Cummins M-11 and ISM Fuel leak

[Bob Belter]

Ahoy,Cummins guys.

Just had an "interesting" fault with my Cummins M-11 in my Eagle Bus.  Small diesel fuel leak after a trip to Las Vegas over Thanksgiving.  Ran the  engine, and saw some diesel leakage on the right side of the engine (and bus) in the cylinder head.  Fuel line fitting leak.  Went to tighten it, and the fitting broke off.  It was certainly cracked by vibration.  Left a busted off brass fitting in the cylinder head.  Line was from the pump to the head.  If gone  ---  NO RIDE!!!  Maybe a fire!!!  The fitting was a 1/8" mpt x JIC -- done in brass  --  Way too small.  Connected to it was a 3/8" copper tube. 

How to keep the trash out of the injectors while removing it?   Juiced the hole in the head with some some grease from a grease gun and long needle (for doing ball joints) to plug the hole.  Tried an 'easy-out'.  No luck!!!  And ---  a busted off steel device in the "wound" would have created even more entertainment.  Drilled and tapped.  Result:   I got it out OK  Blew the hole with WD-40 and a lomg plastic tube,   Then a brass tube plus an air hose.  I'll replace the fitting  with a steel fitting and a flex braided staimless steel/ teflon line.  Should be OK. 

This is the first thing that I have seen on this Cummins engine that was not 'perfect'.  The designer who put that scrawney little fitting into the engine needs to have a 2x4 whacked upside the head (his head!!).  May be hard to do now, 'cause he may by now be a VP!!!

For you Cummins guys, I'd suggest a look to see if this 'weinie' has committed mischief elsewhere, and replace any of these scrawney little brass fittings with steel fittings.

Enjoy  /s/ Bob 

[Tom Y]

Bob, Thanks for the heads up.  You said pass side? How far back? I need to look at my L10, as I can not picture this line and fitting. What year is your Eagle? What trans do you have? Mileage?  Thanks Tom Y

[Bob Belter]

Ahoy, Tom,

The fitting is on the side of the head, just above the fuel pump.  Your L-10 may be different.  I spoke with Cummins in San Leandro, and the person had seen this failure before.  I'd sure suggest that as a minimum, you replace the fitting with steel.

Eagle -01 1967  Transmission is a Roadranger overdrive RTO1110.  10th gear OD is 0.78, and the axle is 3.333:1
Fuel mileage???  Please send me your email address --- rhbelter@comcast.net, and I'll tell all.  I don't want to ruin a lot of DD-two cycle/ Allison 740 folks day (night) in this public forum.

Enjoy  /s/   Bob

[buswarrior]

Come on Bob!

I want to see how my ISM/Roadranger with 4.11:1 compares....

happy coaching!
buswarrior

[RJ]

Buswarrior -

Since when have you had a Cummins in your MCI???

Last time I saw your coach, you had an 8V71/HT-740. . .

OR is this in some new "secret" project you haven't shared with us yet?

[Bob Belter]

Ahoy, Tom Y and Buswarriior,

I've sent direct emails to you.  Buswarior  --- you are running.  How do you do on fuel mileage?

Enjoy  /s/ Bob

[buswarrior]

Settle down, settle down...

The ISM/Roadranger is in a Freightshaker.

8V71/740 works just fine, and will continue to do so.

I have to find some numbers and do the math.

happy coaching!
buswarrior