hekdic

Accessing in tank fuel pump from above. anybody tried?

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I've got a Gulfstream Conquest RV with 22RE engine. It needs a new fuel pump. It has a full tank of gas and I don't have any good way to drain it. I'm considering going in from the top. I asked Gulfstream what the construction was there and they said the didn't have anybody that knew how it was put together any mofe. It's open floor area up top and apparently a couple of layers before I get to the tank.

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I've got a Gulfstream Conquest RV with 22RE engine. It needs a new fuel pump. It has a full tank of gas and I don't have any good way to drain it. I'm considering going in from the top. I asked Gulfstream what the construction was there and they said the didn't have anybody that knew how it was put together any mofe. It's open floor area up top and apparently a couple of layers before I get to the tank.

For your safety go buy a siphon and drain the tank. There are wires there and I'm assuming you would cut through with power tools. Don't be careless. My neighbor blew himself up trying to work near a fuel tank that wasn't properly drained and left his wife and young children .

Linda S

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if you do try to drain, fill it with water so there aren't any fumes, the fumes make it a bomb. some have talked her about adding an electric in line unit, think it was for carberated units only. personally i wouldn't mess with a gas tank, save up and have a professional do it, less than buriel costs.

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First, absolutely, positively verify its the pump. jump Fp to B on the service connector, the pump should run.

I can give you a link to the FSM - its a big PDF (85meg) very good step by step for fuel system.

Dropping the tank isn't to big of a deal. Siphon the fuel out (as much as you can). spray the strap bolts with liquid wrench a few days ahead of time. I use a floor jack with a big flat piece of wood to hold the tank in place while I'm undoing bolts. The tank doesn't weigh a lot, don't crush the tank with the jack.

While you have the tank down, consider replacing the filler and filler vent hoses.

If I was welding on the tank, I would fill it with water, but probably not to replace the pump. Before you put the pump back in the tank, do the jumper on Fp and B, and make sure the pump runs.

John Mc

88 Dolphin 4 Auto

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ALL of the factory tanks of that era have drain plugs there is one on my 1987 DOLPHIN and my 1988 4 wd xtra cab. you can drain in to a clean spouted oil drainer drain into gas cans but be very careful.I replaced my hoses this spring with half a tank of gas. nothing came out but the fumes were horable indeed . I would only do the job outside.

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5Yoyota brings up an excellent point, WELL VENTILATED AREA. I would also add no sparks, i.e. light switches, drop lights, etc.

John Mc

88 Dolphin 4 Auto

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Thanks to everybody who replied. I measured everything carefully and laid out where the access should be to get to the pump. It was in the area where there is a table in my RV and about even with the edge of the seats on that side and was a clear area. Recon indicated that the floor had about 2 in of clear air between the top and bottom of the floor. So far so good but when I ran a stud finder over the area I got mixed messages and couldn't find a clear area that matched where I felt I should be and some locals said that the tank wouldn't be that hard to drop. Don't believe them.

I had to take a few days to meet another obligation and just got the tank out today. Not having a big lift, the room to maneuver was not much and every fitting was a yyyy to get to. In my rig the rear of the tank is almost against the rear axle housing and right up against the right frame rail. The fuel hose to to line connection was binding and clearances were such that it was a half a flat on the wrench at a time and because of access, just about all the force I could put on the wrenches. It took all afternoon just for that fitting. I've done a good bit of wrenching and that's the first flare nut that I've had that didn't come out easy once you broke it free.

Is the fuel tank and all it's garbage standard Toyota or do mfr's do different things? Do the standard pump and sending unit fit or does the 1 ton take something else?

At least I"m on the downhill slide now.

Dick

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I don't remember anyone mentioning that it wasn't a standard 17.2 gallon Toyota tank and pump.

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Thanks a lot. By the way, it was mentioned that I should drain the tank before I started from the top. It should be noted that a full tank is less dangerous than an almost empty tank. There is a certain air/fuel ratio that's required for flammability. It's possible to toss a lighted cigarette into a pail of gasoline if you're lucky. With the modern tank where any vapors are directed to the charcoal canister up front, it is due careful consideration not to pierce it but it's not the bomb that an almost empty tank is. Generally, it's a tank that hasn't been totally drained and cleaned to remove all traces of fuel that's the real problem. Then you get careless.

Dick

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My 1985 Toyota 4Runner had an access plate below the rear passenger seat. I unscrewed five bolts and I was looking at the top of the fuel tank and the assembly that holds the fuel pump in the tank.

This access made a fuel pump swap a 30 minute job. Like you, I believe it is safer to work with the tank full than with vapors.

Looking at my Toyota camper, I'm pondering about fashioning a similar hatch to make the fuel pump more accessible.

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Well I contemplated doing that but when I ran a studfinder over the area that I would need to cut, I didn't find an area below that gave clear readings so I bailed on that. Looking back on the problems I had getting the tank out, I wish I had persisted. My RV manufacturer, Gulfstream, was of no use whatsoever. In the time I"ve spent, I could have fixed whatever I had run across under there. My tank is right up against the framerail and beside the rear suspension so access is really bad. If you have a lift to get it all the way up, that would be an advantage. I understand that the flare on the fuel line expands as it is tightened to cause an interference fit with the female fitting on the hose to the tank. When you try to disconnect it, that makes it a real pain to remove. G for it! Let us know how it went.

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The fuel/air ratio is 6% to support combustion with gasoline. Why take any chances. Drain the tank. Be sure to disconnect the battery negative cable, and keep an extinguisher handy. I would never work on a tank filled with fuel. One mistake could be very bad.

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There is about 2 inches between the two layers of the floor of my RV. There is about the same amount of distance from the bottom layer of the RV to the tank. If a person measures these distances in their application, they can determine whether and how to cut the floor without touching the tank and the lines. With the tank sealed, the risk would be the same as having a can of spare gas in your garage.

With the tank full and access to the fittings and fasteners and the battery disconnected, removing the fuel pump assy would expose you to a situation with a large hole and a possibility of fire but little chance of explosion. With an empty tank full of air and gasoline vapor, any spark would much more dangerous. Without thoroughly cleaning the tank with a surfactant and water, it should be considered an extreme hazard.

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my tank has a drain bolt on the bottom; is this stock?

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The factory tank has a drain plug, replacement tanks may or may not have one

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Well, I may be extra safe while I'm more or less gutting the inside of my chinook...might drop the tank, and seeing the coach area above the tank from both the inside of the gutted coach, and the outside with the tank removed, cut myself an access panel for the future. I'm embarrased to say that i don't know if my 20R has a manual or electric fuel pump...in my 83 and all the other 22R engines I've seen, the fuel pump is mechanical, and on the side of the cylinder head. Real easy to replace. But I've hear a lot of the 20Rs have electronic pumps in the tank...so maybe that's what I've got. The chinook is very new to me, and covered with snow right now, so I haven't really gotten to know it yet.

I've fixed a mechanical fuel pump on the side of the road in the middle of nowhere southern Utah. I don't think I could do the same with an in-tank, electronic pump...

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The fuel injected 22RE which I have has an electric fuel pump. If I'm not mistaken the 22R is mechanical.

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My 1978 20R has the electric tank pump. Easy way to check is follow the fuel line from the carb back. If you don't find a mech pump attached to the block,your electric.

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My 1978 20R has the electric tank pump. Easy way to check is follow the fuel line from the carb back. If you don't find a mech pump attached to the block,your electric.

My 1978 Chinook also must have an electric pump in the tank although I can't say I've seen it yet. There is no mechanical pump on the engine and no electric pump along the frame so I guess it MUST be inside the tank.

I am going to eliminate mine and install an external HD electric fuel pump. Not needed - but I don't like the idea of a fuel pump I can't get to while on the road somewhere.

In regard to worries about accessing from top and possible exlosions? Gas in liquid isn't explosive -just the fumes are. You can throw a lit match into a bucket of gas and the match will go out (not recommending it -hard to avoid the fumes on top).

Cutting in from the top is no big deal if you don't mind messing up the floor area. Just avoid sparks and make sure you smell NO gas fumes in the working area.

I've had to do to countless American cars. Many Japanese cars already have cute littl access holes over the tank.

Most electric fuel pumps do not draw fuel very well. They are mostly designed for pushing fuel. That's why the best place for most is at the bottom of a gas tank.

Walbro makes a plunger-type heavy-duty fuel pump that IS rated to draw fuel up to four feet and has a contiuous service life of 18,000 hours (720,000 miles).It's the FRB series. I use them in all my equipment when possible. NOT possible with gas fuel injection though. Just carbed or electric-carbed engines. And yes - overkill maybe on a little Toyota. But I've had to fix a lot of dead rigs with failed electric pumps. In a motorhome it can be even more of a problem. You are often far from home with few tools and sometimes in the middle of nowhere when something stops working. Subsequently I prefer an external pump, be it mechanical or external. If putting an external pump that draws gas from the top of a tank though, only certain types are reliable.

In a Toyota - an FRB Walbro mounted outside the tank will work fine and should greatly outlast any Toyota truck. The Walbro FRB-20 is the one for a carbed engine or mechanically injected diesel. Makes 2-4 PSI of fuel pressure and flows a max of 33 gallons per hour.

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Yeah, I hate the idea of something so simple, which can so easily fail, being so hard to get at...

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I'm thinking of putting a 2nd gas tank in my 78 Chinook. Great spot for one where the spare tire was originally. Another reason for me to use the external electric fuel pump. Easy to rig up dual fuel tanks.

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could you still trust your gas gauge? would one tank fill the primary until it was empty then the primary goes down; in effect the gas gauge would just stay on "F" longer?

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could you still trust your gas gauge? would one tank fill the primary until it was empty then the primary goes down; in effect the gas gauge would just stay on "F" longer?

I would put a sending unit in the second tank with the same variable resistance as the original. A tank fuel-level sending unit is just a generic variable resistor. You just have to know which range any particular truck uses. Old Toyotas have sending units that work pretty much the same as Jeeps, Fords and Chryslers built before 1986.. Then install a dual-tank diverter solenoid. It is standard equipment on many trucks including my Ford pickup and Chevy pickup. My Dodge truck also has one that is aftermarket from Aero Tanks in California. You have a switch on the dashboard that reads "tank A an tank B." When you flip from one to the other - the gauge in the dash reads from whatever tank is selected and the solenoid diverts the proper gas tank to the engine. My Dodge diesel pickup has a 30 gallon tank in front and a 55 gallon tank in back. It really hurts the wallet to fill both when empty. Ford trucks usually come standard with dual 19 gallon tanks. With this Toyota -there's a lot of room to stick a square Jeep tank in where the spare normally goes. A Jeep CJ3 or CJ5 tank is 25" x 18 1/2" x 6" . A Ford rear truck tank might also fit although I haven't checked yet. A square Ford rear tank is 34-3/4" x 27" x 7-7/8" and holds 19 gallons. The bigger Ford square tank is 34-3/4" x 27" x 13-3/4" and holds 38 gallons.

There may be better choices but I just happen to have one sitting in my shop and it looks perfect for the job. A second fuel gauge could also be added if matching the Toyota gauge was a problem.

A standard Jeep CJ series fuel tank sending using works with 10 ohms resistance when full and 73 ohms resistance when empty just like many Fords.

Other makes :

0 ohms empty-30 ohms full (GM Type '64 and earlier)

0 ohms empty-90 ohms full (GM Type '66 and later)

75 ohms empty-10 ohms full (Ford and Chrysler Type '86 and earlier)

16 ohms empty-158 ohms full (Ford Type '87 and later)

90 ohms empty-0 ohms full (Toyota and Nissan '85 and later)

240 ohms empty-33 ohms full (Standard Aftermarket like Stewart Warner)

10 ohms empty - 180 ohms full (VDO gauges)

A 1978 Toyota pickup uses a fuel level sender that works as thus: Full - 3 ohms, 1/2 full - 33 ohms, empty - 100 ohms.

http://www.mtscompany.com/jeep.htm

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My 77 chinook actually came with an access hole cut by A previous owner who was apparently unwilling to drop the fuel tank. Yesterday the fuel pump "finally" got replaced by a couple of good friends who also trouble shot the fuel gauge sending unit that wound up having a hairline crack in a soldered electrical connection. The nook runs on it's own now and as far as we can tell the gauge is reading properly. One thing that bothered me a bit was in the kit for the fuel pump the top of tank gasket was too small, it fit on the inside of the screws not lined up with them. It seems to have sealed well though. The other thing was what to me looked like a "T" fitting above the pump that was a pressure relief valve that was stuck closed. My buddy managed to get it unstuck and working dependably with a hand operated vacuum device though. I think that valve being stuck was why I found 2 dead fuel pumps in the box of old parts as well as why the one I had in the tank when I bought the nook was bad.

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