Ford 8N Hydraulics

[JF TX]

Hi there. I've never posted but have been reading for years.

I have an 8N that has a problem with the lift. Last year at the beginning of the season it didn't work initially but once it started it kept going for the whole season. This year is seemed to be the same but only started to work after I removed the load. Anyway, I took it in to the local dealer for a transmission oil change (creamy oil) and they are reporting that it isn't working at all and mentioned that they will try it for a couple of days to see if the seals will expand and start working again. I checked with them yesterday and apparently it still isn't working but they will keep trying.

I have a feeling that I'm going to get it back with new oil and freshly flushed but without a working lift. Is it possible that it has really failed or could it be that it needs to be primed? Any troubleshooting hints would be appreciated.

Thanks,

JF

 

[Briana03]

Welcome to TBN

I moved your thread to the Ford Vintage Tractors Forum.

 

[Dollar Bill]

It will prime itself as the pump is submerged in oil - Just move the lift lever up/down a few times.

If it sat thru the Winter with water in the hydraulics, you could have some freeze damage and at a very minimum rusty valves.

Post back with specific symptoms when you get it back if it isn't working properly.

 

[Soundguy]

i have a feeling your dealer is fleecing you or are complete morons.

'seals start sealing? really? it sounds as if they have never been inside a N style pump or top cover.

as DB said.. the intake is submerged.

most common cause of failure to pump is sticky intake valve.

open inspection cover and you can manually move the valve to allow the pump to draw oil.. and then you can do a bunch of tests from there... check hyd pressure by chaingin lift and plumbing a gauge to test port to check relief.

you can check leak at cyl and gaskets.. etc.

post back if you want help... otherwise guard your wallet. sounds like your dealer doesn't have a clue as to what he's doing..

N hyds are easy to R&R

 

[JF TX]

Thanks for the replies.

I just checked at the dealer and it still isn't working. They replaced the transmission fluid with the genuine Hydraulic fluid. Will this still work the hydraulics in a well used transmission? If yes I'll recover the tractor and start troubleshooting per your suggestions.

Thanks,

JF

 

[Soundguy]

'genuine hydraulic fluid' if that is a straight hyd oil, like an R&O or an ISO 32/46/64 hyd oil.. it's a horrible choice. that oil must lube the tranny and rear end diffy gears. use of that type of oil will lead to premature wear, bear and bearing failure.. and if the thinner 32 stuff.. it would be a poor choice in a worn pump.

A UTF type oil meeting M2c134 spec would be ok as a gear lube, trans lube and hyd oil, .. for lubrication.. however in a worn scotch yoke pump.. if it's weak and leaky.. it will be even more so.,

A gear oil simialr tot he 90wt gl1/3 mineral gear oil used in the system is more like a 50sae motor oil in weight.. and would be better for a worn lift. a modern 80w90 gl 4 or 5 'mt1' oil that is marked yellow metal safe would be ok.. or a 90wt gl1/3 oil.. or similar.. TSC sells a ford lube that meets these specs.. and many others sell 90wt gl1 napa has it part number 65-205 for a 5g pail. most auto stores have it or can get it as well.

still.. oil is not your only issue.. if the sump was dirty and gritty and emulsified, your control valve may be sticking and simply not actuating with the 3pt control handle.

dropping the pump to clean the sump and flush with diesel, replace top and bottom gaskets, 3 gaskets under the hyd cyl.. repalce the piston with a naa piston with oring and backup washer, hone old cyl , replace relief valve, repalce pto shaft gasket and side cover gasket, etc.. will be about 125$ and you can do the work yourself in about 8 hours or so. I'd also repalce the cam follower pin and weld up the cam if it is worn, then adjust the lift to specs using the alternate adjusting instructions in the service manual so you don't have to have the special and unavailable nuday tools.

hardest part of the job will be getting the 3pt linkage apart so you can lift the top cover off and then dropping the pump,..

i'd diagnose it first.. if the lift is not weak or leaking and it is just a sticky control valve.. sometiems a flush with diesel in the oil and manually unsticking it, then a repalcement with good oil once it is freed up is all you need.

unfortunately, as soon as you said the dealer was waiting to see if the seals would swell up and start working tells me they know -0- about your hyd system...

post back

 

[LD1]

Seals.....what seals:confused2:

Maybe they are referring to the metal rings on the hydraulic piston:laughing: I home they dont swell too much.

GET THE TRACTOR AWAY FROM THAT DEALER

 

[Soundguy]

it could already have a NAA piston with oring.. but that 'seal' is a leaker.. not a cause of total loss of lift unless it's blowed out.. and if so.. no amount of letting it set and swell in hyd oil will be helping it.

dealer is unfortunately.. ignorant of the facts pertaining to that lift mechanism... most of that stuff is metal on metal.

 

[JF TX]

Clearly this dealer isn't over familiar with the 8N. Got the tractor home and was surprised to see the lift work normally without a load. I attached the mower but the lift was roughly 50% with weight allowing to mow a coupe of test strips. I don't know if this is likely to improve without intervention or is on the verge of an outright failure.

Any thoughts on if I should do anything or leave alone and see what happens? if I wait am I likely to have a much more expensive critical failure in the near future?


Invoice shows Hydraulic Oil, which they were told was standard by the oil provider. I didn't record what the details of the oil are.

Thanks,

JF

 

[Soundguy]

plain hyd oil is not reccomended or the trans, hds and rear end.

opent he inspection port where the dipstick is and look at the mouth of the cyl, and all around.. any leaks from the top sides when holding up a load?