Leimbach pump tip

[steamer]

When you first purchase a new Leimbach pump they look like this.

The oval hole closest to the motor is just to tighten the drive coupling to the motor shaft and the set screw next to it, is to fasten the motor to the pump.
We all know that after long usage the pump shaft seals begin to leak and the oil can carry over to the motor with this result.

Sorry for the quality of the picture but i think you can see that the brush holder is just a big gob of gooey oil and carbon dust. It took an hour to take the motor apart and clean it out and reassemble it,
The reason I have shown the first picture is if you loosen the setscrew and turn the motor one half turn now you have a place for the leaking oil to drain out of and it will not carry on to the motor

This motor was so bad that there was 3/4 of an amp leaking to the case of the motor and it was a smoke show and it would get so hot you couldn't even touch it. After it was cleaned it runs as cool as ever.
Rob

[SmallHaul]

Great info Rob!

I am working on a Wedico loader now that has a leimbach pump and a fluid soaked motor. I flushed the motor out with non-flamable CRC cleaner and that worked great but, after running it for an hour I could tell that a small amount of oil got into the motor again.

So, I will flip the motor over so that the oil can drain without going into the motor but, can I change the seals so that won't leak any more or won't that help?

[iaindunn]

I believe they use standard o rings as shaft seals. They are not particularly good and I have the same problem on my diy pumps. I changed to proper shaft seals and have not had a problem since. They will wear of course but are better designed for the job. I think the Leimbach has a small shaft 3mm? so finding seals for this size might be difficult. Lots of people also crank up the pressure and this is the result as well.

Iain

[steamer]

Thanks Scott. Yes you can change the seals but it's quite a job too. The seals are in the motor side of the pump and are held in with what I would call a seal head. If you separate the motor and pump you'll find that you can just pull the drive coupling and pump shaft out in one piece. It's okay to do this as the shaft has a flat spot and the pump gear has been staked to fit the shaft. Be careful as there are shim washers behind the coupling you don't want to loose. In the centre if you look close you'll see the outline of the head and it's held in with four center punch pops. Now the tricky part, you have to drill out the punch marks to free up the head. I used a 1/16" drill bit down about .040. Next about 1/8" outside the shaft hole dill two more holes 1/16" down about .080 to .100 thou. In there use two 1/16 roll pins and drive them in. With wide mouth pliers gently turn the head to breaks the punch marks and when it turns, slowly begin to back he head out. Once out you'll find Three o-rings, two on the head, one in the body.. The reason they leak is they used a butle ring and they won't take the temperature. I used a Viton and they should will last longer but we''ll see. I have the sizes for all three if you need them.
Rob

[SmallHaul]

Thanks for the detailed description, it sounds like quite a job to do. I flipped the housing over tonight so the vent hole is facing down and I'll run it a lot tomorrow and see how much it leaks. I ran it for about 15 minutes and it looks bone dry so maybe the leak is very slow.

[doodlebug]

Have you guy's looked in the http://www.simritna.com/ for micro seal's?
Somebody on the German forum use's them for cylinder seal's.
Later, Neil#2 aka doodlebug.