The Fordson Tractor Pages Forum

Hello everybody ,

currently I'm in the process of rebuilding the power steering cylinder of a super major. Please have a look on pos. 28 in the link below. There is an uncertainty about the location of this O-ring. I can't reason where exactly this O-ring should be installed. I can't remember if there was an O-ring when I disassembled the parts.
I also have copies of the original shop manual and there are cross-sectional drawings of the assembly (don't know how to post attachments here) and it seems this O-ring pos. 28 is in the back of the spool housing, but in reality there is no chamber to accept this O-ring.

Maybe some forum members also have rebuilt the original powersteering cylinder and do remember this O-ring, where it belongs.
Thanks in advance!
Sjors

https://www.mycnhistore.com/us/en/newho ... 5056875BD6

Can you post a pic of the valve body? (see this: viewtopic.php?f=1&t=5024&p=53955#p53955) This o-ring is in a slot in the valve body and seals the spool from the end cap to ensure there isn't a hydrraulic block of the spool into the turn left position.
Sandy

Billy26F5 wrote: ↑

Mon Jul 03, 2023 3:22 pm

Can you post a pic of the valve body? (see this: viewtopic.php?f=1&t=5024&p=53955#p53955) This o-ring is in a slot in the valve body and seals the spool from the end cap to ensure there isn't a hydrraulic block of the spool into the turn left position.
Sandy

Hello Sandy, thanks for your message. Please see the pictures.

Top picture: topic is the O-ring next to the valve body, with metric size written by me in mm with blue pencil.

Second picture: where is the O-ring visible in the cross section?

Third picture: valve spool with new O-ring (this is of course not the O-ring where this topic is about)

Last picture: bore of valve body.

Where should the O-ring be installed?

Hi,
there's an o-ring sitting under the reaction ring. Did you undo the locking nut? you need to put the nut back on specific tension.

I did mine twice, but still leaking a bit. I suspect this ring or the one that goes around the reaction ring.

Hello,
I already replaced the O ring between reaction ring and the spool valve shaft where the reaction ring is zitting. I mean the O ring where my blue writing is on the first picture: where to put this o-ring?

I can't really see all that well, but there does seem to be a groove for the o-ring, a pic from the ram end of the valve body would be handy for that.
Sandy

Hello Sandy,
the ram-end of the valve housing consists of a circlip followed by the end cover incl O-ring to seal this cover.
According to the exploded-view drawing, the O-ring (the O-ring where this topic is about) should be installed through the bore end of the valve housing, not the ram-end of the valve housing. I can be possible the O-ring should be installed via the ram-end, but I never removed the end cover so if there should be an O-ring I never removed it.
The steering system worked fine before disassembly.

I'm not sure if you've read the whole section but it's well worth it, and this o-ring is meant to be removed from the ram end. The reason for showing it at the valve end of the diagram is to show what the o-ring seals, not the end to remove it from.
Sandy

Hello Sandy,
so you think it is this O-ring?

I do indeed, if you don't have a spare o-ring for the end cover be really careful with it till you know you can get one just in case it's not available.
Sandy

I'm busy with the power steering and I think I solved the mystery on O ring 28.
According to the I&T manual there was an early production power steering control valve. this specific o-ring is not on the diagram. It only shows up on the later production power steering cylinder.

Obvious there is also no groove in the early type, seems to be that mine is also an early type.

this is the inside of the valve body:

I see what you mean, it is strange though that you both have that on units supposedly made after the manual supplement from 59. An original manual on the power steering when first introduced would confirm this, as the wording in the I&T and in the 59 supplement suggest the o-ring was fitted to all valve bodies. Whatever the actual moment this change occurred at, if there is a slot there should be an o-ring in it, if not then look around for an earlier manual to confirm.
Sandy