Finding and fixing oil leaks!

[thomasinnv]

update:  the beast is now leaking about a gallon in 200 miles.  The 1/4" tube does not seem to be leaking anymore, but just to be sure I am going to the Detroit dealer this week and picking up new o-rings.  I will also replace the oil sensor switch and valve cover gasket at the same time.  Then i will pressure wash the engine and see if I can find more leaks.  Leaking really bad now. 

[luvrbus]

Try driving 50 miles a gal low to see if the leaks slow down or if it uses anymore oil it maybe over full,let it set for 30 minutes and then check the oil those old engine hold a bunch of oil up top and takes a while to drain back

good luck

[JackConrad]

Bob my 8 was belt driven had 4 -3/8 in wide belts and was air cooled not oil cooled located on the drivers side.50 D gear driven have to be driven off the camshaft where are talking at the top is the blower drive they do have a auxiliary pulley you can belt drive from there but never saw a 50D gear driven mounted there.
Fwiw DD uses a special cam for the gear driven 50D and they brake lol just sent Don Fairchild one to replace a broken drive cam for a MCI.
A gear driven alternator if it was mine on a 2 stroke would be the 1st to go
good luck

Our original 8V71 in our MC-8 had the gear driven Alternator. The replacement engine that we installed had the pulley adapter installed where the gear driven alternator had been installed on the original.  Since all lighting (interior and exterior) is now 12 volt, we do not need much 24 volt output, a small belt driven truck alternator is adequate.  Jack

[bevans6]

I found a leak on mine, the vent line on the top of the DD50 was loose to the point of almost coming off, so I tightened it down and we'll see if it makes a difference.  If I think about it, that vent would probably only leak much when the oil was hot and less viscous, and when the alternator was spinning at high speed - highway travel.  The leak would be very misty - hence it got all over everything.  I hope  it helps, I'm tired of washing the car every single time I stop.

Brian

[RickB]

If you have a gear driven alternator I would recommend buying and installing a support bracket to revent future leaks as well and I found that my most serious leak was the air compressor and they can leak internally and externally.
The unloader was leaking oil into the motor which would find it's way out through the spitter tubes and some got burned as well (don't ask me how) and all over the rear passenger side of the block.

If your compressor is cycling alot and struggling to get up yo pressure you might want to consider a rebuild as mine was leaking alot.

I can sit in a parking lot running and have a single drop of oil in 10 minutes and that is coming from my home made spitter box catchcans,man does that feel good.

I am winning the war for the time being but I have to remind my wife and myself, we never actually win the war against two strokes leaking we just have brief moments when we aren't losing.

Rick

[RickB]

BTW you may be burning some or most of the missing oil as well... just a thought

[luvrbus]

Derrick, check and see if you have a tach drive on the back of the blower if you do they are bad about the bolt coming loose and the strap falling off that much oil if a external leak should not be hard to find.
Do you have the cast valve covers or the stamped metal ,if you have the old stamped metal style stop on the way back and I'll give you a set of the cast for a 8v71 without Jake Brakes I don't have the ones for Jakes



good luck

[thomasinnv]

Clifford,  I have been running it about a gallon low.  I always check the oil after sitting for a while, usually in the morning after sitting over night.  I verified the dip stick was reading the correct level after I changed the oil.  Oh, and that 1/4" tube...is that supposed to be a hard tube or a flexible tube?  Mine is a flexible tube that has a loop in it.  When you said it slides that got me wondering.  Also, no tach drive I don't think.  I have no tach anyway.  There really is no oil to speak of on the back of the bell housing, none of the accessories are leaking.  I can't seem to find clamps narrow enough for the hoses at the front of the blower, only find the wider ones.  Does DD have the clamps or just the plastic clips?  Oh, and I beleive I have the cast valve covers but I will double check that to be sure.

RickB,  I have a belt driven air cooled alt, and I am sure the DD is leaking most if not all of the oil being lost and not burning it.  I can pull in and park for 2 minutes and have huge puddles.  My white pickup is completely black and nasty.  it looks like a big square on the ground under the engine, you can see where it is dropping off of the engine.  The air compressor will only cycle maybe twice an hour rolling down the highway, and that is mostly due to a believed faulty/leaking front leveler valve.  I don't believe the slobber tubes are leaking much if any at all, the sides of the engine are covered in oil from the heads down, and the front is coated from the blower down.  The rear is pooled from the top of the block under the rear of the blower and down the sides of the bell housing.  No danger of this thing EVER rusting.  I'm hoping I don't end up with starter problems, that thing gets soaked pretty good.

Brian, as mentioned above I have a belt driven air cooled alternator.  No oil hose going to it.  Only oil hoses at the back of the engine go to the blower and there is one around the back of the bell housing that looks to be in a really bad spot if it ever needs fixed/replaced.

I am going to fix the few items mentioned in my previous post, and wash the engine off again and see what else I can find.  I have thought about loosening the blower shaft tube and rotating it 180 deg so the bottom is now on the top, so I can see if that is leaking or possibly cracked on the bottom.  It does not look like it from what I can see, but may be better to actually turn it over and get a good look at it.

And a note to every one that has taken the time to post their ideas and thoughts here...A BIG HUGE THANK YOU TO YOU ALL!!!!  I am a tent evangelist, this bus is our home and we appreciate your help.  For obvious reasons I can't afford to take it to a shop every time something pops up.

[luvrbus]

Derrick, you have the wrong tube it should 4 inches long straight and made of steel not copper,DD should have both style clamps the plastic will hold for about 5 years   
 
good luck

[thomasinnv]

Derrick, you have the wrong tube it should 4 inches long straight and made of steel not copper,DD should have both style clamps the plastic will hold for about 5 years   
 
good luck

Clifford, it is not copper it is braided high pressure stainless steel.  same hose as found in other locations on the engine, such as the oil pressure switch manifold.  Does not look like a scab job, looks like it belongs there, I'd have never guessed it wasn't original.  the tag on the motor says it's a 1981 if that makes a difference.  BTW, the valve covers are the cast ones.

[luvrbus]

They, do not use a hose somebody just didn't know how to install the tube and tried a easy wayout that you are paying for now it has to have the wrong fitting to make a hose work ,those are special fitting send me a shipping address and I will ship you the correct tube and fittings for the blower and end plate, but I don't have the 2 seals.
They have 2 different fitting for the blower end just tell me if the fitting is screwed into the blower plate or has 1/2 inch shoulder and the fitting goes past the plate and then screws into the blower



good luck

[thomasinnv]

They, do not use a hose somebody just didn't know how to install the tube and tried a easy wayout that you are paying for now it has to have the wrong fitting to make a hose work



good luck

It does not appear to be leaking, but that doesn't mean it's not.  Is this something that should be replaced back to oem anyway just for good measure?  I don't want to just blindly throw money at it, but I also don't want to overlook something so simple that may come back to haunt me later.  What would you do if it were yours?

[uncle ned]

On my 6v92 I had a leak . It seamed to come from behind the alt. I kept tightening it up but got worse. The oil ran down the back of the engine. and under the blower and all over the trans.

Removed the alt and replaced all gaskets. Made it worse.

Finally removed the alt and checked the adapter and found a almost invisable crack that got bigger when tightened down. new adapter cured the problem.

uncle ned

[artvonne]

  Man that is a LOT of oil, I sure hope you get it figured out. I am certainly no expert on DD, but when you say its leaking from the heads down, it really sounds like rocker covers (valve covers). The upper head rocker cover could dump an awful amount of oil onto the blower, and the rear head would ooze down the back and blow all over everything else. I think even if you dont suspect them, I would change them anyway, just to check it off the list. In fact, I would change any gaskets I could reach, starting with the easiest ones. Sometimes air turbulence can blow oil around and make it look like its coming from somewhere else. But when an engine is completely covered with oil from the top down, you gotta believe its coming from up high. Ive had many engines with loose rocker covers, and the amount of oil they can throw is amazing.

[thomasinnv]

I have 2 valve cover gaskets on will call to pick up.  The oil switch I am told the DD dealer does not have a listing for them and i need to get it from MCI as it was installed by them and not a DD item.  I will order the switch and just put in a 1/4" plug for now.  I am guessing the switch completes a ground to shut down the engine?  With the wire disconnected the engine still runs.