Fuel Leak - Page 2
 

Fuel Leak

Started by Emcemv, May 26, 2014, 01:09:10 PM

Previous topic - Next topic

Emcemv

Oh what a relief it is!  I found the leak, its at the straight fitting where it goes into the block, shown in the picture below.  I think Clifford hit the nail on the head, I think it is cracked, in the photo, you can see the coupling is hitting the housing and I'll bet its been pushing on the pipe until it cracked.  Thankyou sparkplug188, I ran the motor for about 30 seconds and then shut it off with the fuel lever (easy once you know how!) and the leak was real obvious.  I'm going to put a 45 on the pipe nipple to keep it away from the housing.  Is this the fitting that has the restriction orifice in it?? This is the high pressure feed from the fuel filter to the drivers side head.

The next crisis will be when it breaks off trying to get it out! ;D

Now that I've got it all apart, I'm going to replace all the coolant hoses I can and also replace my fan pillow block bearings that I knew were going.......one thing leads to another!

Thanks to all for the help!
Bruce & Nancy Fagley
1973 MCI MC-7 Combo Freighter
450HP DD 8V-92T 2000 Reman
HT 740 Allison
Woodbury CT.

luvrbus

The orifice is on the return line going back to the tank remove the fitting from the return line from the head you will see it or lose it ::)
Life is short drink the good wine first

bevans6

On my MCI engine the return fitting is on the back of the right hand head, near the fire wall (towards the front of the bus).  that line is a high pressure line into the head from the fuel filter.  I would maybe get a slightly longer pipe nipple to bring the hose fitting out a little further from the block.

Brian
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Allison MT-647
Tatamagouche, Nova Scotia

Emcemv

Brian, the longer nipple was my first thought also but I was thinking that longer would be more prone to vibration........over thinking it I'm sure.  I'm going to do that because any other solution requires a new fuel line too!

Thanks
Bruce & Nancy Fagley
1973 MCI MC-7 Combo Freighter
450HP DD 8V-92T 2000 Reman
HT 740 Allison
Woodbury CT.

luvrbus

Bruce, that is not the proper way to hook that up DD does not use a pipe nipple screwed directly into the head Mon I will email a photo to you showing the proper fitting. Since I cannot post pictures here email is the best I can do,you have 3 pieces on the run and it only take one with the DD fitting you buy at most Parker hose supply houses Throw that away and use a hose in the head would be better than that  
Life is short drink the good wine first

bevans6

FWIW, my MCI engine has the exact same fitting, a pipe nipple screwed into the head at that location.  I just swapped it over and left it, so it's still on my new engine.  Not to say it's the best, just what MCI (or the Navajo's) did on my bus.

Brian
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Allison MT-647
Tatamagouche, Nova Scotia

Emcemv

Clifford, thanks, very interested in seeing the picture, use the email listed in my profile.

Bruce
Bruce & Nancy Fagley
1973 MCI MC-7 Combo Freighter
450HP DD 8V-92T 2000 Reman
HT 740 Allison
Woodbury CT.

luvrbus

Your email and pictures have been sent Bruce and I have never saw that extension break or leak fwiw
Life is short drink the good wine first

Emcemv

I received pictures of the correct fuel fitting from Clifford.  Here is what it looks like.  Now I just need to find one!  Thanks for the photos Clifford!
Bruce & Nancy Fagley
1973 MCI MC-7 Combo Freighter
450HP DD 8V-92T 2000 Reman
HT 740 Allison
Woodbury CT.

RobSedona

great info guys I think I have the water pipe on mine also not the fitting like Clifford sent I will have to change it over before mine starts to leak :)

Emcemv

Did some more work on it today and as suspected, the pipe nipple broke right off at the head when I tried to remove it.  This was a normal brass plumbing nipple and it was cracked about halfway through....so there wasn't much holding it.  It could have been a real disaster if this had broken off while driving.  I got the piece out of the head with an easy out so now I'm ready to put a stronger fitting in.  I used a couple of 3/8" socket extensions to extend the easy out so I could turn it.
Bruce & Nancy Fagley
1973 MCI MC-7 Combo Freighter
450HP DD 8V-92T 2000 Reman
HT 740 Allison
Woodbury CT.

luvrbus

WW Grainer should have the extension they did sell them in Stainless and iron DD will have it the problem there is finding a old parts guy that can find the group number it is in.

If you don't find one drop me a PM with your address I have a extra or have a hose made anything is better than a nipple screwed into the head IMO  

A threaded brass nipple is very thin at the threads and they break I have broken one before by dropping a filter that hit the nipple

good luck
Life is short drink the good wine first