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Collapsed/Kinked Fuel Line repair

148K views 37 replies 23 participants last post by  WyoRick  
#1 ·
Just wanted to show how I fixed a couple of kinked/collapsed hoses on my truck after discovering TSB# PIP4526. This is what the TSB says:

TSB #PIP4526: Diesel Engine Fuel Line Repairs - keywords DTC hose kink loss P0087 P0093 P1093 pipe power reduced repair restrict restriction SES suction supply vacuum - (Nov 7, 2008)

Subject: Diesel Engine Fuel Line Repairs
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The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:
A dealer may need to perform a repair on the rubber portion of the fuel supply (suction) lines. The rubber section of the line could become kinked or collapse. Fuel lines that kink or collapse may induce a fuel system restriction (high vacuum gauge readings) or DTCs P0087, P0093, and/or P1093 to set.

If a technician was to suspect the rubber portion of the fuel feed line collapsing or kinking, replacement of only the rubber line is acceptable.

Recommendation/Instructions:
Complete the steps below to repair the rubber section of fuel supply line:

Carefully cut, split, and remove the OEM crimp from both ends of the flexible hose. These crimps can be cut with a small cut-off wheel. Split the crimp into two pieces (use your discretion on first cut location, then cut directly across from, or 180 degrees from first cut). Special care must be taken not to damage the flare on the end of the steel pipe that will be reused.
Remove the OEM crimps and flexible portion of hose from the existing supply line.
If replacing the rubber section of the supply line, a 1/2 ID hose meeting SAE specification 100R3 is suggested. Dealers may be able to find a local supplier for this hose, or can contact the manufacturer Parker Hannifin. The replacement hose would be a 1/2" diameter Parker part number 601-8 or H017-8. To find a local distributor the Parker website can be accessed.
Use worm type hose clamps (use double clamps on each end) to attach the replacement hose to the existing pipe.



The above picture shows how kinked my supply line on the engine was. I replaced both sections of braided rubber hose on the supply line. One is on the left side of the engine by the glowplug controller, and the other to the drivers side of the transmission.



Using a dremel with a small cutting wheel I cut the permanent crimps off of the rubber braided lines. I started from the rubber side working my way towards the metal tubing. The crimp butts up to a flare on the metal line. I stopping cutting just before this flare to avoid damaging it. With the majority of the crimp cut I was able to insert a flat tip screwdriver and pry the crimp apart. Using the screwdriver and prying the crimps apart allowed me to get by without making opposing cuts per the TSB. The above picture shows where the lines were getting weak and where I made my cut.

After getting the oem crimps removed it was as simple as cutting hose to length and installing them with double hose clamps on each end. The next three pictures show what I ended up with.





Note: You may want to disconnect the supply line from the tank if your doing the line next to the tranismission, it is lower than the tank and will not stop leaking. I chose to try and be quick and ended up with a decent amount of fuel on me.
 
#2 · (Edited)
Were you getting any of the fuel codes thrown, or did you do this as a pre-emptive approach?

If you were getting codes, did this repair make the condition cease and self-clear the codes?

Thanks for the pictures.
 
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#3 · (Edited)
07keo02,

Nice write-up and pictures. I'll save this one for future use.
 
#4 ·
I was not getting any codes. I have suspicion of having a weak cp3 as I seem to have low power when towing. I have never driven a duramax before I bought this one in April so it is hard to judge. With all my research I found this TSB and inspected my lines. I would think even if they weren't affecting performance, they surely were causing excess strain on the cp3 for who knows how long. The big thing with these lines are, they may not look collapsed on inspection, but after towing for long periods of time, the fuel starts to get very hot, so our trucks being a suction design (no lift pump) the lines will collapse if they are getting old or weak, especially in the bend sections. If your are getting any low pressure codes while towing for long periods, and can't diagnose any issue testing under no load, I would definitely consider replacing these lines.
 
#5 ·
I just replaced mine. Used the Parker 601-8 hose as recommended. My old lines were weak and collapsed just like the DIY. My truck was also throwing the P0087 code when towing uphill. Haven't towed again yet but I'm sure the collapsed hoses were the problem.
 
#6 ·
Did it fix the P0087 code? I am throwing them left and right when I tow my 5th wheel. Seems to be happening going uphill between 1800-2000 rpm. I can make it up a little then I see blow smoke out the tail pipe and then it throws the code....frustrating.
 
#7 ·
Whats the details of your truck and miles, mods etc?
 
#8 ·
Ha! Sorry about that here is my Sig updated. Right now I am at 185,000 miles
 
#9 ·
This should not be the issue for you with your raptor 150. Your lines are under pressure. Does it happen on the stock tuning as well? It is possible that your cp3 is getting weak.
 
#11 ·
Well I have dp5 selector with Idaho Rob tunes. I can WOT in the 150 extra Hp tune with no codes thrown. I would think that with the Raptor pushing the fuel I would not have he problem. Dsauka did you have a lift pump on yours or just straight stock? Any way to test the CP3? Gonna start doing a thread search to find out.
 
#13 · (Edited)
I had an 03 that would run the same tune (rear wheel hp) level as my 08. So that's the same basic fuel flow needs, but the 08 would fall on its face about 60% of the time, more so when hot. Made no sense. Found the engine side fuel hose by the drivers side rear valve cover flex line kinked. Cut it out per the TSB and installed the new fuel hose and hose clamps. Drove it, took a few minutes of WOT to purge the air. Stopped and bled fuel filter again, then drove again. All issues resolved in my 08 now. I am surprised what power I picked up. Less surging up top RPM as well. Was ready to install a lift pump, no longer needed now. Truck is quieter as well.
 
#15 ·
I too had low power when towing under load. Under heavy acceleration it woul through a low rail pressure code. I previously installed a 2 micron Racor final filter. I found the tech. Service bulletin about the collapsed fuel lines so I took it into the dealer. They checked it out but told me they would do the fuel lines but could find no indication of any fuel line collapse. While researching the problem, I came across a tech. bulletin that said basically that the Duramax engine was very sensitive to low rail pressure & any modification of any kind to the fuel system, such as additional filters or more restrictive filters would make the problem worse. I removed my 2 micron filter & the problem was greatly improved. Now I get only a slight power loss under heavy load when my OEM filter shows 50 percent life or less. I've just gotten into the habit of replacing the fuel filter every 5K miles. I also have been using Stanadyne fuel additive & a Biocide with every fill up.
I cut open every filter that I change out & I've had some nasty stuff once or twice from bad fuel. Not so much since using the biocide.
 
#16 ·
I dont know if anyone still reads this but I had a question. IN the engine compartment where the line was collapsed/kinked as shown above, I removed both lines. The fuel is 1/2 ID but what is the other? What dose it go to? I noticed that most people are actually only replacing the 1/2 and that kinda worries me
 
#17 ·
same type of connector, same type of hose, right? If so, then one of the lines is the fuel supply line, under pressure [probably 60+ psi], and the other line is just the fuel return line, back to the fuel tank. There's a fuel pressure regulator that keeps the fuel pressure in the rails correct, and releases fuel through the return line as necessary to keep it there.
 
#18 · (Edited)
Duramax has no positive pressure from tank side on 1/2" supply line unless owner has added a lift pump. CP3 is a suction pump that pulls from tank.

Smaller line is 3/8" return to tank.
 
#22 ·
Thanks for posting these instructions! I did this replacement last weekend. I will not know until our next trip in August whether or not this fixed my issue.

I did want to add a note that may help other people. On my 2008 the line by the transmission was about 11" long and the line in the engine area was about 4.5" long. I mention this because I did not see it in the thread and did not know how much hose to order and ended up ordering way more than I needed. Hope this helps someone!

Also, cutting the factory clamps was easy on 3 out of 4 of them. The most difficult clamp was in the engine area that was the closest to the ground. My dremel did not really fit without moving/removing the hose that goes to the intercooler/turbo (at least I think that is what that hose is for, my Duramax knowledge is very much lacking).
 
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#35 ·
Thanks for posting these instructions! I did this replacement last weekend. I will not know until our next trip in August whether or not this fixed my issue.

I did want to add a note that may help other people. On my 2008 the line by the transmission was about 11" long and the line in the engine area was about 4.5" long. I mention this because I did not see it in the thread and did not know how much hose to order and ended up ordering way more than I needed. Hope this helps someone!

Also, cutting the factory clamps was easy on 3 out of 4 of them. The most difficult clamp was in the engine area that was the closest to the ground. My dremel did not really fit without moving/removing the hose that goes to the intercooler/turbo (at least I think that is what that hose is for, my Duramax knowledge is very much lacking).
You mentioned Wolf Creek Pass? Like between Helena and GF? I-15?
I used to fly fish all through there! It’s AWESOME!! I do miss the Rockies, but I do not miss the cold!
Thanks for your post! It helped me out greatly!!!
CHEERS!!
 
#24 ·
It looks like it might have fixed the issue. We went camping last weekend and towed in the mountains with no issue. I was accelerating up the hills with the A/C going and had no codes thrown. The real test will be in August when we go on a 2 week camping trip.

I should mention that I also changed the fuel filter just in case it was the issue, so maybe that helped too.
 
#25 ·
Just got back from our trip and we had no error codes! We towed over Wolf Creek Pass and a few other smaller passes, which is a pretty good test.

Now I need to figure out my cooling issue. First thing I am going to look at is the cooling stack to see if there is a bunch of junk built up.
 
#28 ·
if diesel fuel isn't leaking in the area, and you aren't spraying a metal fuel line with sparks so it starts glowing, there isn't much to go wrong. a rubber line, put a sheet metal shield in front of it.
 
#29 ·
I used my used oil pan and dumped the fuel in with my used oil.

Yes, I was worried about cutting the line too but if you are very careful and cut in the correct location the fuel does not come out until you pull the line off. You will be cutting metal so there will be some sparks flying. I used a dremel with a small cut off wheel.

Also, be careful to not go too deep or you will cut into the flare on the metal line. You need that flare in good condition so your new hose can seal around it.
 
#30 ·
Having a lot of trouble with my '08. Just replaced the rubber lines that come off of the filter, next will be the short kinked line on the drivers side of engine. It is the one I suspect is giving me the most trouble. I'm getting the code unloaded not towing but under heavy acceleration. Cts2 shows rail pressure maxing out around 10k when it's asking for like 25k. Hopefully I'll get to do it tomorrow night.
 
#31 ·
I'm sure this is a thread from the dead BUT.... I had a c4500 duramax with the 6.6L LLY that was giving me some grief when pulling a load up a grade. Engine would slow to a 10MPH crawl and wouldn't get better until we pulled over, let the truck cool down and disconnect the battery to reset the truck.
Welp i found this thread and got some 601-8 and some clamps and got to cutting. Which SUCKED! lol i only cut one side then scared the other side and took a screw driver in and pryed them off. I had 3 MAJOR kinks on 3 different lines. The replacement hoses fixed the problem. We were pulling a monster grade from a stand still with a 12K# trailer and it did great. Until it did it again.... When i got the truck back in the shop i found the last hose that i had to replace which was above the fuel tank.... I had to drop the tank the replace it. BUT i am fairly certain the truck should be 100% now after changing the kinked fuel hoses.