Failure is present and confirmed by Cat Dealer

[Dave Atherton]

Update: Hydraulic Hose used for fuel line on Caterpillar Engines, by Dave Atherton

Here is additional information that may narrow down what is happening with hydraulic hose
breaking down on the inside rubber center. What I have found myself being hands on 10
hydraulic hose used for fuel line, it looks like it is one brand name on hydraulic hose is failing.

Failed hoses that been removed Brand Name on hydraulic hose.  GATES GLOBAL  8G1
1/2 inch. 12.5 MM.  R-1.  8C1T/15N.  EN853.  2325 PSI WP  ( 16.0 MPa ) made in U.S.A.
10041502.  Y18020.  Looking at your motorhome, discharge hose coming off Racor Water/Fuel
filter to Cat engine suction side of fuel transfer pump. This is the hose that is failing and
flaking can cause failure to fuel transfer pump and injector failure by lack of fuel, fuel starvation.

Thoughts on why failure is starting to show up at this point in time and with one brand of
hydraulic hose failing with what I have seen so far. The BIO FUEL today is present at most
all fuel stops from label on pump 5 to 20 percent. My thoughts on motorhome builder and
year motorhome built, the hydraulic hose used did meet all spec for fuel at build and has not
bought about any problems untill now. We can go back 1996 to 2004 and today is 2016.
If possible maybe bad roll of hose out of spec ( if this the case failure would have happen long
before now.) this leaves one one thing left that has been ever changing BIO Fuel a little amount
at first now a lot. The cost of this repair to correct problem is around $ 35.00 but as Dick post
from Empire Cat reinforce my past post. There is a problem that cat very costly if not addressed.
Dave Atherton Retired Cat Mechanic

[Edward Buker]

Dave,

Thanks for the alert and to further define your brand observations. It does seem to be a manufacturer specific material problem (so far). To be clear, you said the hose that comes from the Racor water/fuel separator to the Cat suction side of the fuel transfer pump. From the Racor there is a hose that goes to the Cat final filter, from the Cat final filter there is a hose that heads to the engine which I think goes to the suction side of the transfer pump but I am not sure? I remember in an earlier photo the debris was coming into the Racor pre screen.

Can you take us through the flow and hoses and clarify this a bit when you get a moment....something like from tank to Racor prefilter OK if no debris in screen, from Racor prefilter to final filter, OK due to final filter stopping debris but if Gates consider change, from Cat final filter to transfer pump change if Gates? Your guidance on this would be appreciated.

Thanks Ed

[Dave Atherton]

Hi Ed, where problem is located is between Racor water/fuel filter discharge hydraulic hose
(1/2 inch) to the suction side of fuel transfer pump. This hydraulic hose is after the Racor
water/fuel filter and before fuel transfer pump suction. This hose is where failure of hydraulic
hose coming apart with rubber. The rubber is reducing fuel flow and fuel starvation to the
secondary fuel filters and fuel flow in fuel rail in head. note: the fuel lines  after the fuel transfer
pump go back to Cat OEM fuel hose. The hydraulic hose failure seems to be worse with the
C-12 and up because of increased fuel flow. The fuel transfer pump suction inlet when
restriction fuel flow reduced this gear type pump will fail and pump gears ( 2 ) will start
milling into pump body. The secondary fuel should in most cases prevent metal beyond
this point. Where the real damage is going to happen is injector failure ( via: injectors heating
up and seizing. Diesel fuel must maintain flow to cool injectors in head and return back to
fuel tank. This also goes back entry of air before fuel transfer pump and having cavitation
Loss of power and injector failure. total of 10 hydraulic hoses that have been replaced by
myself and all have been Gates Hydraulic hose as in earlier post. I also have a video cam
inside of failed hydraulic hose showing steel braid showing clearly reinforce inside center
failure. I also sent 2 failed hydraulic hoses removed to Cat Dealer I used to work for.
Yes there is a real problem but not a costly problem changing out one hose in question.
Dave Atherton Retired Cat Mechanic

[Dave Atherton]

Ed, to make this a little clearer. Fuel is pulled from front fuel tank to the Racor water/fuel filter.
Than discharge side of water/fuel filter to suction side of fuel transfer pump. At this point Fuel
hose goes back to Cat OEM fuel hose and fuel is sent to secondary fuel filter under pressure,
into fuel rail and into head and return back to front fuel tank. This is a closed loop system
that cannot have any air present. Dave Atherton Retired Cat mechanic

[Dick Simonis]

Now I have no idea if this observation is meaningful but...at idle speed the fuel level in the strainer was a bit above 1/2.  After the hose change the fuel level was about 1/4.  To me, this suggested that more fuel was flowing at that rpm.  Not necessarily that the engine was burning more just that more was flowing through the re-circulation loop.

Like I said, this may mean nothing but it's an observation that repeated itself and to my semi analytical mind that is goes beyond coincidence.

Dick

[Dave Atherton]

Dick, you are correct you are moving more fuel, why because the failure of hose you replaced
and suction going to fuel transfer pump is not restricted with flaking of rubber from failed hose.
Point in question fuel starvation, little or no smoke. If you have a sliver leaf you should note
increase in fuel pressure also.

Today at Perry, Ga we changed out  hydraulic hose fuel line on C-12 leaking before crimp
on hydraulic fitting at fuel transfer pump. 2000 Beaver motorhome. This is hose number 11
Dave Atherton Retired Cat Mechanic

[Edward Buker]

Dave,

Thanks, that was clearer, especially your second post. I will check and see what I have for a fuel line on mine. For some reason I imagined that the pump was between the final filter and the Cat engine...I was confused :-)

Dick I have observed the same level change in the strainer when I have changed fuel filters, the flow was improved and the result of that was a lowering of fuel level in the screen strainer. Different reason that I had less flow resistance, but observed the same result.

Later Ed   

[Dave Atherton]

Fuel hose update, Michael Rump Beaver Cat C-12 hydraulic hose change out. Mike is also
changing Racor water/fuel to Caterpillar fuel/water filter setup.  Air entering system at
filter setup. Mike is going to have Cat in Perry build fuel hose in question. Mike had posted
rubber in site glass last Dec and got all parts wanted myself to check system at Perry before
He started project.  Last thing update on failed hydraulic hose, again Gates Gobal except
this time we can see very clearly with all the info numbers. MADE IN INDIA maybe this
Will shed some light on the problem. Going to look at hose we changed out yesterday to
see where it's made but think Gates Gobal the made in part may all be. Made in India,
it is very hard to get all information because of age and weather cracking of rubber outside.
Dave Atherton retired Cat Mechanic

[Daniel McShane]

Last week I took my coach in for its routine service to Quinn Cat in Oxnard Ca. They are a fairly large dealer here in Southern California with many locations and have been doing all the engine work on my coach since I bought it. I told the tech about the problem with the fuel lines and had them replace the line from the primary filter (water separator) to the transfer pump as suggested. Unfortunately, I forgot to ask about the condition of the hose or to have them save it for me.

          TOTAL PARTS....................$30.06
          TOTAL LABOR....................$330.60
          HOSE ASSY CHG................$  15.00
          MISC CHG.........................$  15.00

          TOTAL..............................$375.66

I wish I would have found out the condition of the fuel line so I wouldn't think I was wasting money but now I have one thing less to worry about while driving down the road.

About 2 1/2 years ago I had to have the fuel fill lines and vent hoses replaced because they would leak fuel when tank was full, the hoses were brittle and cracked. I have recently discovered a hose (1/2 in?) coming from the rear of the cylinder head and returns to the fuel tank. I would assume this is a pressure relief or fuel return to the tank and has minimal pressure. I had Quinn Cat look at this but they quoted me a price of around $5K to replace 30 ft of fuel line. Mechanic said they would have to drop the front cross member and tank to access where the hose clamps to the tank. I haven't had this replaced yet, the hose is cracked and deteriorating but doesn't leak. I may have to try and crawl under there myself.

Thank You Dave Atherton!!

[Stan Simpson]

@ Dave Atherton. Can you say what era of Beavers this applies to? All of them. Perhaps a date range? Thank you.

[Mike Groves]

Dave and All, where can I look to inspect this hose on my '99.  Pretty sure there's no rubber sitting in my clear glass water separator but I wanted to see if this is a Gate Global.  Maybe I am missing something but there doesn't appear to be rubber hoses in my filter cabinet at the back passenger side of the coach.  From reading, it appears this is the hose coming from the tank feeding the primary fuel filter.  Where's the best place to look at this hose?

Mike

[Gerald Farris]

Mike,
The hose that is in question here is the one that runs from the outlet side of your Racor primary filter/water separator to the lift/transfer pump that is located on the engine at the passenger's side towards the very rear of the coach. If this hose starts failing, the rubber particles can restrict and/or damage the transfer pump before being trapped in the secondary filter. However, if the hose between the fuel tank and the primary filter starts to deteriorate the particles will be caught in the transparent prescreen at the primary filter to give you plenty of warning time to change the hose before a fuel starvation problem develops.

Gerald       

[Mike Groves]

Thanks Gerald, I'll try to locate it next time I visit the coach.  From what vantage point is it easiest to see? 

Mike

[Dave Atherton]

Mike and Stan, looking at 1996 to 2004 than fuel system changed over to plastic fuel
hose. What has been found wiping off outside of hydraulic hose, you will see number
in white to indentify spec's on hose and company. It appears the hoses removed that have
failure maker of hose Gates Global, found one hose from Micheal Rump Beaver yesterday
maker name  Made In India. Other hydraulic hoses have made in USA on hose but both
made in India and made in USA with company name Gates Global and have same spec's
printed on hose. My suggestion if hydraulic hose has Gates Global I would remove and replace
your hose. There is enough information present failure has happened.
Dave Atherton Retired Cat mechanic

[William Jordan]

Last week I took my coach in for its routine service to Quinn Cat in Oxnard Ca. They are a fairly large dealer here in Southern California with many locations and have been doing all the engine work on my coach since I bought it. I told the tech about the problem with the fuel lines and had them replace the line from the primary filter (water separator) to the transfer pump as suggested. Unfortunately, I forgot to ask about the condition of the hose or to have them save it for me.

          TOTAL PARTS....................$30.06
          TOTAL LABOR....................$330.60
          HOSE ASSY CHG................$  15.00
          MISC CHG.........................$  15.00

          TOTAL..............................$375.66

I wish I would have found out the condition of the fuel line so I wouldn't think I was wasting money but now I have one thing less to worry about while driving down the road.

About 2 1/2 years ago I had to have the fuel fill lines and vent hoses replaced because they would leak fuel when tank was full, the hoses were brittle and cracked. I have recently discovered a hose (1/2 in?) coming from the rear of the cylinder head and returns to the fuel tank. I would assume this is a pressure relief or fuel return to the tank and has minimal pressure. I had Quinn Cat look at this but they quoted me a price of around $5K to replace 30 ft of fuel line. Mechanic said they would have to drop the front cross member and tank to access where the hose clamps to the tank. I haven't had this replaced yet, the hose is cracked and deteriorating but doesn't leak. I may have to try and crawl under there myself.

Thank You Dave Atherton!!

What is it about this hose that is  so much money to replace ? Almost 3 hours ? I would think it to be 15 30 minutes once the hose is made .