Help on B pto shaft leak

JOCCO

Well-known Member
Late b 1950 I have had a leak on the pto shaft into the transmission, where it goes through the rockshaft housing. So I put another pump on and same issue. Yes there was the brass washer, spring and seal. Any help here thanks
 

JOCCO,

I have the same problem with my 1948 Model B. Everything worked just fine for the first 3 years after I restored it, then it started leaking back into the differential. I replaced the Bearing, oil seal and the 2 packing seals that go inside the cup, oil seal but still had a leak. Started costing a bunch on oil.

I was looking for an old timer that could tell me how the oil is really suppose to be kept separate in these tractors, with no response. Suggestions, yes, but nothing about how it is suppose to work.

After looking at the whole system, I figure that the B2626R bushing in the B2798R housing is warn along with the PTO shaft enough to allow the oil to flow into the differential. Also, it is the only thing left to change on my tractor.

I ordered a bushing and when it comes in, I will have to have my PTO shaft welded up and turned down to fit, because there seem to be no more PTO shafts available.

Yes, at this point, this is another guess.

I also, welcome any cheaper suggestions.

I'll keep you posted.
 
The seal is a face type seal, two flat brass faces held together with spring pressure. The
surfaces can't have any sort of nick or scratch in them. This type of seal is also used in
bulldozer track rollers and front idlers. Water pumps seals use porcelain faces.
 
(quoted from post at 08:54:14 05/12/19) The seal is a face type seal, two flat brass faces held together with spring pressure. The
surfaces can't have any sort of nick or scratch in them. This type of seal is also used in
bulldozer track rollers and front idlers. Water pumps seals use porcelain faces.

Yes, where the cup and the bushing match up, it is highly polished where they rub together, however, it still leaked even after I replaced the 2 rubber seals inside the cup.

Just how much tension is the spring suppose to have? Could it be the spring is not pressing hard enough against the cup assembly? When I put in the 2 new seals, things fit tight but the pump oil leaked out even faster.

Just asking.
 
(quoted from post at 06:18:09 05/13/19) How was the brass seat that is pressed into the housing?

The brass seat in the housing was highly polished, the same as the cup that presses against it. No groves or scuffs.

This tells me the cup and the 2 rubber seals ride on the PTO shaft and turn with it. The 2 rubber seals don't really seal but act like a break so the cup turns with the PTO shaft. Just the way I see it.

If there is no turning, like when the PTO is turned off or the tractor is parked, any pressure in the hydraulic system, even gravity, will leak back into the differential if that spring is not strong enough to press the cup against the brass seat. Again, how much pressure from the spring is really needed when new rubber seals are put in the cup?
 
If the seal surfaces are good and the packing's are new then the spring is weak or there is a crack in the housing someplace. The packing's provide a static seal so I doubt there's much problem there.
 
(quoted from post at 11:08:49 05/13/19) If the seal surfaces are good and the packing's are new then the spring is weak or there is a crack in the housing someplace. The packing's provide a static seal so I doubt there's much problem there.

Yes, I was thinking that! I can't see anything written down but it makes since. The spring must be able to push the cup and the packing against the bushing face and hold it their, just in case there is some in out play in the PTO. Even a 1/32" play would be enough for the hydraulic oil to pass through if there is any ware in the PTO.

I put in new packing. They were tighter than what the spring could force against the bearing. Doesn't take much.
 

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