Engine/Transmission (1994 - 1998) Replacing semi-rigid fuel supply/return fuel lines on 98

[Johnstra]

I want to replace the fuel lines on my 98 - the semi-rigid lines that go from the the steel supply/return to the lift pump and hard line from OF valve. These are not rubber, they are quick-disconnect type lines that are semi-rigid. Who has replaced these? Did you just pull them off and replace them with good diesel rated lines?

Thanks,

-john

 

[CTD12V]

Hey John,



I think you can replace them with good diesel-rated marine hose. I am supposed to be doing this to my '98, too, if I ever get the parts ordered and the time to do it. I asked about this a week or so ago in a thread entitled "'98 Fuel Supply and Return Lines. " You may have seen it. A couple of other guys responded who had '98s and had replaced the factory lines. Good luck, and let me know how it goes if you get around to it before I do.



CTD12V

 

[Johnstra]

Thanks CTD, I'll take a look at your thread. And I'll let you know when I replace mine.

-john

 

[Vaughn MacKenzie]

Well I found out the hard way that the hard line going to the injection pump from the filter canister can break and leave you stranded. JB weld, duct tape and hose clamps only prolonged the inevitable. . . you will be FORD (found on road dead). In my case I was FORD in BFE Nebraska last week (at exit 85 on I-80). $420 + $59 later for the new braided SS hose from Cummins I was back on the road. I really recommend that anyone and everyone get the upgraded fuel line from Cummins if you go out on the road much. Mine burst at 389,600 miles but others have been known to break sooner. Once it's cracked you're done. The 12-valve lift pump is such a pumping machine that nothing is going to hold it adequately to limp you home.



Vaughn

 

[Johnstra]

Aw, there's worse places you could have been stranded. At least in NE it's hard for somebody to sneak up on you



Is there a part # for the braided SS line, Vaughn?



-john

 

[Bart]

I too want to know about this SS braided line. I have a lot of travelin' planned for this year and don't want to part on the side of the road.

 

[JGheen]

Please fill us in on this new braided line, I am very interested.



Joe

 

[CumminsPower98]

My steel return line from the overflow valve to the rubber line behind the fuel filter cracked last winter way up in Canada. I had lots of fun on a Saturday in the freezing cold wind getting the thing off. Lucky for me my cousin was also there with his truck (both RV transporting) and was able to run me around town for help. Dodge dealer didn't have a line and when I asked for some rubber hose to replace mine that I killed getting it apart they just gave it to me! My line was cracked almost all the way around. Next we drove around looking for a shop that could braze up my line and we found one that was closed but there was a guy there and the door was open. He did a nice job on it and didn't even charge me! Nice people up there. Anyway I got it back together and I'm still running on that brazed line probably 100k miles later. The filter to pump line cracked on a buss at my old work and I brazed it up and it ran that way for quite some time until I was able to replace it with the braided stainless one.



Food for thought. I think I caused the leak on mine from tightening the banjo bolt and slightly twisting the line putting a stress into it. It cracked down at the first mounting tab behind the P7100 on the top side. I am very careful now not to stress these things when tightening banjo bolts. I now carry spare fuel hose, clamps and a mini tubing cutter so I can make a repare along side the road if I need to.



I once worked on a '99 that had been to the dealer twice for cracked return lines. The guy brought it to me the next time and I brazed it up for him and installed it correctly and he never had another problem. I think the dealer was putting a stress on the line when installing it, causing it to break.

 

[DBazley]

This thread is helpful but I still have a couple of questions. First, the problem:



I'm getting fuel sprayed all over the suspension arms / engine bay upon high boost conditions - like towing heavy. Light demand conditions the leaking fuel doesn't seem to appear.



After reading this thread, one thing I am still curious about is how the semi-rigid braided fuel lines connect to the steel lines, or rather how to un-connect them.



On my '97 this junction is directly at the Drivers side frame rail as it bends up at the firewall. The lines appear to be some sort of heavy fabric woven material (to help pressure from bursting mere rubber lines ?)



I'll search other threads, but if any can comment on the procedure for removal of these special woven lines from the steel lines, and possibly a lesser expensive option than the $ 400 + Vaughn mentioned above that Cummins dinged him for, I'd surely appreciate it.



Big trip coming up, gotta fix it asap ! Thanks guys as always TDR comes through to the rescue !



David B

 

[JGheen]

How much pressure runs in those supply and return lines, isn't it no more than 30psi or something less?



Did anyone get the part numbers to those steel braided lines that Vaughn was refering to?



Joe

 

[ttbird]

Vaughn- Do you have the part # for that braided line? Thanks- Tom

 

[Joe G.]

It's the pressure spikes that cause all the problem in the supply line. Steady pressure will be mostly below 40 PSI but each time the big spring in the lift pump pushes the piston to pump another slug of fuel you get a pressure spike.

 

[Vulcan]

Just did a 12v the other day with JIC fittings and 250 psi hose, works great.

 

[Vaughn MacKenzie]

Sorry for leaving you guys hanging. Cummins part number is

3936691



Here's a couple pics showing it next to the patched up one.

 

[JGheen]

Thanks Vaughn,



Is that banjo on the new line smaller than the original or is it just the pic playing tricks on my eyes?



Is there a revised one for the return off the overflow valve as well? That steel braided section would be great for replacing that rubber line behind the fuel filter. Oo.



Joe

 

[Vaughn MacKenzie]

Same size JGheen, and I'm not aware of any upgrade for the return. Would be nice if that was braided SS!

 

[JGheen]

I replaced all my steel lines, both supply 3/8" and retrun 5/16" with marine grade rubber hose from Mr. Bob's Dist. . I have been using it for 18 months now and everything is great. Get rid of those bango's.

What did you do about the overflow valve?



Joe

 

[Vaughn MacKenzie]

What did you do about the overflow valve?



Joe

I wouldn't worry about the banjos on the return side (the only one being on the OF valve).



After seeing what an incredible pumping machine the lift pump was on my '96 when the fuel line blew there's no doubt the banjos present no significant resistance going to the injection pump. When my line busted my fuel gauge dropped 2 needle widths in HALF A MILE.



Vaughn

 

[DBazley]

Another fuel hose suggestion

I replaced all my steel lines, both supply 3/8" and retrun 5/16" with marine grade rubber hose from Mr. Bob's Dist. . I have been using it for 18 months now and everything is great. Get rid of those bango's.

Lots of good ideas here gentlemen for replacing or upgrading the fuel lines on our trucks - here's another.



Our local industrial supply house, Top Line Products of Temecula, provided me with a very affordable solution, which is perhaps as suitable as the marine grade hose. It's Weatherhead / Eaton 250 working PSI hose, with push-on Barb-Tite fittings. I looked up the specs on the mfr site and they say it's suitable for diesel fuel, water and air hose, and if the application required fittings, the push on fittings make it user serviceable - no crimping required.



In this case, I found my leak, but it wasn't the DC stock fuel hoses (I'm sure those are almost ready to pop !), but the Prime-Loc remote fuel filter system hoses that reach from the stock fuel filter location / adaptor to the remote mount (2 hoses @ 24" ea), that had developed a pin-hole leak.



This hose they supplied sure looks as strong or stronger than the stock Prime-Loc lines and it was easy to cut to length and push the end fittings on. I'll try to report back after some time on the integrity these lines show. The other nice thing was cost, this hose is just . 96 / ft retail and the fittings a buck or two each.



I'll surely consider using this line to replace the DC fuel & return lines ASAP if these two perform well.



Here's the URL for those hoses & fittings FYI:



http://hydraulics.eaton.com/products/pdfs/W-HYOV-MC002-E01_Hose_Low_Pressure.pdf



http://hydraulics.eaton.com/products/pdfs/W-HYOV-MC002-E01_Hose_Low_Pressure.pdf



Regards, David B.

 

[DBazley]

PS: I might have added: the hose I used, exactly, was "H 201 - General Purpose Hose" in 1/4 ".



DB