Hi all,

All of the recent posts having to do with fires has made an impression on me.

I haven't posted anything lately because the 28 foot, 1981 Barth Euro, with a Quadrojet on top of the Chevy 454 has been out of use. I plan to go through it from top to bottom, in and out before I take it out again. One of the first things I want to address is the fuel supply system.

The original owner removed the two original fuel tanks and replaced them with a single 80 gallon tank with an electric fuel pump. The new fuel tank is in the rear of the coach, below the bed, between the frame rails. In the process he abandoned the original steel fuel lines and installed rubber fuel and return lines from the rear of the coach to the engine. I plan to either reconnect to the original steel lines or replace them with new metal lines.

Near the carb is a fuel filter looking thing which the return line connects to. Is there a replacement for this that has threaded ends that I can connect metal lines to? I was also wondering if this thing could be located in the rear, near the gas tank rather than up front near the carb?


Barry

I think I'd stick with flexible fuel lines. I replaced the carb filter on my SOB (Chebby 5.7L, Rochester Quadro-jet), and even though I backed the flare nut, the fuel line split when I loosened it. The was a stripe of rust along the split, which was almost an inch long. I replaced it with double-clamped fuel injection hose.

The supply hose is subjected only to low pressure, around 8 psi. Rubber hoses will generally give clues if they're deteriorating. Rust and metal fatigue on a steel hose might not.

Danny Z might know about the return line thingie...I surely don't.

quote:

Originally posted by Barry:
Hi all,

Hi, Barry, How ya been? Mmissed you both at Q. Still got the Pinzgauer? Went out with one at Q, and he showed me up big time.

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I plan to either reconnect to the original steel lines or replace them with new metal lines.

Good plan. The less rubber you have, the fewer problems can develop with age. Some racing associations have a limit of how much rubber fuel line you can use, for safety reasons. It is just a few inches, total, as I recall. I remember some tech inspectors flagging rubber fuel line anywhere in the engine compartment except way down low, between the frame and fuel pump.

New steel lines remove any worry about age-related problems. While you are at it, run the new lines outboard the frame rails to keep them cool. Chev had an SB on that.

quote:

Near the carb is a fuel filter looking thing which the return line connects to. Is there a replacement for this that has threaded ends that I can connect metal lines to?

Dare I say it.............A picture is worth a thousand words. It could be a filter with an orifice to allow a certain amount of fuel to go back to the tank as a vapor lock mitigation. Is there a filter down low on the right side near the fuel pump?

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I was also wondering if this thing could be located in the rear, near the gas tank rather than up front near the carb?

The return line helps keep cool fuel moving through the main feed line to avoid vapor lock. It can also remove bubbles. Moving the thing rearward would compromise this.

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Originally posted by Rusty:
I replaced the carb filter on my SOB (Chebby 5.7L, Rochester Quadro-jet), and even though I backed the flare nut, the fuel line split when I loosened it. The was a stripe of rust along the split, which was almost an inch long.

That is common on Q jets with a history. Unless every previous mechanic uses the correct wrenches and torque, work-hardening can develop, and a split is often the result. The split usually occurs along the line formed when the line is made. The classic Number One is backing off the flare nut with an open-end wrench without holding the filter nut with another wrench. Number Two is overtorquing the flare nut, again with an open end wrench. The distortion induced by the open end wrench requires overtorquing to eliminate leaking.

I cut off a few inches and use a compression union to put in a piece of new metal line with a factory double flare and a new flare nut.

Also, overtorquing and dry assembly can result in galled and/or seized threads on the filter nut on a Q jet. Anyone with a Q jet should remove the filter nut and reassemble with anti-seize or black Permatex, just to avoid trouble at an inconvenient time and/or place.

Well, there you go again, suggesting that mechs: a. Exercise care, and b. Exercise care.

One of the reasons I endorse robust flex line is that they're more mech-forgiving - and also more user-forgiving. Since fuel lines tend to be grossly neglected, the flex lines are, IMHO, more forgiving of neglect/improper maintenance.

As for me, I don't know what "black Permatex" is, but I keep a robust supply of Permatex #2A on hand. (Just used some today on my house water tank bleeder valve). I also keep P #1A on hand, too...as well as the aircraft-quality sealer.

quote:

Originally posted by Rusty:
As for me, I don't know what "black Permatex" is, but I keep a robust supply of Permatex #2A on hand. (Just used some today on my house water tank bleeder valve).

Yup, that's the stuff. It seems more resistant to gasoline and axle lube than others. http://www.permatex.com/products/Automotive/automotive_...ket_No_2_Sealant.htm

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I also keep P #1A on hand, too...as well as the aircraft-quality sealer.

Where do you use it? I'm afraid of it. In high school I had a bad experience with it's permanency. I owned a Harley that had the heads sealed with it in WWII, owing to a war shortage of gaskets. The heads never did come off.

I can't recall the last time I used #1 or 1A. I think it was on a radiator tank with a pinhole leak - I inserted a screw with #1 on it...25 years ago.

Hello Bill
How are you doing?
Sealer thread drift add-on follows.
On our way back from Az this April I stopped in to Carlsbad NM. and bought a 1965 Royal Enfield Interceptor 750 vertical twin. It had sat in dry storage since 93 or before. Somebody had sealed the primary chaincase with balck permatex or similar instead of fitting a new rubber seal. Had to us a paint stripping heat gun for about 2 hours to get that case off! This was the stuff that hardens up and if it has its place but this was NOT it.
We just flew back from a week in Phoenix and while there visited a couple of prospective RV parks for this winter. AND hopefully will make it to Q this year. We are saving our money for diesel now so we both really miss not getting out in the Barth.
Hope to see you at Q.
Don and Patty

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Originally posted by bill h:

quote:

I also keep P #1A on hand, too...as well as the aircraft-quality sealer.

Where do you use it? I'm afraid of it. In high school I had a bad experience with it's permanency. I owned a Harley that had the heads sealed with it in WWII, owing to a war shortage of gaskets. The heads never did come off.

quote:

Originally posted by Don in Niagara:
Somebody had sealed the primary chaincase with balck permatex or similar instead of fitting a new rubber seal. Had to us a paint stripping heat gun for about 2 hours to get that case off! This was the stuff that hardens up and if it has its place but this was NOT it.

A trained Enfield mechanic would have only used the sealant on the bottom half, since this is where the leaks form, and leaving the top half without sealant makes it way easier for the next guy to remove it.

Hi All,

Thanks for your replies. It's too hot to spend much time working on the Barth this time of the year out here in Phoenix, but I am trying to put together a To Do List.

Bill H, Jacque and I missed you all at the Q this year, but are hoping to be able to make it in 2009.

I will post my Barth Tag info as soon as I can bear to uncover the Barth and get inside.

Barry

Hey Barry, good to hear you're still around. How about getting on the "map the Barth's" so I'm not the only lonely Euro on the whole map? Are you sure the "fuel filter looking thing" isn't the mechanical pump? It's on the passenger side lower forward mounted directly to the block. One line in, one out to the rear, and one out to the carb. I just replaced the pump and all the rubber and clamps. Took care of 95% of the cutting out, but I still get little hick-ups when I run her long and hard.

Hi Danny,

My fuel system no longer has a mechanical pump. When the previous owner eliminated the original fuel tanks and replaced them with one 80 gallon custom tank he also eliminated the mechanical pump and replaced it with an electrical pump. I have not dropped the fuel tank so I don't know if the pump is inside or outside of the tank.

The part that I am referring to looks like a fuel filter except that it has three lines . One line from the tank, one to the carb and the other I believe is a return line back to the fuel tank.

My 1984 Jeep Scrambler had the same part that was used for fuel return to the gas tank. If it is not part of the original fuel system, it may have been added to prevent over presurization of the Quadro Jet carb now that the system is fitted with an electrical fuel pump.

My intent is to try to eliminate rubber fuel lines as much as possible, especially in the engine compartment.

I will put all my info on the site as soon as I get into the Barth and get my data tag info.

Thanks,

Barry

quote:

Originally posted by Barry:
The part that I am referring to looks like a fuel filter except that it has three lines . One line from the tank, one to the carb and the other I believe is a return line back to the fuel tank.

My 1984 Jeep Scrambler had the same part that was used for fuel return to the gas tank. If it is not part of the original fuel system, it may have been added to prevent over presurization of the Quadro Jet carb now that the system is fitted with an electrical fuel pump.

Without a picture or a part number, it does sound like it is a filter with a vapor return. They don't really drop the pressure much, if at all, because the return passes through a small orifice, but it keeps fuel running through the lines faster to avoid heat build up and vapor lock. It also avoids vapor lock by preventing vapor build up if any does form. With that and the elec pump, it sounds like it had a good hot-weather mechanic at some time in its life. Does it have a part number on it?

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My intent is to try to eliminate rubber fuel lines as much as possible, especially in the engine compartment.

Good idea. Using as little rubber line as possible anywhere is good, especially in the engine compartment of a motor home. I use Goodyear or Gates fuel injection line and change it yearly. It's cheap and easy, and fires are neither.

NOTE: much hose and plug wire aging and hardening in the engine compartment is not the result of operating conditions, but heat soak after the engine is stopped and, of course, air flow has stopped. A thermostat-controlled big sucker fan takes care of that. Search for an earlier post on that.