Posted by Clint dixon [172.68.90.97] on Wednesday, January 03, 2018 at 10:06:40 :
In Reply to: Suction at oil filter tube posted by Russell Somers [172.69.70.26] on Wednesday, January 03, 2018 at 03:16:07 :
Whether or not you feel suction or not at the filtered air inlet on the side of the oil filler neck depends upon a lot of variables: Are all of the oil seals and gaskets on the engine in good shape and sealing? Is the oil filler tube sealed to the block? Is the oil filler tube cap sealed to the tube? Is the Donaldson valve clean inside? Is the Donaldson valve tubing and fittings sealed to the engine block. Are your piston rings in good shape and sealing preventing abnormal blow-by?
You can clean the Donaldson valve by disassembling it. If everything is working properly, you should hear the Donaldson valve close after shutting down the engine. It may be immediate or it may take a few minutes. You will hear a distinct metallic "ping" as it closes. It sounds like someone just took a hammer and tapped your manifold. Vacuum from the manifold causes it to open. Gravity, and the lack of vacuum, causes it to close. There are several different models of the Donaldson valve. Some have their male and female pipe threads reversed. If you install the wrong version, it will be in-line backwards and will not function.
Junior