June 23, 2018, 09:09:45 PM

Author Topic: Servicing air vent check valves?  (Read 5116 times)

Offline bevans6

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Servicing air vent check valves?
« on: 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
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
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Offline robertglines1

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Re: Servicing air vent check valves?
« Reply #1 on: 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..
Bob@Judy  98 XLE prevost with 3 slides --Home done---last one! SW INdiana

Offline luvrbus

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Re: Servicing air vent check valves?
« Reply #2 on: 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
Life is short drink the good wine first

Offline tomhamrick

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Re: Servicing air vent check valves?
« Reply #3 on: 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
Tom Hamrick
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Offline bevans6

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Re: Servicing air vent check valves?
« Reply #4 on: 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
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Spicer 8844 4 speed Zen meditation device
Tatamagouche, Nova Scotia

Offline luvrbus

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Re: Servicing air vent check valves?
« Reply #5 on: 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
Life is short drink the good wine first

Offline bevans6

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Re: Servicing air vent check valves?
« Reply #6 on: 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!
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Spicer 8844 4 speed Zen meditation device
Tatamagouche, Nova Scotia

Offline luvrbus

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Re: Servicing air vent check valves?
« Reply #7 on: 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
Life is short drink the good wine first

Offline Van

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Re: Servicing air vent check valves?
« Reply #8 on: 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 :-*
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Offline bryanhes

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Re: Servicing air vent check valves?
« Reply #9 on: 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

Offline bryanhes

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Re: Servicing air vent check valves?
« Reply #10 on: 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

Offline Eagle Andy

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Re: Servicing air vent check valves?
« Reply #11 on: 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
1968 Model 05 Eagle # 7481 Miles City MT

Offline bryanhes

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Re: Servicing air vent check valves?
« Reply #12 on: 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

Offline luvrbus

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Re: Servicing air vent check valves?
« Reply #13 on: 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   


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Offline brando4905

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Re: Servicing air vent check valves?
« Reply #14 on: 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
1980 GMC H8H-649  8V71/V730 Marion,NC

"The highway is for gamblers, better use your sense" -Dylan