Fuel supply line disintegration

[Dave Atherton]

Joel, that is a very good point and my thoughts over the years many mfg. have jumped
into the hydraulic market. Looking at failure of hydraulic hose rubber center with video
camera, what a person can see tracking of hose break down or flaking down to braid wires.
( note: this is single ply hydraulic hose and once inside rubber started to break down
to braid wires than leaking to outside of hose. My thoughts like Steve mentioned all of
problem is starting to stand out, being a suction line in question the 15 to 20 percent
bio-fuel and higher horse engines pulling more fuel. Want to thank Fred for taking and
sending these pictures for me, I tried before on my earlier post when bringing this problem
out but did not know how to. Point to think about like Steve mentioned bio-fuel ( when did
Bio-fuel get its born on date and at what percent. Funny thing plastic fuel line seems to
Start at 2004 and our only problem now is the o-ring connections. Fuel restriction, air in
fuel system we already know is present in several motorhomes, first failure will be the fuel
transfer pump than air in fuel system as in picture number will cause heating problem and
injector failure along with low power. Dave Atherton Retired Cat Mechanic

[Steve Huber Co-Admin]

Joel, Dave,
Gates specs neoprene as the synthetic "rubber " component in their hydraulic hoses. I checked a couple of web sites for the compatibility of neoprene and bio-diesel. It seems to fare no better than natural rubber. (Links should download pdf files).  http://r.search.yahoo.com/_ylt=A86.J7zZvp1WlUUAAkQnnIlQ;_ylu=X3oDMTByYnR1Zmd1BGNvbG8DZ3ExBHBvcwMyBHZ0aWQDBHNlYwNzcg--/RV=2/RE=1453207385/RO=10/RU=http%3a%2f%2fbiodiesel.org%2fdocs%2fffs-performace_usage%2fmaterials-compatibility.pdf%3fsfvrsn%3d4/RK=0/RS=j0eWfYVp5OkFoqx1TsYqmvlf0RE- (IMHO, another reason to avoid the stuff when possible).
Note that the Kelco report (2008) indicates diesel fuel (assuming non-bio) is not particularly toxic to neoprene. http://r.search.yahoo.com/_ylt=A86.J7zZvp1WlUUAAUQnnIlQ;_ylu=X3oDMTByb2lvbXVuBGNvbG8DZ3ExBHBvcwMxBHZ0aWQDBHNlYwNzcg--/RV=2/RE=1453207385/RO=10/RU=http%3a%2f%2fwww.kelco.com.au%2fwp-content%2fuploads%2f2009%2f02%2fneoprene-chemical-compatibility-guide.pdf/RK=0/RS=KMG53vrKJMA7YJ5RWrj4X4A3Mo4-   Also there are numerous postings re the deterioration of "o" rings and other rubber components in automotive fuel system applications linked to the intro of bio diesel.
Steve

[Dave Atherton]

Thanks Steve, have ran into problems with hydraulic hose and o-rings. Myself I keep coming
back to using Cat made parts, that way there is no gray area what will work with a Cat
engine. Dave Atherton Retired Cat Mechanic

[Dick Simonis]

Question;  When you were surveying coaches at Quartzsite did you see any C-12's with plastic fuel supply line??  Reason I ask is that mine looks more like plastic than rubber and is connected to the fitting with a hose clamp vs. of a swagged fitting.  I base this on the fact that it won't dent if pressed with a screwdriver like the sheath on the hydraulic hose.

Second question, what are the secondary filter hoses??  Mine are painted yellow but one would think that if they have a failure issue you would send contaminants right to the injectors.

[Joel Weiss]

I couldn't open the link Steve provided, but here's the Gates hose-fuel compatibility chart:  http://www.gates.com/oreilly/tech_tips/AlternativeFuelsandHoseCompatibility.pdf

The issues appear to occur at temps above 125F (underhood temperatures)

Here's an excellent discussion of the fuel hose issue specifically (it's should be noted that most of the concern is for the use of B100 (pure biodiesel) which most of us will never encounter): http://www.biofuels.coop/education/resources/solvency-effects

[Steve Huber Co-Admin]

Joel,
The links don't open. They just download a pdf doc to your download file.
Steve

[Joel Weiss]

Joel,
The links don't open. They just download a pdf doc to your download file.
Steve

The PDF is the link; just read it and I just added another one.

[Dave Atherton]

Dick, yes there were several cat C-9 and C-12 with plastic fuel lines but also had the o-ring
connection which is another problem allowing air to enter fuel system on the suction side
of fuel transfer pump. Note : C-12 fuel transfer pump is a gear type pump that is a positive
Displacement that will create lot of suction and pressure that has a relief valve at pre-set
pressure. Note: second picture of plastic tube on the Racor filter set up ( lot of air moving
fuel at engine idle ) speed engine up all foam. What causes low power in a electronic engine
is air in fuel system, what causes damage to injectors is low air in fuel system. Rubber debris
at suction side of fuel transfer pump ( reduction of fuel and pressure to injectors ). Last
question secondary fuel filter fuel hoses ( these are Cat OEM fuel lines that fuel is under
pressure going into the secondary fuel 1R-0749 fuel filter for Cat C-12 engine. To answer
in a different way the aftermarket hydraulic hose stopped at the transfer pump suction side.
Dave Atherton Retired Cat Mechanic

 

[Dave Atherton]

Gentleman, little more information on fuel line disintegration. Last 3 days have been
Working with the Alpine motorhome group doing Diagnostic work on engines. I had the
Chance to look at many Alpine motorhomes mainly the fuel systems, ( all the units have
Cummins engines ). Year bracket 1998 to 2008 and what I had found the fuel system
setup from factory starting at fuel tank and going to motor. Note like Beaver there not
built anymore but I did like seeing all plastic 1/2 inch fuel line with all crimp -8 JIC hydraulic
fittings. There were 70 or more motorhomes present and was invited to the Diesel Round
Table. Talking with many owners the fuel system has never been any problems even that
Cummins use a different fuel filter ( the build of the fuel system may be something for
Beaver owners to look into.)  Dave Atherton Retired Cat Mechanic

[Dave Atherton]

Good morning, fuel line disintegration update (Caterpillar Dealer is has the correct
fuel line on hand to correct our problem between the primary fuel filter and the
fuel transfer pump). Today we are working on 2 fellow beaver motorhomes fuel line
problem. Will update tonight with cost and parts needed that can be bought from any
Caterpillar Dealership and install by beaver owner. Dave Atherton Retired Cat Mechanic

[Dave Atherton]

Gentleman, have a parts list for hydraulic hose disintegration repair. Need:  44 inch long Cat
9X-2374 fuel hose, cost .36 inch $ 15.84, crimp hose fittings  -8 JIC female swivel $ 8.69
Part number 92752 need: 2 , cost $ 17.38, Adapter part number 96515 steel fitting 37. C5315
$ 3.32. Note: adapter is used on the fuel transfer pump on C-12, C-13, C-15 engine only
suction inlet. C-9, C-7, 3126 E, B, A model do not need this adapter.

Fuel/water filter ( if you choose To go with Cat Parts ) 137-4367 filter base, 129-0375 plastic
Bowel, 133-5673 filter element,  120-6726 elbow fittings need: 2 total cost $ 153.52
All parts were bought at Empire Cat and any Cat Dealer should have the part numbers in there
system. Today 2 motorhomes were repaired with fuel hydraulic hose problem with Cat parts.
Dave Atherton Retired Cat Mechanic