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Author Topic: Finding and fixing oil leaks!  (Read 5541 times)
RickB
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81 MCI 9 smooth side 8V71 Allison 754




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« Reply #30 on: September 13, 2010, 09:22:34 PM »

You are running straight 40 wt conventional (non-synthetic) oil right? A buddy was running 10/40 rotella in his 6v92 and it was leaking/burning like mad and he switched to what most folks here run (straight 40 weight) and he started driving it more and voila! no more leaks and no more burning oil either. I have heard that synthetic is considerablt more leak prone than conventional oil.

Rick
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I will drive my Detroit hard... I will drive my Detroit hard.
RickB
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« Reply #31 on: September 13, 2010, 09:28:14 PM »

One other thought... any chance some of this oil is coming from the squirrel cage gearbox? Other than the obvious stuff that has already been suggested it was all I could think of. And you're sure it's not fuel correct?

Rick
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thomasinnv
Derrick Thomas
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« Reply #32 on: September 13, 2010, 09:54:14 PM »

it is most definitely oil, and it is most definitely coming out of the engine.  I run Delo 100 40wt.  it had delo 400 40wt when i got it.  I changed it out and drove 1800 miles since then and it's leaking more now then ever before.
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There are three kinds of people in this world....those that make things happen, those that watch things happen, and those that just wonder what the heck is happening. Which one are you?

1977 MCI Crusader MC-8
8V71N/740
95% converted (they're never really done, are they?)
RickB
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« Reply #33 on: September 14, 2010, 06:09:55 AM »

You have got yourself one gremlin of an oil leak. You will have to keep us informed as to how it turns out.

Inquiring minds want to know... ya know!

Sorry i couldn't help more

Rick
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Busted Knuckle
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« Reply #34 on: September 14, 2010, 04:49:23 PM »

If you wanna fix it once and for all and quit throwing $ at it I'd suggest you make a trip over Clifford's way and let the master find, & show you the problem and help you fix it RIGHT!
In my opinion ain't nobody closer or better!
FWIW JMHO!
Grin  BK  Grin
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Busted Knuckle aka Bryce Gaston
KY Lakeside Travel's Busted Knuckle Garage
Huntingdon, TN 12 minutes N of I-40 @ exit 108
www.kylakesidetravel.net

Grin Keep SMILING it makes people wonder what yer up to! Grin (at least thats what momma always told me! Grin)
thomasinnv
Derrick Thomas
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« Reply #35 on: September 14, 2010, 06:13:48 PM »

If you wanna fix it once and for all and quit throwing $ at it I'd suggest you make a trip over Clifford's way and let the master find, & show you the problem and help you fix it RIGHT!
In my opinion ain't nobody closer or better!
FWIW JMHO!
Grin  BK  Grin

that is probably just what I am going to do.  I will go ahead and fix the obvious leakers that I can see, and beyond that I will certainly accept the help.  I don't have the money to just throw at it.  I have ordered parts for and plan to replace the 1/4" tube and accompanying connectors at the back of the blower, replace the broken/missing 1" tube clips at the front of the blower, replace the oil switch that is literally dumping out oil, and replace the valve cover gaskets that are also dumping oil down the sides of the heads.  Those are blatantly obvious, beyond that I am not playing guessing games anymore.
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There are three kinds of people in this world....those that make things happen, those that watch things happen, and those that just wonder what the heck is happening. Which one are you?

1977 MCI Crusader MC-8
8V71N/740
95% converted (they're never really done, are they?)
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« Reply #36 on: September 14, 2010, 08:56:14 PM »

I don't have the money to just throw at it.  I plan to replace the oil switch that is literally dumping out oil, and replace the valve cover gaskets that are also dumping oil down the sides of the heads.  Those are blatantly obvious.

  Obvious oil leaks leak the most oil. I have a feeling that once those items are correct your gonna be okay.
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thomasinnv
Derrick Thomas
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« Reply #37 on: September 15, 2010, 05:48:55 PM »

A few days ago when i parked the bus i soaked the engine down with oil eater and sprayed it down really good.  (that stuff is awesome!)  it was so clean you could eat off of it.  anyway, today i had to move a few hundred feet to where we are setting up the tent getting ready for our revival to start tomorrow.  With it running in high idle i checked all around the motor and found that 2 of the air box covers are leaking pretty bad.  There is nothing at all coming out of the slobber tubes, so I am assuming they are plugged.  Do the tubes generally plug up?  or the elbow at the top?  or somewhere inside under the covers?  or a combination of all of the above?  what am I looking for?  I will probably dive in tomorrow based on what you all have to say on here.  a little guidance???

I tried to get some new gaskets for the covers but the best I could find was 2 weeks out.  I need to be rolling before then.  what would be the best way to seal these things up in the interim?  what kind of sealer/gasket material etc. can I use here?  or am i just out of luck?
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There are three kinds of people in this world....those that make things happen, those that watch things happen, and those that just wonder what the heck is happening. Which one are you?

1977 MCI Crusader MC-8
8V71N/740
95% converted (they're never really done, are they?)
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« Reply #38 on: September 15, 2010, 06:13:36 PM »

  Two weeks? for gaskets for an 8-71 ? Wow, thats almost scarey.
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lostagain
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« Reply #39 on: September 15, 2010, 06:21:48 PM »

Slobber tubes: fast idle might be too fast. It might be enough pressure to close the check valves. On regular idle, feel with your hand for air coming out of the tubes.

For the gaskets, I would cut some out of cork material you can buy at any auto parts store, and put them on with gasket maker for added peace of mind.

JC
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JC
Invermere, BC
1977 MC5C, 6V92/HT740
luvrbus
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« Reply #40 on: September 15, 2010, 06:31:53 PM »

Derrick, the gaskets for the cast valve covers are designed to be used more than once that is why they are hard to get, if you have a piece tore or missing just use a good silicone I use Ultra Black made by Permatex put it on the damaged areas and let set for about 30-45 minutes before installing the covers.  
Buy a tube and use a chalking gun it is lot cheaper than buying the stuff in the small tubes
While you have the covers off take the breathers apart and clean those wish I could help more but it is hard to tell what is causing your problem over the net I am beginning to think now you may have a problem up top also check the exhaust system and be sure the inside of the muffler hasn't come apart


good luck
« Last Edit: September 15, 2010, 06:43:12 PM by luvrbus » Logged

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Busted Knuckle
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« Reply #41 on: September 15, 2010, 07:14:29 PM »

Clifford you may be more on the $ than me, but I thought he was talking about the air box covers and drains on the side of the block. FWIW

Thomas what part of the country are in now? Maybe there is a bus nut close who would have better access to parts for you.
Grin  BK  Grin
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Busted Knuckle aka Bryce Gaston
KY Lakeside Travel's Busted Knuckle Garage
Huntingdon, TN 12 minutes N of I-40 @ exit 108
www.kylakesidetravel.net

Grin Keep SMILING it makes people wonder what yer up to! Grin (at least thats what momma always told me! Grin)
luvrbus
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« Reply #42 on: September 15, 2010, 07:27:46 PM »

I just remember him saying he was ordering valve cover gaskets I can send all the air box cover gaskets he needs or wants a 83 model 8v71 should be the same as a 8v92- 2 singles and 1 double on each side but the Ultra Black will hold there also and you were right BK


good luck
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thomasinnv
Derrick Thomas
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« Reply #43 on: September 15, 2010, 10:08:29 PM »

BK, I am in Fallon NV.  About an hour from Reno.

Clifford, in The last post I was talking about air box covers.  If the check valve were to close at high idle then I suppose the leakage would be expected considering the gaskets are in sad shape?  When looking around for leaks last week I noticed the airbox covers were extremely loose, most nuts barely hand tight and one nut missing.  I replaced the missing nut and snugged the rest of them.  The gaskets were oozing with heavy amounts of rtv from a previous poorly done job by the po, so may have squeezed the gasket out when I snugged the cover.  I did notice the oil leakage got worse after tightening some loose objects, so I suspect trying to tighten things up actually made it worse.

The valve covers are very tight and gaskets are leaking, so I just assumed new gaskets would be in order.  Learn something every day.

As for the airbox covers, I will try removing them and clean up the gaskets if possible and use a thin layer of black rtv and re-assemble.  If this proves to be of no success then I will be contacting you about the possibility of getting some gaskets from you.  Oh, and that tube on the back of the blower....I managed to find all the pieces but one nut for just a few dollars.  I can't find the one that goes on the bell housing side.  part #5144478.  wouldn't happen to have one laying around would ya?
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There are three kinds of people in this world....those that make things happen, those that watch things happen, and those that just wonder what the heck is happening. Which one are you?

1977 MCI Crusader MC-8
8V71N/740
95% converted (they're never really done, are they?)
Van
Billy Van Hagen
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89' Silver Eagle 15/40 6V92MUI Boulder City,NV




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« Reply #44 on: September 16, 2010, 02:34:29 PM »

Derrick, sent you a PM Wink
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