47-55.1 Chasing annoying oil leaks

[TX3100Guy]

While I am waiting for some bracket material to deal with mounting some additional fan capacity for my radiator, I decided to chase some annoying oil leaks on the engine.

The first leak to be deal with was on the pushrod cover. There was a small leak (as determined by the use of UV fluid in the oil and a blacklight flashlight) coming from the back lower edge of the cover, dripping down the bell housing. The cover had been installed by the engine builder using aviation gasket sealer and it just wasn't able to fill in any minor gaps in the cast aluminum pushrod cover, so I pulled it off and using a new gasket and Ultra Black RTV sealed it up good.

The next annoying leak was coming from the oil pan gasket, this time the drivers side rear corner where the rubber gasket in the crank rear main meets the cork gasket. Again, aviation cement was used and no RTV, so I pulled the pan and have plans to put a new set of gaskets back using the same Ultra Black RTV as I used on the pushrod cover.

However, I had been also chasing an annoying drip coming from the oil pan drain plug, or so I thought. I had already put two different washers behind the drain plug and still had a drip. Not very much, a drip or two every day. Today while cleaning the oil pan prior to reinstalling, I found the culprit. The captive threaded section had split the sheet metal of the pan and I was able to see two small pin holes of light as I was cleaning it. The photos below are of the inside and outside of the oil pan after I cleaned them up.





My question is, should I attempt to seal these pin holes up with JB Weld on the inside or outside OR should I weld a small area around the captive threaded section on the inside?

[geezer#99]

Use j b weld.
Any welding might create more cracks.

[mr48chev]

My luck or lack of it runs along the line of what geezer#99 posted. That is hard spot to weld and not cause more issues than you fix.

I'd have to haul a pan over to my lifelong buddy to have him weld something like that.

[dsraven]

sometimes that stamped steel nut inside the pan can get stripped and the first thing that the parts store sells is a slightly larger pan plug that cuts it's own threads as it is screwed in. this can actually cause the split in the stamped steel part as it is not much bigger than the threaded hole already.
I have had luck in the drail plug area with brazing.
I have had a few stripped out threaded sections (that little square threaded deal that is spot welded) and some where the spot welds let go causing leaks, sometimes due to the pan being hit by something. so i have used a new, lower profile than a standard fine thread, nut brazed onto the inside of the pan and the holes/cracks were repaired with brazing at the same time. the brazing process uses less heat than a welding process because the metals are not melted together but, instead, are heated up enough so a filler metal, with a lower melting point than the base metals, can be melted into the space between the parts and around the parts. it's usually a nickel/silver filler rod or simply a flux coated bronze or brass filler rod. the area should be well cleaned and de-greased first. i usually use the torch to heat the area after cleaning to show up any oils that may find their way out when the metal gets hot. then wire brush the area on both sides before fitting the parts together and brazing.
yes, the nut is thicker than the original stamped metal nut and there will likely be a little more oil left in the pan when draining oil. I have also welded a nut onto the outside of the pan in some cases. I usually don't use a plug screwed in when doing the repair and plan to run a tap through the nut threads to ensure there is no brazing that found it's way into the threads. i also assemble the nut/plug and torque it down well with a thick flat washer under the head of the plug bolt in order to ensure there is a flat sealing surface for the new plug's sealing washer to bear down on. i have used a smaller bolt/nut/washer combo in the plug hole to keep the nut held tightly against the pan surface and also to ensure the assembly stays true to the flat sealing surface. when all done I like to polish the sealing gasket surface and check for things that may cause the new gasket to fail.
of course, the oil pan needs to come off for this process.
for the corners of the gasket area on the pan I like to use "the right stuff" sealer. put enough on to seal but not so much it squeezes out everywhere. then walk away till the next day before adding oil to the engine. i find it is the best "silicone" style sealer for this, rear axle cover pan gaskets, v8 engine intake manifold seals where there is no gasket but silicone was intended, valve cover gaskets, etc etc.
sometimes on old sheet metal, with rust pock marks etc, i will clean them to remove old paint etc, then heat them up a little and tap them with a small hammer to set up vibrations that may loosen rust from spots that will turn out to be a pin hole later. that's if I am unable to sandblast the sheet metal.

[dsraven]

since you have an actual crack and some deformed steel already, possibly due to a hit of some sort, you could try the clean and braze idea since it requires less heat. I have had decent luck using toilet cleaner to clean and degrease the area but just know it will start to surface rust right away. use a good flux covered brazing rod, if using bronze or brass, or use a good metal cleaning flux if using nickel/silver. try clamping the pan down to a solid flat surface before heating it up with brazing. you could make a wood frame and screw it down through the original screw holes.

[TX3100Guy]

Originally Posted by dsraven

since you have an actual crack and some deformed steel already, possibly due to a hit of some sort, you could try the clean and braze idea since it requires less heat. I have had decent luck using toilet cleaner to clean and degrease the area but just know it will start to surface rust right away. use a good flux covered brazing rod, if using bronze or brass, or use a good metal cleaning flux if using nickel/silver. try clamping the pan down to a solid flat surface before heating it up with brazing. you could make a wood frame and screw it down through the original screw holes.

I've never brazed, nor know anyone that does. I'll ask around though.

[geezer#99]

You could try some seal-all.
I’ve plugged 1/4 inch holes in fuel tanks with it.


https://www.homedepot.ca/product/sea...oz-/1000708738

[dsraven]

brazing is sorta like soldering with a little more heat. it's relatively easy.
if using bronze/brass you will know if it's too hot because it will fizz up and smoke a lot, like throwing water on a hot grille. try it on some scrap metal of about the same thickness first. it's pretty easy actually. it will likely leave some shiny flux on top of the brazing puddle when cool. it's just the flux component which will chip off easily.
first get the oil pan straightened out like you want it. then clean it, then you're ready.

[Rickysnickers]

My suggestion, FWIW, get a new oil pan, if there's one available.

[TX3100Guy]

Originally Posted by Rickysnickers

My suggestion, FWIW, get a new oil pan, if there's one available.

To be honest, I would love to purchase a brand new oil pan, if anyone can point me to one, I will buy it. However, in my searching all I can find is some dramatically overpriced beat up used ones on eBay.

[TX3100Guy]

Originally Posted by dsraven

brazing is sorta like soldering with a little more heat. it's relatively easy.
if using bronze/brass you will know if it's too hot because it will fizz up and smoke a lot, like throwing water on a hot grille. try it on some scrap metal of about the same thickness first. it's pretty easy actually. it will likely leave some shiny flux on top of the brazing puddle when cool. it's just the flux component which will chip off easily.
first get the oil pan straightened out like you want it. then clean it, then you're ready.

What heating sources is used for brazing. I have a propane torch and a welder at my disposal.

[mr48chev]

I'm just going to say that it takes a bit of skill and finess even when brazing it although brazing doesn't normally generate the heat that welding does.

My buddy that I mentioned before is 77 years old and still the guy certain people go to for highly critical welding that has to be at a level that is above and beyond. I don't come close to having a smidgen of the skill he has.

This shop is about 35 miles South of you in Segoville but he has the skill to do it right if he is willing to deal with something that is that small of a job. https://dirtysspeedshop.com/contact/ I've followed him on the HAMB and on FB for quite a while and at one time was seriusly thinking about having him weld me up a 32 Ford frame for a project I wanted to do that I could pick up on a road trip to visit the inlaws in Waco and McGregor.

[leegreen]

235/261 are heavy and the pans are relatively thin, they are one engine that will crush the oil pan under their own weight. That threaded plate creates a stress point right at the curve when the pan gets a bit beat up and forms a low point where water sits. My son's 261 had a nearly identical crack and slow leak after the engine spent some time blocked up while a new cross member was welded in.

I oxy/acetylene gas welded it for him. A couple rusted thin spots popped open as soon as the torch came near them. Anyone that has spent time gas or tig welding thin steel should be able to fix it. I don't think you could do it with MIG, or at least I couldn't without probably creating more leaks.

Brazing would also work, but may not be easier as the oil residue that will cook out from under the plate will mess with adhesion, and once you get it hot enough to burn that off you might as well start welding.

[TX3100Guy]

Originally Posted by leegreen

235/261 are heavy and the pans are relatively thin, they are one engine that will crush the oil pan under their own weight. That threaded plate creates a stress point right at the curve when the pan gets a bit beat up and forms a low point where water sits. My son's 261 had a nearly identical crack and slow leak after the engine spent some time blocked up while a new cross member was welded in.

I oxy/acetylene gas welded it for him. A couple rusted thin spots popped open as soon as the torch came near them. Anyone that has spent time gas or tig welding thin steel should be able to fix it. I don't think you could do it with MIG, or at least I couldn't without probably creating more leaks.

Brazing would also work, but may not be easier as the oil residue that will cook out from under the plate will mess with adhesion, and once you get it hot enough to burn that off you might as well start welding.

Thanks Lee. I ended up using a JB WEld product called Steel Stick on the inside of the pan. I guess we will see how well it does over the next few weeks.

[1project2many]

Late to the game.

If the JB weld works then you're good.

If you need to try again I recommend "silver solder." Silver solder is designed for brazing but melts at a lower temperature than brass. A propane torch is usually sufficient although I use MAPP gas (yellow tank) for additional heat. You can get a small quantity of solver solder rod and flux from Amazon for a very reasonable cost. Solver solder sticks to many materials including stainless.

Brazing materials is generally an easy process. Brazing is simply using heat to join two pieces of metal using a filler metal. For this job a torch will warm the pieces of metal sufficiently until the filler melts and flows over the metals you want to join. If you've ever soldered two wires together then you've already successfully brazed.

The key to fixing the oil pan will be cleaning the area you are brazing. You must remove all oil from a large area around the damage on both sides of the pan. Cleaning old paint, dirt, and carbon is also necessary. Once this is done you can begin brazing. Heat the brazing rod slightly and dip it in the flux. Some flux should stick to the rod immediately. Then begin heating the metal, moving the torch so as not to heat one spot to red or near red while ensuring a larger area warms up consistently. Press the brazing rod against the spot to be repaired and gently apply heat. If the rod melts and sticks to the pan you're at the right temperature. Ensure filler flows into the area you want to patch. Continue using heat to warm or maintain warming of the pan and as the rod gets used be sure to dip it back into the flux from time to time.

https://youtu.be/-LTU9vfWMFI?si=jD_AJTPp7Y4ertd2

[dsraven]

as a cleaning agent, you might try dishwasher detergent and boiling watermleft to sit in the pan for awhile, after cleaning it with solvent etc first. the metal has likely absorbed oil and will likely be releasing it when it warms up during any welding or brazing procedures, so getting it warm beforehand can help get rid of as much as possible. you could also look into getting it hot tanked a a local engine shop as well. try a friday or saturday cuz then it can sit in the hot tank for longer while the shop closes for the weekend or at least sunday, usually.

[1project2many]

A strong base will usually remove oil and leave the metal primed for brazing. Lye is one of the strongest bases, but good old Easy Off (not the low fume variety) will do wonders for cleaning. Be sure to wear protective gloves and goggles in case there's a splatter!