Shellac used for sealing hydraulic pumps

I just had my 70 L.P. power steering pump overhauled by a very reputable hydraulic shop; I asked them where did they get the "shellac" to seal the pump with, which is mentioned in the Deere shop manual. They looked at me with a blank stare and said "It doesn't need anything to seal it with, the metal surfaces are super smooth..." The local Deere dealer said about the same thing. So what gives? Has anybody had a power steering pump for a 2 cylinder Deere tractor rebuilt recently, and did they use the "shellac" that is mentioned in the shop manual? I haven't used the pump yet, but it appears that it might be leaking without even starting the engine. Anybody have experience with this? Thanks, Hugh
 
Hugh,

The manual does say to apply a thin coat of shellac to the mating pump surfaces as you know. I think I recall FIT saying he simply applied a thin coat of oil after lapping those pump surfaces. I would be more concerned about the shaft , bushings, and oil seals when it comes to pump leaks. I had my JD dealer replace the seals in my 80 PS pump, still leaks.
 
I never used anything on them but haven't done one for years.
There is a product by Loctite or Permatex in a little tube.
It's called anerobic something. The complete name escapes me right now.
Use it sparingly so as not to squeeze it into the pump.
Maybe it's anerobic gasket maker????
 
A THIN bead of anaerobic all the way around the face of each section, on the OIL side of all the bolt holes will do the trick.

<img src = "http://images.drillspot.com/pimages/7768/776876_300.jpg">
 
I put new seals in the power steering pump on my 630 in 1976. Tractor had been in a fire. I bought a can of shellac at the local hardware store, painted it on the mating surfaces, and bolted it together. Hey - shellac is shellac, isn't it? It's what the service manual said to use, ha. It would have worked good, except I put one of the seals in backward, and you can guess the results. It's been leak free for a long time (after I put the seals in right).
 

Hugh,

I've rebuilt 4 or 5. I always use a thin coat of Permatex Aviation. It's a liquid with a brush cap. I don't like using anything thicker, because I don't want to increase the clearance between the gears and the end plates. I've never had a pump leak yet...
Permatex also makes a similar product called Aviation Super 300. Works just as well. Actually I always meant to look up the site to see what the difference is...
OK, after a little google work, it looks like the Super 300 has a slight edge. I've used both. I do recommend getting the smaller container, as the brush in the cap tends to get wobbly in the bigger container.

Adrian
 
The manual might be referring to Indian Head Gasket Shellac which is still available from NAPA and others..
 
I rebuilt them for years at a JD dealership. only used a light film of grease so the plates could move while torqueing the bolts .
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top