Water Fill Cap Stuck

[66Overlander]

Our '66 Overlander had the fresh water tank disconnected for over 20 years before we bought it. I hooked the hoses back up for the pump and tank, but cannot remove the fresh water fill cap on the front of the trailer to be able to fill the tank. According to the owners manual we need to remove this cap even to fill from the city water connection (using the bypass valve) so that the city water pressure doesn't burst the plastic tank.

So far, I have tried one of those rubber pipe wrench thaings that grab really tightly all it did was slip. I also tried tapping on the cap with a hammer in all sorts of directions and using a hair dryier to heat up the cap. None of this worked, even when doing all three almost simultaneously. Oh yeah, I also applied a little penetrating oil, too.

Since the cap and filler neck seem to be aluminum I was wondering if I could apply a torch to it to heat it up, or would that melt the aluminum or cause some other damage. I'm about to the point of removing the filler neck and cap from the trailer to be able to get better leverage by screwing the neck down to some wood.

I seem to remember seeing a previous post about this topic, but now cannot fnd them. So, does anyone have any suggestions? Thanks in advance.

Joe

[overlander64]

Greetings Joe!

Originally Posted by 66Overlander

Our '66 Overlander had the fresh water tank disconnected for over 20 years before we bought it. I hooked the hoses back up for the pump and tank, but cannot remove the fresh water fill cap on the front of the trailer to be able to fill the tank. According to the owners manual we need to remove this cap even to fill from the city water connection (using the bypass valve) so that the city water pressure doesn't burst the plastic tank.

So far, I have tried one of those rubber pipe wrench thaings that grab really tightly all it did was slip. I also tried tapping on the cap with a hammer in all sorts of directions and using a hair dryier to heat up the cap. None of this worked, even when doing all three almost simultaneously. Oh yeah, I also applied a little penetrating oil, too.

Since the cap and filler neck seem to be aluminum I was wondering if I could apply a torch to it to heat it up, or would that melt the aluminum or cause some other damage. I'm about to the point of removing the filler neck and cap from the trailer to be able to get better leverage by screwing the neck down to some wood.

I seem to remember seeing a previous post about this topic, but now cannot fnd them. So, does anyone have any suggestions? Thanks in advance.

Joe

This is a "long-shot", but it might help. If the coach was used in an area with exceptionally hard water, there may be deposits around the filler neck in the area of the threads. A treatment with white vinegar might help to dissolve any deposits enough to assist in the removal of the cap - - my thought would be to fill a "turkey baster" with the white vinegar and use it to try to force the white vinegar into the threads around the circumference of the cap - - then saturate a rag in the vinegar, wrap it around the filler covering it with plastic wrap and allow it to soak in the direct sun if possible for a few hours. This method may not help, but it shouldn't harm the surrounding finish.

Good luck in finding a solution to your water filler problem!

Kevin

[Tripp]

You may want to try the heat method again too. Carefully heat up the fill spout/cap junction with a propane torch-be extremely careful to not warp the surrounding aluminum and remove your propane tanks! Then, while the area is hot, melt candle wax into the joint and remove the heat. Let the area cool completely, then try to remove the cap. be sure not to over heat the area after you add the wax. You don't want it to burn off. And be sure to let the area cool before trying to remove the cap. That will let the metal contract as it cools and let the wax expand into the threads as it cools.

Good Luck!

Tripp

[66Overlander]

Kevin,
I doubt that it is hard water deposits as the PO says he only had the cap off once in the 28 years he owned the trailer (and I bet is was 28 years ago!). However, anything might be worth a try. We'll see next weekend.

Tripp,
Your procedure almost sounds unbeleivable, but I don't want to discount it offhand because I certainly and not an expert in the properties of wax. Is this the voice of experience or just a theory? In any case, thanks for your thoughts!

Joe

[74Argosy24MH]

Originally Posted by 66Overlander

Kevin,
Tripp,
Your procedure almost sounds unbeleivable, but I don't want to discount it offhand because I certainly and not an expert in the properties of wax. Is this the voice of experience or just a theory? In any case, thanks for your thoughts!

Joe

Wax makes a great lubricant. I worked in a metal stamping operation that used it to draw steel for awhile. There was a large coater that melted it, the flat panel was coated on both sides as it ran through rollers. They quit because the wax built up inside the dies and began to break them open.

I've used it on wood to hand form aluminum parts that need to be stretched for a deep form, works great.

John

[Tripp]

66Overlander,

The wax technique is an old hot rodders trick to remove rusted fasteners in engine blocks. Usually works without too much difficulty. I know it sounds strange, but it really does work! Doesn't matter if you use candles that smell like cookies either!

Tripp

[Creampuff]

I've got the same problem- only I have loosened the hose clamp inside and after undoing the screws the whole assembly comes out for filling.
I will try the wax trick personally and report. I have clamped my unit to a bench and tried 2 big 'mother' pipe wrenches and all I did was put a hairline crack in the neck and mess up the cap (through the duct tape).
Definitely get the thing off your trailer because torqing on it will distort the skin.

[TomW]

Joe,

I do not know if this will help, but I have attached a picture of what my '67 Overlander filler cap looks like unscrewed. To me, the wax idea sounds like a good idea, but the coarseness of the threads would keep the wax from penetrating very deep.

If nothing else, notice the "flats" that bisect the threads. If you have them, they would be a perfect spot to direct penetrating oil.

Tom

[Tripp]

Tom,

Great pic. Joe-if yours looks like this, then I too would recommend taking it off the trailer to remove the cap. I had envisioned something akin to my 56 where the cap was the "male" side. The wax could then flow with gravity.

Also, if you try the wax, give the cap a few light raps with a small hammer as it cools. I would try one of those rubber "strap" wrenches to avoid marring the cap.

Tripp

[Tripp]

Joe,

Oops, saw that you had already tried the rubber strap wrench. If you try the heat/wax method, give it another try.

Tripp

[FireFighter]

by the looks of the flats inside that cap it was made for a spanner type wrench to fit incase it gets stuck. the spanner wrench will not mar the outside.

[BobbyW]

Take 2 hammers. Place one hammer against the side of the cap and take the other hammer and strike the opposite side. Go around the cap striking it in this manner. Do this several times. This is an old plumber/pipefitters trick. Works every time for me.....an old pipefighter, er, pipefitter.

Just don't strike it hard enough to dent it.

[66Overlander]

Thanks all . . .

The picture above does look like the filler neck and cap on our trailer. I hope to have some time this weekend to take the whole thing off the trailer and try some of your suggestions. I'll let you know what worked if I have success.

Joe

[upallnight]

Originally Posted by 74Argosy24MH

Wax makes a great lubricant. I worked in a metal stamping operation that used it to draw steel for awhile. There was a large coater that melted it, the flat panel was coated on both sides as it ran through rollers. They quit because the wax built up inside the dies and began to break them open.

I've used it on wood to hand form aluminum parts that need to be stretched for a deep form, works great.

John

I've heard of wax being used to coat metal to preserve it from the elements, such as a new dutch oven or cast iron cookware, rifles and pistols way back when were coated for shipment, but I have never heard of it being used as a lubricant, doubt it penetrating capabilities.

[Creampuff]

O.K.- I finally got mine loose, but I can't confirm which technique gave me the results. I tried all the treatments including soaking the unit in brake fluid (another "old hotrodder wive's tale !)
What I did was to take out the unit, bore an angled hole (2 1/8" hole saw) in a length of 2x12, to match the angle of unit, and screwed the unit to it.
Soaking the thing , bikini waxing it, and double- hammers wouldn't budge it, even with a 14" pipewrench.

Finally , I figured I could always grind down the wrench damage as the cap has lots of meat on it, so I went for broke (literally). I rocked the pipewrench back and forth with lots of torque as I could envision the 'egg-shaping' wasn't helping. Finally it gradually broke loose and came off with the rocking motion. The cause of the seizing wasn't really evident except that there seemed to be oxidation/ calcification at the very top. I would suggest you try thr only thing I didn't which is the vinegar or CLR treatment rather than the others.

I have determined that the 'cut-outs' are there for air passage and that it is a fallacy that your tank will explode without removal of the cap.
If all this fails for you- PM me as I have been collecting replacements for this and will have a complete backup once Rob sends me the cap he promised.

[66Overlander]

Murray,
Thanks for the update and I'm glad you eventually got something to work.

I hope to take my filler neck off the trailer this weekend and then try some things throughout the next week at home to get the cap off (I'll probably try Vinegar, maybe WD40, and maybe Limeaway/CLR if I make a trip to the store). My main projects this weekend have to be to try to fix the toilet water valve (can't get a repro, so gotta figure out a way to "substitute a newer one) and check out some of the LP appliances. The cap has been relegated to a lower priority (i.e. evenings) for the moment.

Joe

[Airstream Life]

Originally Posted by Creampuff

The cause of the seizing wasn't really evident except that there seemed to be oxidation/ calcification at the very top.

I just tried to refill my water tank (68 Caravel with identical filler) this week and found the same problem. In my case, the water fill had last been used just 4 months ago, when I towed it back from Florida.

After applying some torque via a pipe wrench, I got it off. I found the same white powder in the threads, which cleans off readily. With the white powder removed, the filler cap comes off normally.

No other indications at all of what might have caused the problem. My working theory is that the snow-melting chemicals I encountered on my way back through Pennsylvanian and New York (another story) accelerated some natural process which created this white powder and locked the threads.

So you don't have to let your 60s water filler sit for 28 years to have this problem. Just one day towing through a snowstorm can do it. FYI.

[66Overlander]

Well, I didn't get to the water fill cap last weekend as planned, but I did take the filler neck off the trailer this evening. I turned it upside down and filled the cap with some old KROIL penetrating oil. I let it set about an hour, tapped it a few times with a pair of hammers (hit it with one while held against the other as suggested earlier in this thread), and then went at it with a pipe wrench on the cap and a set of vice grips on the neck.

To my surprise, I actually got the cap to turn without marring up the cap too much. The neck is fine since I grabbed it on the opposite side of the flange from the cap, so those marks won't be visible once remounted.

The specific technique I used was to set the assembly on the bench on the cap with the neck pointing straight up. I had a helper hold the pipe wrench that was gripping the cap. I positioned the pipe wrench so it grabbed the cap at the two voids so that it didn't put more pressure on the threads. I grabbed the neck with the vice grips just "above" the flange, not at the very end. I held the vice grips in one hand and held onto the neck with my other hand. It took significant effort, but basically turned on the first try. The movement was slow at first, not a typical break away.

Once off, I found the threads of the cap and neck willed with some whitish gray substance (corrosion?). I used an nail (for the pointed tip) and than a wire brush to clean out the treads and ended up with a considerable amount of whitish powder.

I'll put the neck back on tomorrow as we ran out of daylight to complete that task today. The one last thing I am considering, is making a gasket for the cap that would fit over the end of the neck and be held in place by the cap. I would think that the compression of the gasket would help hold the cap in place when traveling without having to tighten it too much. Also if the cap did become stuck again I would think that a gasket might make it earier to "brake loose" by tapping it with a hammer. What do you think?

Oh, and by the way, when the cap is "tight" on the neck there is not much air space thru the voids in the cap. If filling the tank from the "city" hookup I doubt that the air could escape fast enough to keep the tank (or some other fitting) from bursting. And even if the air could escape fast enough, I'm sure the water couldn't if you didn't turn the water off before the tank was full.

Joe

[TomW]

Originally Posted by 66Overlander

..The one last thing I am considering, is making a gasket for the cap that would fit over the end of the neck and be held in place by the cap...

Joe,

Be careful with the gasket: You noted the concern about air getting out when you fill the tank, but you also need to be concerned about letting air in when your pump empties the tank.

You may want to investigate some food-safe grease for the threads. This may retard the oxidation that seized your cap. A restaurant supply store might have what you need.

Tom

[66Overlander]

Tom,
Good point about letting air in when the pump operates. I certainly don't want to collapse the tank. I'll guess I'll scrap the gasket idea.

Joe