conditions, such as in reverse or when towing heavy loads.

Question 3

Which of the following is not a type of valve used in the valve body?

Accepted Answer

Poppet, spool, and check ball valves are commonly used in a valve body. Stator valves are not typically used in valve bodies.

Question 4

Which of the following accomplishes the distribution of pressurized fluid to the appropriate reaction member?

Accepted Answer

The valve body is responsible for controlling the flow and distribution of pressurized fluid to the appropriate reaction member in a hydraulic system. It contains various valves and passages that regulate the fluid flow and direction. The screen filter, check valve, and oil pump are all components that work in conjunction with the valve body but do not directly accomplish the distribution of pressurized fluid.

Question 5

Technician A says the oil pan bolts must be discarded after removing the pan from Ford fusion-based FWD vehicles. Technician B says when replacing the pan on this type of vehicle, a thin application of sealer must be used to ensure no leaks occur. Who is correct?

Accepted Answer

Technician A is correct because some Ford Fusion-based FWD vehicles use torque-to-yield bolts for the oil pan, which are designed to stretch upon installation and must be replaced once removed. Technician B is correct because a thin application of sealer is often required on the oil pan gasket surface to ensure a leak-free seal upon reinstallation.

Question 6

While discussing shift pressure control valves: Technician A says that these valves can apply different pressures to a clutch pack depending on the commands from the TCM. Technician B says that modern transmissions do not use shift pressure control valves.. Who is correct?

Accepted Answer

Technician A is correct, shift pressure control valves can apply different pressures to clutch packs based on commands from the TCM. Technician B is incorrect, modern transmissions still use shift pressure control valves.

Question 7

The spool valve's movement is controlled by:

Accepted Answer

The spool valve's movement can be controlled by hydraulic pressure, spring pressure, or mechanical linkage depending on the specific system's design and application. Therefore, all of the options (A, B, and C) are correct.

Question 8

Technician A says when assembling parts of a transmission, especially a valve body, to always use new gaskets and seals and to lubricate each part with clean ATF. Technician B says to increase the applied torque by 15 percent when reusing bolts and other fasteners. Who is correct?

Accepted Answer

Technician A is correct in recommending the use of new gaskets and seals and lubrication with clean ATF. This ensures proper sealing and smooth operation of the transmission. Technician B is incorrect in recommending an increase in applied torque when reusing bolts and fasteners. This can lead to over-tightening and potentially damage the parts. It is always recommended to follow the manufacturer's specifications for torque values when reusing bolts and fasteners.

Question 9

Technician A says that the pressure switches used in automatic transmissions measure the pressure and send the information to the TCM. Technician B says that the pressure switches only indicate if pressure is present; they do not indicate the exact measurement of pressure. Who is correct?

Accepted Answer

Pressure switches used in automatic transmissions only indicate the presence or absence of pressure, they do not measure or indicate the exact pressure measurement. Therefore, Technician B is correct. Technician A is incorrect in stating that the pressure switches measure the pressure and send the information to the TCM.

Question 10

Technician A says a pressure test can verify problems with valves inside the valve body. Technician B says the valve body on most transmissions can be serviced while the transmission is still in the vehicle. Who is correct?

Accepted Answer

Technician A is correct, as pressure testing is a common method to check valve problems inside a valve body. Technician B is also correct, as most valve bodies can be serviced without removing the transmission from the vehicle. Therefore, both A and B are correct.

Question 11

Technician A says to flat file the surface of a warped valve body, to allow it to seal properly helping to prevent unwanted, partial engagement of a clutch or band. Technician B says valves sticking in their bore may be the result of overtorquing the hold-down bolts of the valve body. Who is correct?

Accepted Answer

Technician A is correct because a flat file will smooth out any irregularities on the surface of a warped valve body, allowing it to seal properly and prevent unwanted partial engagement of a clutch or band. 
Technician B is also correct because overtorquing the hold-down bolts of the valve body can cause the valve to bind in its bore, leading to sticking. Therefore, both technicians A and B are correct.

Question 12

Technician A says throttle pressure is controlled directly by the pressure regulator valve. Technician B says one of the primary purposes of the pressure regulator valve is to fill the torque converter with fluid. Who is correct?

Accepted Answer

The answer of Technician A says throttle pressure is controlled...

Question 13

Which of the following is true of a vehicle speed sensor?

Accepted Answer

All of the options are correct statements about a vehicle speed sensor. It generates an AC signal as it detects the rotation of a reluctor ring with teeth or slots. It typically uses a permanent magnet and senses the speed of the output shaft, which is the speed of the vehicle's wheels.

Question 14

Technician A says mainline pressure is the source of all pressures in a transmission or transaxle. Technician B says mainline pressure is used to apply clutches and bands. Who is correct?

Accepted Answer

Mainline pressure is the highest pressure in a transmission or transaxle and it serves as the source of all other hydraulic pressures. This pressure is used to apply clutches and bands, as stated by Technician B. Therefore, both technicians are correct.

Question 15

Technician A says on some Chrysler transaxles the solenoid/pressure switch is a single unit that consists of various solenoids and pressure switches. Technician B says on some General motors transmissions the fluid pressure switch assembly contains five different pressure switches and is connected to five different hydraulic circuits. Who is correct?

Accepted Answer

Both technicians are correct. Some Chrysler transaxles do have a solenoid/pressure switch that is a single unit consisting of various solenoids and pressure switches. On the other hand, some General Motors transmissions have a fluid pressure switch assembly that contains five different pressure switches and is connected to five different hydraulic circuits.

Question 16

Technician A says that a relief valve exhausts fluid flow when a particular pressure is reached. Technician B says that a relief valve prevents pressures from going too low. Who is correct?

Accepted Answer

Technician A is correct that a relief valve will exhaust fluid flow when a certain pressure is reached, as its purpose is to relieve excess pressure in a system. Technician B is incorrect; a relief valve does not prevent pressure from going too low, but rather prevents it from going too high.

Question 17

Technician A says engine load can be monitored electronically through the various electronic sensors that send information to a TCM. Technician B says the most commonly used load sensor is a VSS. Who is correct?

Accepted Answer

Engine load can be monitored electronically through various sensors such as the MAP sensor, MAF sensor, and throttle position sensor (TPS), sending information to the TCM. The VSS (vehicle speed sensor) is not a load sensor but measures the speed of the vehicle. Hence, Technician A is correct, and Technician B is incorrect.

Question 18

Technician A says valve bodies are disassembled in the same way for most transmissions and transaxles. Technician B says to read the service manual for the proper procedure before disassembling a valve body. Who is correct?

Accepted Answer

Technician B is correct because the disassembly process can vary significantly between different models and manufacturers, making it essential to consult the service manual for the correct procedure.

Question 19

Technician A says valve body springs are distorted if they roll straight on the workbench when removed from the valve body instead of wobbling. Technician B says problems rarely result from excessive clearance between the valve and its bore. Who is correct?

Accepted Answer

Valve body springs are supposed to roll straight on the workbench when removed from the valve body; rolling straight indicates they are not distorted. Problems often result from excessive clearance between the valve and its bore, contrary to what Technician B suggests.

Question 20

Technician A says a transmission orifice is a bore in a passage that is larger than the connecting passages. Technician B says an orifice is used to dampen a fluid flow to prevent sudden or undue movement of a control valve. Who is correct?

Accepted Answer

The answer of Technician A says a transmission orifice is...

Quiz 7: Hydraulic and Electronic Controls