Oil Pump Check Ball Leak

[billpedalino]

I know that others have addressed this issue in other threads, but I thought that I would try to derive some additional information. I have just finished my '47 FL and it has the ever-common oil pump check valve leak. I've tried the more common fixes like using Ted's seat cutting tool to try to cut a new seat, I've braized an old ball onto a short spoke and lapped the seat with fine valve grinding compound, etc, etc. The oil still leaks past the ball, the lower end fills up and pumps the excess oil out of the breather when the motor starts. Other than that, it really runs great!

A while back I believe Tom Cotton suggested grinding a new seat in the pump using a grinding stone. Good idea... Has anyone done this? If so, how can the stone be (and remain) centered in the hole while grinding? I would assume that a 30 or 45 degree stone angel would be correct ?? Finally, can anyone recommend what type of tooling I should acquire to do this and from where it may be purchased? I have access to drill presses and a Bridgeport.

Any alternate ideas are always appreciated.

Thanks,
Bill Pedalino

[T. Cotten]

Bill!

I only suggested resorting to a piloted stone for roughing out damage caused by cutters, lapping, and punching.

My innovation was to burnish the seat.
And it actually works.

...Cotten

[Paps]

There may be another reason why his seat lapping didn’t seal. Lapping should have created a really good seal, especially if he gained an 80% or better cleanup on his lapping. The issue I see here, may be the lapping tool itself. Admittedly, the ball on a driver sounds like a great idea. The problem I see with this type of tool, is the way it was created. A ball bearing was welded to a driver. The welding process created a bunch of heat during the fusion of the ball bearing and the driver. The heat created by the welding procedure, softened the ball bearings outer shell. If I am correct with my assumption, the tool was actually wearing as the lapping was being done to the seat. The softened ball bearing may have mated well with the seat after lapping was completed, but was the radius changed in the seat ? One or both ,of the tools ball bearing ,or the seat surface gave way, under the lapping. The tools ball bearing, probably changed it’s shape during the lapping process. When the actual accurate check ball valve was installed into the newly lapped seat, the two radii did not mate. As I said, the tool is a great idea, but it needs to be made up without the use of welding. How does one do this ? Easy…Drill and tap the correct size ball bearing, turn and thread a driver to fit the drilled and tapped ball bearing. Lock tight the driver into the drilled and tapped ball bearing or lock nut it in, by using additional thread you put on the driver. How does one drill and tap a hardened ball bearing ? Again…. Simple enough. The correct tooling will do the job for you. Below is 3 hardened 1.0000” ball bearings I drilled and tapped. No doubt…these are larger than a check valve ball, but they are basically the same. Size is the only real difference between the check valve ball and these. Back to how I did the drilling and tapping of the ball bearings. First I needed a way to hold onto them. I wanted to utilize my lathe for the drilling and tapping work. The drawing pictured below is a general sketch of what I came up with to do the ball bearings shown. The pockets for the ball bearing in the fixture halves do not have to be a radius. I tapered mine. After I chucked up my drilling and tapping fixture into my lathe and indicated it in, set the ball bearing into the chucked half of the chucked fixtures ball bearing holding pocket, secured the fixtures end cap half to the chucked up half, I proceeded with the machine work on the ball bearing. I keep a diamond insert tip around. This diamond insert tip is what I faced the bearing off with. Diamond tips cut the ball bearings hardened surface with ease. The trick is to cut the face large enough for the tap drill size you will be using on the driver end of your new lapping tool and at the same time, accomplish getting the hardened surface out of the way for the drilling and the tapping. This can be done by opening up the faced off area just beyond the tap thread diameter and then counter boring the face below the rest of the surface hardness. Once this was completed, I drilled for the tap size. I used a carbide drill for the drilling. I then starter tapped and bottom tapped the threads into it. I used tap magic as a tapping lubricant. I also used carbide taps for this as well. The drill and taps are expensive but you get a real check ball valve lapping tool out of them when you finished. Make a bunch of them while your at it. This check ball valve lapping tool will do hundreds of laps before wearing out. You won’t have check ball valve sealing problems lapping with a tool like this.

[T. Cotten]

Lapping is futile.

And destructive, as it only widens the seat.
Narrow seats seal.

Even Clover 6-A leaves a mill profile larger than an oil molecule.

The word "burnish" means to polish.
A polished ball under pressure will polish the seat to a micro finish, and literally move metal to where it is needed for incredible concentricity.

Lapping requires total disassembly and scrupulous cleaning.
Burnishing can be done right through the oil on an installed pump, in about fifteen minutes counting R&R of the breather line..

But most of you will just hit it with a bigger hammer.

...Cotten

[Paps]

Burnishing is great but you have to have to equal radii before burnishing. Burnishing removes zero material, thus only polishing the high spots.

[koanes]

Tom, I see no reason to insult the board members here with your "bigger hammer" comment. The burnishing tool is a great idea if, as Paul suggested, you have a relatively clean surface to start with. If you have pits or scratches from pryor cleaning efforts, the seat will need to be cut. Narrow seats are better sealing, if your seat gets wide you will need to narrow it by removing metal with an end mill. Fine lapping compound should be used only to check for even pattern on the seat surface. I use Evo pushrods with 600 grit. The pushrod ends are soft and should be used once only. Keep in mind that wet sumping can also be caused by a wallowed out hole for the pump shaft in the body. A few extra thousandths there and oil will pass right thru into the return system. A late shovelhead oil seal can be fit to repair this problem.

[T. Cotten]

Burnishing is great but you have to have to equal radii before burnishing. Burnishing removes zero material, thus only polishing the high spots.

Certainly, if the seat has suffered severe punishment from a drift, or the typical chatter from a cutter, then the seat must be pre-dressed for the burnisher to work.
and that brings us back to the piloted stone mentioned earlier.

I had the best luck with a conical stone, as it quickly removes the dished portion of the previous seat negligible stock removal.
Please remember that you really want a minimal contact area between the ball and the fresh seat. Imagine a cueball dropped into one of those tall tapered beer glasses: the ball and glass touch each other at only a very fine circle around the glass. Our cast iron 'glass' will be microscopically rough because of the stone, but a ball of proper size pressed and turned with great force onto that surface will literally smooth the mill profile like a knife spreading peanut butter. Thus when a fresh ball is installed, you have two highly polished surfaces mating, and few gaps for oil to wiggle through.

I have observed an OHV sit for an entire Chicago winter and still have an overfull oiltank.

...Cotten

[T. Cotten]

Tom, I see no reason to insult the board members here with your "bigger hammer" comment. The burnishing tool is a great idea if, as Paul suggested, you have a relatively clean surface to start with. If you have pits or scratches from pryor cleaning efforts, the seat will need to be cut. Narrow seats are better sealing, if your seat gets wide you will need to narrow it by removing metal with an end mill. Fine lapping compound should be used only to check for even pattern on the seat surface. I use Evo pushrods with 600 grit. The pushrod ends are soft and should be used once only. Keep in mind that wet sumping can also be caused by a wallowed out hole for the pump shaft in the body. A few extra thousandths there and oil will pass right thru into the return system. A late shovelhead oil seal can be fit to repair this problem.

Kyle and All!

Surely you cannot be in denial that BFH mentality still pervades vintage motorcycling. Consider how many still split flywheels by beating mercilessly upon the wheels themselves.
Just like so many still rely on starter spray for finding manifold leaks, bad habits die slowly.

And don't look now, but Clover 6-A makes 600 grit look like pit run gravel, and although lapping can slow leakage, any mill profile at all still allows oil to slip through. Been there done that. (Some folks are so anal that there must not be a drop from the primary after a six week layover. Only burnishing provided such results.)

And why go to the tedious trouble to disassemble, lapp, clean, and reassemble when burnishing can be applied quickly on an installed pump? Just pull her up tight to about 15 ft/lbs a few times, toss in a new ball and your done.

And anybody with a lathe and a torch can make one.
(Just don't forget to polish out the damn ball after silver-soldering!)

....Cotten
PS: The shaft seal is indeed a useful repair, and the counterbore is easily cut on a lathe faceplate.

[bmh]

Even Clover 6-A leaves a mill profile larger than an oil molecule.

With all due respect, now we need to seal oil at the molecular level? The diameter of one molecule of oil is 0.00000833 mm approximately. That is mighty small, you can't even see that with a really good microscope. I really don't care how fancy the tool, I'm not even sure if the aerospace industry can accomplish that fine of a finish on metal. Polishing or burnishing vs. lapping and the only difference is the size of the scratches left behind, I'm sure all will be larger than the number mentioned above. So here's a question, how did they finish the seats originally? wouldn't that be the proper way to restore them?

[Paps]

Tom...don't you think my tool will burnish properly as well ? I would not use the tool I used on the lapping process. I would use another for the burnishing. The hardened ball bearing has a polished finish on it. I absolutely agree with you on the suface contact area. To deep and the angle of the radius is practically defeated. It is a must to retain the shallow angled radii for area coverage of the seal. I like you pool ball and glass example of this.

[T. Cotten]

Brian!

Yes indeed those molecules are small.
And yes indeed we have to deal with this, if our plush carpeting by the fireplace next to the bar where the machine is displayed is to stay clean.

If our machines were punished daily, or even weekly as intended, the problem would never arise.
The original designers assumed that.

But these days folks get upset when they streak the driveway after sitting just a few weeks.

I have suggested my most successful solution, and anyone can reproduce and apply it.
Except perhaps the aerospace industry.

And Pa!
Your little hip joint would would work fine if you can drive and twist it with force. By the time you have attached it to a screwpress, it might as well have been a simple 14 cent ball bearing.

...Cotten

[Paps]

It can be driven with force via a machine. The drilled and tapped hole in the bearing is on center with the bearing diameter. Note the slight counterbore in the bearings. the driver is machined to fit this spicot. The driver is chucked to the machine.

[billpedalino]

Tom,

Your burnishing tool looks great and, if you don't mind, I would like to copy it for my own use. As I have never burnished metal before, I have a couple of questions as to how to achieve the best polished finish.

Assuming that the seat is free of chatter marks, pits, etc., once the tool is screwed into the pump body, you can actually achieve the squeezing/polishing action by just screwing inner the jack screw/bearing arbor down to about 15 ft-lbs? I would also have to assume that every bit of oil must be removed first and I would most likely do a laquer thinner or acetone rinse after cleaning out all the oil. Also, if minor pitting or other imperfections are noticed in the seat, I would think that a fine stone installed on a hand arbor (similar to a manual valve lapping arbor) might be used manually to clean up the seat. This would mminimize the pressure and speed applied to the seat and would give the user the 'feel' of the stone on the seat. Has this been your experience as well?

Even though the cast Iron is so much softer than the ball bearing, I would have thought that you would have to apply significant pressure to the bearing and actually turn it a few turns under pressure to achieve the pressurized wiping action needed to burnish the cast iron seat surface to a polished finish and create the blending of materials needed create the micro-finish. I would guess that the factory may have done this in production by use of a press or similar pressurizing. But you've done this before and I would guess with good results, so apparently this repeated turning and/or higher pressure is not necessary. If all it takes is a simple screw-down, while installed in the bike, than what's better than that!

Another thought - could a high-quality epoxy be substituted for the silver solder to eliminate the possibility of ball distortion from heat? If so, does anyone have an industrial-quality epoxy product that they like? I would question JD-weld for this application but again, its mainly a compressive (and torsional) load on the bearing, so it may be suitable.

Thanks again Tom for sharing yet another inovative idea!

By the way, the leak-through of oil past the gear shaft now seems so blatantly obvious - but only after Koanes pointed it out. I didn't think of it, even after installing hundreds of Sportster and Shovelhead shaft seals. I always just assumed these seals were to prevent blead-through from the feed to return circuits. Yes folks, yet another (continued) senior moment...

Thanks to all for adding to the discussion and sharing your knowledge. After 40 years of doing this, I still learn from this forum - Such a wealth of knowledge and experience.

Thanks again to AMCA!!

Bill

[T. Cotten]

Gosh Pa,

Why even take the pump off the bike?
I prefer fast and easy, no set-up, no dial-indicating, no skill needed.

and Bill!

Just remember to put the screw through the cap before you silver-solder the ball into it's center-drilled end! The ball should be lightly clamped to assure it stays straight.

Steve at http://www.resurrectioncycle.com/ produced burnishers for both OHVs and Flatties, but I am told they must be finish-polished.
And a fellow from South Africa planned some on the HydraGlide.net forum.
(My own batch of a baker's dozen fell prey to my subcontractor's cost over-runs; I think he thought it was a government project.)

And there is certainly no need to remove the oil for the operation: I never even drain the tank.
Just install the tool quick before it overflows and makes a mess. When removed, it will purge, so re-install the new ball and spring quickly too. (If I pre-dress with the stone by hand, I let it purge at least a cup or so before applying the burnisher.)
R&R'ing the breather line is half the hassle.

A far as the pressure applied, please remember that the threads on the screwpress are an inclined plane, and the downward force is multiplied. Consider also how small the actual area of seat is. (Ideally, it could be a ring only one molecule wide!)

I am not a calculating engineer, but I'd guess it is similar force to a .25 cal slug from a two-inch barrel at thirty feet. Just better aimed.

And the torsion upon the ball snaps soft solder instantly, so any potting compound or adhesive hasn't a chance. Please remember that a ball bearing in a center-drilled screw is just like the seat we intend to dress: There is very very little surface contact between the two, and that shiny ball has no mill profile for an adhesive to cling upon.

Silver-soldering does not seem to soften the ball, but the heat does put a crust on it, so re-polishing is critical.

Good luck!


....Cotten

[Paps]

Gosh Pa,

Why even take the pump off the bike?
I prefer fast and easy, no set-up, no dial-indicating, no skill needed.

....Cotten

LOL....I was on a one track mind of the pump being off of the bike.