D4 hydraulic pump repair

The usual design on something like that would have an o-ring or other packing next to the bearing beside the high pressure chamber and then a drain off back into the suction channel inside of the external oil seal. This keeps the oil seal from getting much pressure, but it does have to hold the static head pressure of the oil in the reservoir. If internal seal is bad or bushings are worn, the external seal may get blown.

Probably just a plain ol lip type seal. Good luck finding info on that orphan pump.

Probably just a plain ol lip type seal. Good luck finding info on that orphan pump.

I would think a 3 part seal with a spring and a bushing with a square rubber ring inside like what is used in a Bee Gee pump could be adapted .Associated tractor in Stockton has had the original style seals for Bee Gee pumps,but very pricey compared to the lip seal . I have used lip seals in several pumps,for different reasons they didn't stay around long term so I will not guess how long they will last .

Thankyou guys for chiming in, I've been looking at Google the past 24 hours trying to find some info on Armstrong Holland pumps without success, I've added some photo's I took yesterday showing the conventional lip seal someone had fitted previously and you might be able to see the crack in the lip, I'm assuming a special high pressure seal should have been used there, or even a double stack of seals, that is why I was interested in seeing the original seal design because it would have been leather wouldn't it, from 1941?

In the second photo you will see a large locking nut sitting in behind a bearing, that nut has come loose and was probably rattling around in there, other than that the bearings look OK to me and the shaft is snug in that bronze housing, but controlling the pressure in that drive shaft tunnel back towards the transmission is what is concerning me because as Jim says there might be a O ring or similar seal helping a conventional lip type seal, and in just an hour running the tractor for the first time it pumped about 4 gallons of 30W oil back into the tractors transmission.
Thanks again
Mike

Mike, a Google search brought up this thread from Red Power http://www.redpowermagazine.com/forums/topic/61424-td-14a-pics/ It's a slim lead, but from what I saw there, and from your photos, the Armstrong Holland is Aussie made under license from Bucyrus Erie. Your lift arms look just like the BE arms from bulldozer setups here. The BE setup was common on IH machines. General Gear seems to have some old hydraulic parts so you could try there. Also, considering BE is now a Caterpillar company, maybe just maybe your friendly parts counter guy would be helpful. I know, a long shot, but at least it's something.

Thanks Bruce for that link, nice to see you posting again, though I must confess that is the first time I've seen that Red Power site and I might need a stiff cocktail to recover my senses!:eyebrows:

I'll be buying 2 new final drive bellow seals for this D4 from General Gear so I'll talk to John about this seal issue too if I can't solve it here in Oz first.
Regards
Mike

you might look into the sort of seal used on a hyd spinner motor from a fertilizer spreader truck. They have a series of three or more flaps to the inside and a lip seal for ingress. They are fairly tough, but I have replaced a few due to rusted or worn shafts.