Proportional soleniods: failure due to contamination
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1. Contamination sources of PWM solenoids are the same as on/ off solenoids
- parts failure
- fuzzy magnet
- solenoid screen filter contamination
- permagunk (friction material accumulating in low flow areas)
2. Contamination will often plug up the filter screens on the solenoid.
3. Most linear solenoids are quite large and have super-sized coils to move that a heavy spool and armature very quickly. The exception is the Chrysler gov pressure solenoid.
4. An internal magnet allows this solenoid to be small, however this creates a new set of problems.
- Internal magnet hops up the coil.
- Magnetism attracts magnetic debris, especially when vehicle is sitting still. This shroud is supposed to prevent that from occurring.
- Be careful with placement of pan magnets. This can neutralize the operation of the solenoid.
Click on an illustration to see an enlargement.
© Scott Kirkendall
Other related articles:
On-off solenoids: Failure due to contaminationOn-off solenoids: Failure due to wear
On-off solenoids: Failure due to abuse
On-off solenoids: Failure due to heat
On-off solenoids: Failure due to electrical causes
PWM solenoids: Failure due to contamination
PWM solenoids: Failure due to wear
PWM solenoids: Failure due to abuse
PWM solenoids: Failure due to heat
Proportional solenoids: Failure due to wear
Proportional solenoids: Failure due to abuse
Proportionalsolenoids: Failure due to heat
Replace and reuse rules
Failure review chart