Servicing air vent check valves?

bevans6 · November 12, 2009, 05:42:29 AM

My 8V-71 seems to slobber from one side only. How do you tell if the check valves are operating correctly? Can you service them, beyond just replacing them? Also, I was always of the impression that there where two slobber tubes on each side, front and rear, but I can only find one on each side. Are there two or one slobber tubes on each side of an 8v-71?

thanks, Brian

robertglines1 · November 12, 2009, 05:51:29 AM

I had only one on each side.one was plugged ...I took apart cleaned and reinstalled. spring and plunger on inside pay attention to which side spring in on...not a hard job..

luvrbus · November 12, 2009, 06:01:27 AM

One on each side is normal but they can be install at the front also, make sure the check valve is on an angle when you clean and install it never install the valves on a true 90 degrees.

good luck

tomhamrick · November 12, 2009, 10:18:44 AM

Hey Clifford, I am not sure about the angle of mine, but can you explain why they should not be 90 degree. I am assuming you mean straight down?
Thanks,
Tom Hamrick

bevans6 · November 12, 2009, 10:56:54 AM

On mine, they come off the block close to horizontal. You want them of something of an angle so they drain efficiently.

Brian

luvrbus · November 12, 2009, 12:12:06 PM

Bevans, to test the valves you should have air at idle coming from the drains and no air at the drains above 900 rpm fwiw where did you guys come up with the term slobber tubes is that a bus nut thing lol

good luck

bevans6 · November 12, 2009, 12:27:09 PM

I personally call them air vents, or alternatively those darn tubes that drain oil all over my driveway! But everyone else seems to call them slobber tubes and it seems somewhat appropriate!

luvrbus · November 12, 2009, 12:42:55 PM

Bevans, I wasn't trying to give you a bad time but 1 guy sent me a pm asking how he could stop his droller tubes from leaking and that was a new one for me they have always been knowed as air box drains to me.What ever you call it they are nasty when not working right

good luck

Van · November 12, 2009, 01:02:34 PM

Puke tubes, just like a harley, one day nothing the next, Blaaaaa! LOL

I'll go quietly now

bryanhes · November 12, 2009, 07:54:57 PM

I made a slobber tube catch tank for mine that works well for about $30 and a couple hours including fabricating the brackets to attach to the engine block. It was a whole lot cheaper to make than pay over $200 that Walker Mfg. wanted.

Here are a couple pics.

HTH,
Bryan

bryanhes · November 12, 2009, 08:08:20 PM

Here is a picture of it mounted. I used 3/4" flat bar and formed it around the tank. Then bent to angles to bring it above the bottom of oil pan.

Bryan

Eagle Andy · November 14, 2009, 06:18:13 PM

Hey Bryan , Thanks for the pics , Iam finishing up mine this weekend and I like the vent you used . Did you built that or buy it . Nice job Thanks Andy

bryanhes · November 15, 2009, 08:43:57 AM

Andy,
I bought it at Oreilly auto parts. It is just a crank case vent. They run about $10. Can get them at probably any parts store. One thing I did do is when I tapped the PVC. I also cut a threaded female coupler into small nuts basically to put on the inside so that the fittings would not come out of the PVC.

Glad that helps,
Bryan

luvrbus · November 15, 2009, 09:00:43 AM

Well guys the catch cans are nice but you need to check those every day I agree with Cole on this you are covering up the best diagnostic tool that came with the engine it will tell whats going on and what side, just my 2 cents worth and I also have the catch can

good luck

brando4905 · November 15, 2009, 09:05:30 AM

Luvr,

Do you mind explaining why the catch can needs to be checked everyday? Thinking about making one for my replacement engine.

Thanks,
Brandon