Old Fuel Lines

Topic: Old Fuel Lines (Read 3881 times) previous topic - next topic

Old Fuel Lines

January 16, 2013, 09:23:43 pm

If your diesel fuel lines are more than ten years old, you may wish take special care to inspect them for cracks, leaks, and seeps.

D'oh! Generator kept failing to run. Diagnosis at FOT was "bad fuel lines." Today Alton and crew replaced all the diesel fuel lines for the generator and the C-8.3. They pulled the 149 gallon fuel tank, replaced fittings with appropriate compression fittings, and replaced all the lines with new style lines.

They reported, and showed me, the seeping fittings and cracking lines. They told me I was probably fortunate that I did not have a failure of the "big" engine because of air in the fuel lines. They are replacing lots of fuel lines on coaches that were built around 1997.

They reported that an owner of a coach of similar vintage came in for service recently. The engine died before he got into a parking spot. The engine would not start again because of the volume of air invading the fuel lines. They pushed the coach about Camp Foretravel and into the shop with a specially rigged fork lift. That's a much better deal that requiring a tow at the side of the road.

Re: Old Fuel Lines

Reply #1 – January 16, 2013, 10:06:53 pm

I'll take a few close-up pics of the 30 foot fuel hose I just replaced -- when I'm back over there this Saturday to maybe use as a comparison to what your main feed hose is looking like these days.

The severe cracking on the O.D. was consistent along the entire length. So -- it's not a heat-related (due to location to a heat-exchanger, exhaust piping, etc), or too tight of a radius over time -- issue. It definitely is a failure from the deterioration of the material, starting at the I.D. and ultimately allowing the suction side of the delivery system to pull air right through the hose wall.

Regards,

Michael

Re: Old Fuel Lines

Reply #2 – January 17, 2013, 09:29:26 am

Quote from: J. D. Stevens – January 16, 2013, 09:23:43 pm

They pushed the coach about Camp Foretravel and into the shop with a specially rigged fork lift. That's a much better deal that requiring a tow at the side of the road.

Picked the rear wheels up off the ground? That would be interesting to see.

Re: Old Fuel Lines

Reply #3 – January 17, 2013, 09:49:15 am

Quote from: Chuck Pearson – January 17, 2013, 09:29:26 am

Picked the rear wheels up off the ground? That would be interesting to see.

My understanding was that they have a gadget on a fork lift that plugs into the hitch receiver. I think they push or pull the vehicle via the receiver.

Re: Old Fuel Lines

Reply #4 – January 17, 2013, 10:03:58 am

Here is how Rocky Mt Cummins pushed our Foretravel

Bob
2000 U270

Re: Old Fuel Lines

Reply #5 – January 17, 2013, 10:08:14 am

JD,
Did they drain your fuel tank to remove and then refill with the drained fuel? I guess they could not attach the fuel lines without removing the tank??

Thanks,

Re: Old Fuel Lines

Reply #6 – January 17, 2013, 10:15:54 am

I would have thought they would make a unit that fits in both of the rectangular tubes either end of the hitch cross beam. That way you have a more even loading as there is a lot of weight going on that hitch when unit is just off ground.
John H

Re: Old Fuel Lines

Reply #7 – January 17, 2013, 10:32:35 am

Quote from: Brad – January 17, 2013, 10:08:14 am

JD,
Did they drain your fuel tank to remove and then refill with the drained fuel? I guess they could not attach the fuel lines without removing the tank??

Yes, they drained the tank and then put the fuel back (mostly). Yes, they had to get the tank out in order to properly put in new fittings and attach the new hoses. It was a bit of a challenge to prime the system after installation because the fuel level was so low. One guy put air pressure on the tank, one operating the manual prime pump, one was cracking injector lines, and one was turning the key and operating the accelerator. They also used an additional battery to crank the engine faster. It appears that priming is much easier with a full tank of fuel!

Some pictures are attached.

Re: Old Fuel Lines

Reply #8 – January 17, 2013, 10:39:04 am

Quote from: John Haygarth – January 17, 2013, 10:15:54 am

I would have thought they would make a unit that fits in both of the rectangular tubes either end of the hitch cross beam. That way you have a more even loading as there is a lot of weight going on that hitch when unit is just off ground.
John H

John,

I think they are just pushing or pulling the coach. I don't think they are lifting. Of course they would have to release the parking brakes with air or manual intervention.

It would also be challenging to steer the coach with no hydraulic pressure. I tried that once when our steering gear was leaking. It could be done with great effort. My shoulders were sore the next day.

Re: Old Fuel Lines

Reply #9 – January 17, 2013, 12:13:15 pm

The coach that broke down in the FT camping area was ours. We had just arrived in Nac.. after a 360 mile drive and after disconnecting the toad, the coach died in the exact best place in the world to have this happen. All fuel lines were replaced and yes they did lift the rear with a fork truck and pushed us into a bay with Alton steering. Then on the return trip, we lost break air pressure 1 mile from a nice RV park. Had to bypass the air dryer and limp into the park, remove the dryer unit, return to FT to have it rebuilt, then replace back on the coach. The interesting thing was each of these problems developed on Fri. afternoons, prior to long holidays, which meant no work was done until the next Wed. Norm H

Re: Old Fuel Lines

Reply #10 – January 17, 2013, 04:02:39 pm

Next obvious question...how much did the stay at FOT set you back?

Re: Old Fuel Lines

Reply #11 – January 17, 2013, 08:00:23 pm

has anyone used nylon diesel fuel line tubing for the runs through the bays with rubber hose on the ends ? Gam

Re: Old Fuel Lines

Reply #12 – January 17, 2013, 10:21:20 pm

The Country Coach my friend has here in San Carlos that we are working on has plastic fuel lines, both feed to filters and return and with quick release fittings at ends. He has a leak before filter that we could repair easy. Seems a lot easier to replace too.
John H

Re: Old Fuel Lines

Reply #13 – January 17, 2013, 11:11:49 pm

I watched FOT replace fuel line in an SOB last year when we were there. It looked like the pex or whatever it's called we have for water lines.No soft covering.

Re: Old Fuel Lines

Reply #14 – January 18, 2013, 12:46:42 am

Here is a quote from a fuel line supplier. Looks like hose with a "B1" marking every 12 inches is the ticket. Note the mention of fire resistance as well as permeation.

Quote

"A diesel fuel hose can be used for a number of marine and fuel extraction purposes. To maintain safety and quality standards, diesel fuel hoses are rated for specific applications using a combination of a number and a letter.

The US Coast Guard (USCG) has rated four types of diesel fuel hoses, A1, A2, B1 and B2. According to the USCG recommendations, all marine applications must use the Type B hose at fuel pump and carburetor sections of the fuel line system. A leakage at these sections can cause huge loss of fuel. Also, the Type B diesel hose is fire resistant, minimizing the risk of a fire outbreak. The USCG also recommends the Type 1 hose for critical applications due to their low permeation characteristic. Coast Guard standards require all fuel hoses used for marine applications to bear the mark USCG every 12 inches, while specifying the manufacturing date.

The American Boat & Yacht Council (ABYC) recommends the Type B1 fuel hose for diesel-based applications. The Type A1 hose is the best option for gasoline supply. This hose is less permeable, highly durable, heat resistant and does not collapse under high pressure or vacuum.

Petroleum products have a huge wear and tear effect on fuel hoses. Thus, it is essential to buy high quality hoses to ensure long-term results. However, one should check fuel hoses for cracks, rot or sponginess every quarter. According to the USCG standards, fuel hoses should be wiped with a dry rag and checked for fuel odor.

Rule of Thumb
- Type A: Above Deck
- Type B: Below Deck"

Pierce

Re: Old Fuel Lines

Reply #15 – January 18, 2013, 09:05:23 am

Hi JD,
Do you have a fuel cooler? If not I would consider adding one. The hoses will hold up better without all the excess heat.

Re: Old Fuel Lines

Reply #16 – January 18, 2013, 09:16:05 am

Quote from: flite2010 – January 18, 2013, 09:05:23 am

Hi JD,
Do you have a fuel cooler? If not I would consider adding one. The hoses will hold up better without all the excess heat.

If it were the fuel return hose that was failing rather than the supply hose that could certainly be a factor, but it is the supply hose that is failing. Of course, if you are doing the labor, replace both!

That said, one of the first things I did was install a fuel cooler in the fuel return. Keep it covered with an easy to attach velcro cover in the winter and doing full cooling duties in the summer. With the diesel tank enclosed, Fortravels are more prone to high fuel temperatures than others.

Re: Old Fuel Lines

Reply #17 – January 18, 2013, 09:30:12 am

Brett,
I agree that the return hose would benefit the most. In my case fuel to the engine would get quite hot once the tank level got below 1/2. Obviously it depends whether you have been hitting it hard all day long.

Re: Old Fuel Lines

Reply #18 – January 18, 2013, 10:32:25 am

We do not have a fuel cooler. I seldom let the fuel level get below 1/2 tank. It is WAY down right now. I deferred filling because I suspected we might need to pull the tank at FOT.

I've visited with a few people with coaches built around 1997. Many have replaced fuel lines.

We replaced eight air bags yesterday. All have been looking ragged since we bought the coach in 2010. One started leaking in the last few weeks. Sixteen years of service has taken a toll on many of the rubber components.

Re: Old Fuel Lines

Reply #19 – January 18, 2013, 11:12:06 am

We changed out our coach and generator hoses about three years ago due to a leak at the tank. Found the generator supply hose fitting was loose.
I installed a fuel cooler after finding out the ECM computer used diesel for cooling while en route to the engine. Foretravel installed coolers on later models.
I started on air bags last year. Changed out the front two drivers side, which looked pretty sad. After cutting them open it was apparent that they were not in immanent danger of failing. I plan on replacing the front passenger bags in the spring.

Re: Old Fuel Lines

Reply #20 – January 18, 2013, 06:07:00 pm

Following this thread, knowing it's in the cards for us too. What is the preferred fuel line being used, rubber or nylon?

Chuck

Re: Old Fuel Lines

Reply #21 – January 18, 2013, 07:33:32 pm

This might be my follow up service this fall or maybe next year.

Re: Old Fuel Lines

Reply #22 – January 18, 2013, 08:37:09 pm

While looking for a FT, I found 1998's commonly had fuel lines that were cracking near fittings

Re: Old Fuel Lines

Reply #23 – January 18, 2013, 10:37:04 pm

I suppose I will have to look at mine in the morning, hope all iswell.
John H

Re: Old Fuel Lines

Reply #24 – January 18, 2013, 11:27:42 pm

Quote from: Chuck Pearson – January 18, 2013, 06:07:00 pm

Following this thread, knowing it's in the cards for us too. What is the preferred fuel line being used, rubber or nylon?

FOT use some kind of "plastic." On the invoice it is listed as "FUEL LINE, HTFL-8B-B" and a couple of other sizes of the same stuff. It is definitely not rubber. There is one "50 inch FUEL HOSE" that does appear to be rubber with crimped fittings on each end. I think it runs from the primary fuel filter to the secondary fuel filter. Our engine is C-8.3. Other engines are likely to use a different filter arrangement.

If you look carefully at the pictures of the fuel tank that I post earlier in this thread, you can see some of the fuel line. It is the brown tubing. Some is curled up on the floor, and some is hanging near to edge of the opening in the side of the coach. They used several new brass fittings. The new plastic hoses are attached with compression fittings.

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