856 hydraulic pump pressure port o ring

[patmax61]

Concerning the big pump in the transmission of the 856: I've had problems in the past with the o ring on the pressure port that connects the pump cover to the transmission housing. 

I tried to get a new one at the IH dealer this winter. Parts lookup showed 2 different o rings. I assumed 1 fit the older 06's and the other fit the 56's. I took the pump cover plate right to the counter to make sure to get the right one. They brought both of them out. One was too big in circumference so that was out. But the other one was a very loose fit in the recess provided in the cover plate. I believe it should have been a snug fit but the parts guys said that there was no other option. I had to stick it in place with gasket cement and work carefully not to dislodge it when I mounted it to the tractor.

I have little confidence in this o ring going into the busy summer season. I believe I read on this website some years ago about someone who made a teflon reinforced o ring to cure this problem. Anyone out there remember or know who sells that special o ring?

[Nebraska1206]

IH offers the Teflon ring that can be placed inside of the oring on the hitch pump mounting plate.

1970904C1 is the teflon ring that'll fit the 06 series tractors and earlier s/n 56 series.

388591R1 is the teflon ring that'll fit later s/n 56 series tractors on up to the 86 series.

These teflon rings were used by IH for sealing the draft control valves to the rockshaft cylinder on most larger IH tractors since the 06 series.

[FarmerFixEmUp]

Ag Parts has them listed too. 

http://www.agpartsltd.com/shopping/productDetails.aspx?i=1053096

 

[Long Farms]