1951 Ford 8n hydraulics

ghilljr · Aug 10, 2017

A little backstory on the 8n . I rebuilt the pump and installed a cam follower pin and new rings in the hydraulic piston last year. Lift worked fine with no weight in garage. But before i got to use it with any weight. I got hurt at work. Im finally able to get back on a tractor now. I put the backblade on and it wont lift it. Pulled side cover for a look and its leaking from the hydraulic piston. Im going to pull the top cover saturday after work. I must of did somthing wrong on the piston.Will the leaking piston cause it not to lift any weight?Any thing else i should check?

Soundguy · Aug 11, 2017

Yes, if its leaking out of the piston, it wont lift.what was the bore like on the cyl?

Did you put all 3 gaskets under the cyl when re attaching it?

Hone the cyl?

I'd have honed and used the naa oring style piston, also would have checked the relief while in there.

ghilljr · Aug 12, 2017

The bore had some scratches and i did hone it with a brake hone. Maybe i over did it with the hone. I used the 3 ring piston that was in it. The piston had some damage on the skirt area. I thought it would be ok. I put a new relief valve last year when i dropped the pump.I had new gaskets for the cylinder ,im pretty sure i used them.i will check . i did not get a chance to pull it apart yet, Had to be at work today longer than i expected.

Kirk-NJ · Aug 16, 2017

In my '40 9n it would hold the the implement up as long as the tractor was running but as soon as the tractor was shut off the implement would hit the ground in less than 3 minutes. Cylinder had a gash in it. I could have try to hone it out but switched it with an 8n cylinder off a parts tractor. Took the 3 ring piston out and upgraded it out for an NAA piston with O ring and backer, as Soundguy said. Used a ring compressor so the backer didn't get screwed up when loading into the cylinder.
Put the 8' back blade on and 24 hrs later only dropped an inch or two. I can live with that.

Kirk

Soundguy · Aug 16, 2017

I think a honed/ scratched cyl will likely not seal with the rings.

I'd go naa piston, with a fat cnh oring, re hone ( oring very forgiving on over honed cyls.), just make sure scratches are honed so as to not cut oring.

ghilljr · Aug 16, 2017

Thanks guys , I will order the naa piston and cnh o-ring tomorrow.im swamped at work, hopefully i can get to it real soon.

ghilljr · Aug 16, 2017

Kirk-NJ said:
In my '40 9n it would hold the the implement up as long as the tractor was running but as soon as the tractor was shut off the implement would hit the ground in less than 3 minutes. Cylinder had a gash in it. I could have try to hone it out but switched it with an 8n cylinder off a parts tractor. Took the 3 ring piston out and upgraded it out for an NAA piston with O ring and backer, as Soundguy said. Used a ring compressor so the backer didn't get screwed up when loading into the cylinder.
Put the 8' back blade on and 24 hrs later only dropped an inch or two. I can live with that.

Kirk

i could definitely live with that too. I never checked to see how fast it dropped.

Soundguy · Aug 17, 2017

You can get a rubber or leather backup washer.. Both work.. Leather may be harder to install depending on how you hold your mouth, and how extensive your curse word vocabulary is