Community Forums

Cummins8.3 · 08-23-2011, 01:25 AM

I have a couple of leaks, 1 at the fuel line on an injector and 1 on the fuel line at the high pressure pump. I was going to replace the fuel lines myself but wasn't sure if I was opening a can of worms trying to Bleed the Fuel system when I'm done with it? The Coach starts up and runs fine. Only issue is the 2 leaks. I did tighten both fuel line nuts, (17mm nut size? ) and it did slow leak down. I was afraid of stripping nut so backed off on leverage a bit.
I know I can order parts ( new fuel line for specific Injector # from Cummins, I have my engine serial number and they will ship. My only concern is the Air I let into system once I removed both fuel lines. I also want to change both of my fuel filters, 5 year old fuel has been in tank, still running well but getting old. I live in Las vegas and it gets hot every summer, tomorrow will be 110 degrees.

Only 1000 Miles put on it in the 5 years I've owned it. 40,000 total miles when I bought it. I changed engine and tranny when I got it home from a 600 mile trip from seller. Have only put several hundred miles on since I changed the fluids. Fluids are new but sitting for 5 years.
It's a 1992 Safari Ivory with a Cummins 8.3 Turbo Diesel ( mechanical, no computer ). I've change a few gas engines in the past ( when I was young ) and pretty sure I could do it myself, or would it be better just to have a shop in Las Vegas or Henderson, Nevada do it? I do change my owe engine and tranny fluid.

Please let me know your thoughts and if you have any good Cummins 8.3 mechanics in the Las Vegas Area, if you think I should use a mechanic.
Below are a couple of pictures of the leaks I'm having.

Thanks for any advice. AL
1992 Safari Ivory
8.3 Cummins
Allison MT643

grumpy14 · 08-23-2011, 07:09 AM

check if lift pump has a primer--if it does no worry onair in lines --if not, loosen lines on injectors and turn engine over untill you get pressure then tighten

grumpy14 · 08-23-2011, 07:12 AM

if you can, prime fuel fiters--now here is where someone will say i,m dumb-but try prime with atf fluid, cleans injectors on start up

HeapBigEngin · 08-23-2011, 10:52 AM

A couple comments re my experience with fuel leaks on our 2003 ISC....may or may not apply to your engine. After replacing a leaking lift pump, I noticed a leak at injector line #6 (I think), the shortest and closest to the fuel pump. Unfortunately, in order to get to the #6 line, the other 5 lines had to be removed....and that's when I took the coach to my Cummins dealership. As explained to me, the problem with removing the other lines is that they develop a "seat pattern" at the fuel pump and at the engine (caused by the original installation as well as vibration over time). Too often, tightening the line can make the leak worse....it did in my case. The Cummins guys said they would change and warrant the one leaking line, but could not promise the 1 or more of other 5 would not leak after the repair. I subsequently verified the concern with another independent shop. I bit the bullet and had all 6 lines replaced....no leaks now after 16 months. Most of the expense at that point was for the additional 5 lines, since the tech was already working in the area. Unsure if the line configuration and routing on your coach is similiar to mine.

Funny....each line is unique due to twists and turns. Number 6 was out of stock at Cummins, and we had to locate it in Texas. The other 5 were available from Cummins. That tells me that Cummins may have had a more than a few #6 lines replaced. Just a thought....

IMHO, unless you have the facilities and experience to do this on an expensive diesel, I would suggest you leave it to the guys who work on 'em every day. I am pretty capable mechanically, but I would not attempt it on our coach (especially since I warrant my own work!!). If you don't have to remove any other lines, that would be a good thing and much less expensive.

Hope this helps....and PLEASE let us all know how you make out. Thanks....