Anybody Know What's Inside a PCV Valve?

[w30bob]

Hi Guys,

The reason I'm asking is I got a nice dirty rusty M37 PCV in a box of nuts and bolts from the swap meet and I was going to dunk it in hydrochloric acid (Muriatic Acid) for a quick bath. But I wasn't sure if the internals were just a metal ball and metal spring, or something the acid would destroy. Anybody ever taken one apart to see what goodies are inside?

thanks,
bob

[Cal_Gary]

Primarily a spring and a ball, but not all PCV valves are alike-the ball weight and spring tension varies depending on the engine. Using an incorrect one can really screw things up.
Gary

[powerwagontim]

The Donaldson valves do get gunked up, and are made to be dissassembled, cleaned and put back. If you shake it you should hear some movement inside.
Tim

[T. Highway]

I was wondering about the valve internals myself just last night.

I took mine apart cleaned the internal single part (a metal poppet) no sign of a spring. I media blasted the external portion of the valve and re-blued it. I then assembled it the same way I took it apart and started to wonder if there should be a spring inside.

I will post a picture of refinished valve tonight. It looks nice but I don't know if it will function correctly. I was going to call Charles later today and ask him about it.

Bert

[w30bob]

Hi Bert,

Can you tell me how you "re-blued" it?

thanks,
bob

[T. Highway]

Hi Bob,

I'll get the name of it tonight and post it along with the picture.

Bert

[jordankjcm]

Bert,

TM9-8030 has a nice diagram of the internals of that valve on page 165. No spring, just that round tapered metal piece (weight) looks to be inside.

Jeff

[jordankjcm]

Bert,

You have a PM.

JJ

[w30bob]

Hi Guys,

Jeff....you're right. I pulled one of my PCV valves apart (the Donaldson) and it had the pintle you describe without any spring or check ball. I also took apart two other PCVs that I believe go to the M38 Jeep. That one has a spring and a cone with an orifice at the top of the cone. Both were dirty and needed a good cleaning. I didn't have my camera with me or I would have posted some pics.

regards,
bob

[T. Highway]

I talked with Charles today and he confirmed what you guys are saying, no spring inside the valve.

Here is a picture of my refinished valve. I used Vans Gun Blue, this is a cold gun blue that if you use it on slightly warmed steel it will look and work as well as salt blue.



Bert