...is it to clean out a side fuel tank?

I have an '84 F150 XLT, 351 HO (Holley 4bbl) 4x4, with dual tanks, but only one is operational right now, that being the front (side) tank. I am almost positive the sending unit needs replacing, but I am pretty sure there is gunk in the tank as well. She is almost empty right now, so I am thinking about dropping the tank this weekend to replace the unit and try to clean the tank. I have never done this before, so I need some advice on what, exactly, to do here. I assumed some fresh gas to slosh around and try to "wash" out the trash is in order, but is there anythign else needed to clean it out? Is there something else I need to do or would that be the best way to take care of it?

Or, am I pissing in the wind here? Is replacing the tank the only real option? I hope not, because it seems to be in good shape, but after years of sitting, this old girl has some things that need attention. Next up is a carb rebuild/replacement. She is in REAL bad shape, so I don't know if rebuilding is even an option, but I KNOW the tank issues have to be addressed before I take care of the carb issues.

Thanks in advance!

 

I have cleaned a tank in the same manner that you have planned to do.
I was able to get the rust particles and varnish out by "sloshing" clean gas around for a while. I can't remember if I used a brush to aid in the cleaning.
It worked well and I did not have any problems after that.

As far as your carb goes - a new one maybe a quick fix (but expensive) and rebuilding is generally more "fun" to do, but will take some time.

If you have more cash then time...............you know.

 

I usually use a few bottles of the in tank carb cleaner to slosh around, I figure it's a little more potent. I have also used a pressure washer to blast the inside of a tank. I just made sure to drain as much water as I could and let it sit in the sun for awhile. I also used a bottle of the water remover after I had it back together.

 

Thanks for the replies. This is kinda what I figured, but I hadn't thought to use the in-tank cleaner. If it has a lot of crap in it, I may wash it out good with a pressure washer or garden hose and let it sit in the sun for a while. Since we have had almost 100 degree temps and no chance of rain, it probably won't take long to dry out!

As for the carb, I have NEVER had more money that, well, ANYTHING, so i don't know what I will do just yet. Carb wasn't in too bad of shape until the BIL was trying to start it a couple of years ago with starter fluid and it caught on fire. He had to douse it with a fire extinguisher and it really messed things up. it runs, but has a lot of crap built up in places, so I am not sure a rebuild/cleaning would even be worth it. I actually can't even tell which carb I have because the numbers on the front have been worn away and have crud all over it.

Anyway, if I can get the tank issues fixed, that will go a long way towards getting her running like I want her to.

One more question - When she sits for a while, she is hard to start again. More than a week of sitting is almost impossible. It is like all fuel drains back into the tank and it takes forever to get back up top. I wondered if the sending unit and crud in the tank issues would cause this? If the sending unit is bad, will it allow fuel to drain back into the tank, essentially draining the lines? I suspect the crud is also settling back to the bottom of the tank, causing the line to clog when it is trying to get gas back as well. Am I correct in my thinking here?

 

If your bowel vent line on top of the carb is disconnected, then the fuel evaporates out of the carb when it sits a long time. I had this same problem on my 1980.

 

You could also drop a clean piece of thick chain in there and shake or roll the hell out of it.

The chain helps break up any crud that's stuck inside.

 

Check the fuel tank selector unit real well, they can cause lots of problems if even marginally bad. I've replaced mine do to one tank not leaking, draining into a leaking one. Just flowed right to the lowest tank. A selector internally leak could cause hard starting if it allows air to be sucked toward the manual fuel pump instead of fuel. Also, contaminated fuel from unused tank can cause bad behavior. Check for a accelerator pump shot before you start by looking down the throat of the carb and actuating the accelerator. It should be obvious and strong if fuel is present in the carb. If its not ,check again after you get it running and shut it down. Then you will know fuel is present in the carb. If still no pump shot rebuild the card.
It sound as if you may have many marginal parts of the equation working against you. Check after running and shut down to see if you have a strong fuel pump pulse as well. A bad, or on its way manual pump can operate weak for a long time. Yes to your question about fuel retracting back away from the engine causing hard starting, but this usually requires a bad pump.

 

I've used paint thinner instead of gas. It seemed to work better and quicker. My very unscientific experiment (N=2) has found that paint thinner made specifically for oil based paints worked even faster.

Be careful if you put any metal in the tank and shake it - an empty gas tank is much more dangerous than a full one.

Have you thought about using a gas tank sealer? It's a sort of liquid plastic that you pour in there and let dry. Start the process early in the day and keep turning it occasionally to thicken up evenly on the base, walls and ceiling. I did that on an old Ford 8n not long ago and was quite pleased with the results.

Best of luck.

 

I'd clean and put a kit in the 4180C carburetor if nothing is melted from the fire. It's not that difficult if you follow the instructions exactly. It is imperative that you have a good compressed air source to blow out the passages. I quit soaking carburetors in cleaner years ago. Now I use spray cans of cleaner and fill all the internal passages with cleaner, let it sit for awhile, blow it out and repeat two more times. I don't even remove the mixture screws, just make sure cleaner fills the passages to them and soaks well. If the power valve is bad, be sure to replace with the correct one for your particular carburetor. Beware of kits that include a power valve, it's a one size fits all type that may or may not be right for your application. Make sure to use the proper power valve gasket, it's the one with 3 inward pointing "prongs" for the two-stage valve. I've had excellent results with Holley and Walker brand kits. Be very careful with the fuel inlet fitting, it's easy to cross-thread and damage the float bowl. The float setting is fairly critical on these carburetors.

 

Thanks guys! Lots of good information here!

I bypassed the tank slector switch because the rear tank was contaminated years ago. Some jerkoff pured tar in the tank when the previous owner had it. Luckily, he saw the remnants on the fender before switching to the rear tank. Idiots apparently never saw that it had two tanks, so that was a good thing!

Anyway, the carb is in pretty rough shape to look at it, but when the line isn't clogged, she actually runs pretty well. I have done some cleaning with a small copper wire brush and the shop-vac to make sure no loose material dropped into the carb, but I am pretty sure it will at least need a rebuild. Like I said, the numbers are buggered up, so I am not 100% sure it is a 4180, as the engine was rebuilt once and they could have put a different Holley carb on there. I KNOW it is a Holley, just not 100% sure which one.

I may just opt to replace it with a rebuilt one and be done with it. This old girl has had more "rigging" done to her than any vehicle I have ever seen. She even has an inline lawnmower fuel filter! But, it works!

Anyway, thanks for the advice and I will hopefully drop that tank this weekend and start cleaning her out.

Any idea on where to buy a good rebuilt Holley carb without having to sell a kidney?

 

If there are no leaks and it "runs pretty well" why do anything to it? You might want to replace the inlet fuel filter (if its still there) on general principles.

 

Well, here's the biggest reason why (disregard the arrows and numbers):



If you will notice where the fuel line comes in (right under the 04), there is no screw-in filter. The filter is actually a lawnmower filter in that flexible line just south of the bottom of the picture. All info I can find on the 4180 carb says the fuel filter should screw into the carb where the line comes in, but mine doesn't. Since the numbers on the front of the carb are worn and I can't make them out, I am not 100% sure which carb I have, so I figured with the state it is in (and you can't even see down in the thing where the buildup is bad) and since I am not 100% sure which one I have, replacing with a good rebuilt carb might be the best option.

I am not above rebuilding it myself, but I don't want to spend a month just trying to figure out which kit I need. But, who knows, it may be best to pull the thing and see what I can do with it!

 

Herre's another one from an old post I made about this very subject (sorry to those who chimed in back then, but I haven't had time to work on it and knew I needed to fix the tank issue first!)



BTW - Yes, all of the pine needles and other crap have been cleaned off! Actually, she is pretty clean now, aside from the crud from the bath with the extinguisher!

In this pic, you can see the fuel filter. I believe someone in an old thread told me this looked like the old Ford/Holley carb, but the carb not having a place to put a screw-in filter stumped them. Truthfully, it has stumped me as well!

But, the tank issues are first and foremost. I may opt to replace/rebuild the carb soon now that the gubmint is giving me back some of my own money!

 

From the style of the float bowl it looks like you may have a "Truck Avenger" carburetor. If it is, it's a "keeper". If you can find the List # contact Holley Technical Support on-line. They can tell you what it is and the correct repair kit number.

 

Looks like another Ford carb built by Holley. Pretty nasty though. The built in filter people are referring to may be the simple mesh screen that is usually located behind the banjo fitting at the fuel inlet. Sometimes people just remove them though. Your carb looks similar to the one I removed from my truck except mine had a vent hose on the front and back of the carb.