Hydraulic pump noise on 8N

[EdGooding]

Napa sells a 3,000psi gauge but you'll have to adapt the stem to fit the test port. I made my own with a 3' hose because I'm 6'-6" and prefer to stand next to the lift lever when I use it, rather than be down on my knees.

 

[wolc123]

1951 8N. If I have any weight on the three point, when I lift it up I get a kind of knocking/ratcheting noise. It lifts ok, but the noise is there (not there with nothing on the three point)
Is that a normal noise? It's fresh oil in there and when I had the trans apart I cleaned what little sludge was in there. It seems to operate ok but will go down over a couple of days with a 50lbs (approx) trailer hitch frame on there.

I also have a 1951 8n and I’ve noiticed the same noise, but only when I have a lot of weight on the three point (likely well above its design capacity).

I bought this tractor in 1989, from the widow of the original owner, when it only had 1200 hours on it. I changed the hydraulic oil then, but I have not done it since, so I’m likely over due on that because it now has 2400 hours on it.

The 3-point disk, on it here, works ok with that 150 pound iron plate bolted onto the back but it would not lift it with a second one added (and it made that same noise you describe when I tried).

I very rarely use that disk (the 3-point hitch was the worst thing to happen to a disk), but I did last week because the serrated blades work good for chopping sweetcorn stubble.

The problem was, the ground was a little too wet and several of the inter disk spaces got plugged with heavy mud, pushing the weight above the tractors lift capacity.

When that happened, that “noise” was loud and the disk locked in the full up position. It stayed there, whether I had the draft control lever in the up (position) position - normal for a disk, or down in the “draft” position - normally just used on the plow.

As I crossed a ditch, driving back to get a shovel, with the draft position lever down and the hydraulic control lever down all the way, something “let go” inside and the disk finally dropped to the ground.

I was able to raise it again (with the noise) and again it stuck in the full up position. I thought sure I had broken something, but when I finally got a shovel and removed the trapped mud, everything went back to normal again, and it lifted and lowered without the noise.

With my tractor, that noise is like a warning siren, that I have too much weight on back (I also get it when I’m moving heavy unseasoned firewood with a 3 point carryall). When it makes the noise and “locks up” and won’t lower- it is a sure indication that I do. I would not doubt it, if that noise and strange hydraulic “lockup” feature was built into the tractor, by the Ford engineers back in the 40’s.

There might be a way to adjust the hydraulic load pressure at which that noise starts (it sounds like yours is starting at way too low of a load).

Have you ever had the “lockup” like I described occur ?

 

[Southernspeed]

With something lightweight like my ball hitch frame (40-50lbs?) you can actually see it ‘nudging’ up with every knock sound. It’ll still lift a trailer or rotary rake ok, but I haven’t tried anything that heavy.

 

[wolc123]

With something lightweight like my ball hitch frame (40-50lbs?) you can actually see it ‘nudging’ up with every knock sound. It’ll still lift a trailer or rotary rake ok, but I haven’t tried anything that heavy.

I got worried, when mine locked up last week. I probably shouldn’t have, because it did that a few other times on real heavy loads of firewood.

That was the first tractor that I ever bought. I had a long history with it. My dad would always borrow it, from our neighbor, to disk our garden each spring throughout the late 1960’s and 1970’s.

The only work that neighbor ever did with it, was working his 1/2 acre garden. When I got it, it had very little wear, and was just barely broken in. It had then as it still does now, the original paint and tires on it and it has always been stored inside.

Those things were so damn overbuilt, compared to the poor excuse for tractors that they sell these days, that it probably still has another lifetime or so of use in it after I’m done with it.

 

[EdGooding]

I got worried, when mine locked up last week. I probably shouldn’t have, because it did that a few other times on real heavy loads of firewood.

That was the first tractor that I ever bought. I had a long history with it. My dad would always borrow it, from our neighbor, to disk our garden each spring throughout the late 1960’s and 1970’s.

The only work that neighbor ever did with it, was working his 1/2 acre garden. When I got it, it had very little wear, and was just barely broken in. It had then as it still does now, the originalW

Working a 1/2-acre garden is babying an 8N. I bought my '52 from the original buyer. He farmed 77 acres of corn, soybean, and hay with it from '52 until I bought it in '95. He took great care of it and it was not beaten down any when I got it from him. He could no longer get up on it so he sold it. He teared up when I loaded it on my trailer.

 

[John0829]

Guys the knocking is purely the scotch yoke that has worn some making the noise, not something "designed" into the system. A fresh built pump with proper clearances will NOT knock no matter the load and when overloaded the relief valve will simply open as with any hydraulic system.

The scotch yoke is what moves the pumps piston thus you could see, in the right circumstances, a pulse in the lift arms in time with the knock.

Now as for the "lock up" that is a sticking control valve, a common problem, usually caused by contaminated oil. Occasionally a valve might be worn but that again is usually from contaminated oil. The one failing, if you will, with these old Fords is the hydraulics. Being a common sump for the transmission, hydro and differential allows for a lot of potential debris to circulate into the pump and valve.

Like most tractors the regular/scheduled servicing of that sump, especially on these old tractors is usually overlooked. Generally it is not done until there is water making the oil milky looking that it is addressed and sometimes not even then until something stops working. ANYONE who has cleaned one out knows full well the sludge build up that develops in the sump, there have been instances where the pump and top cover removal was necessary in order to clean it.

 

[wolc123]

Guys the knocking is purely the scotch yoke that has worn some making the noise, not something "designed" into the system. A fresh built pump with proper clearances will NOT knock no matter the load and when overloaded the relief valve will simply open as with any hydraulic system.

The scotch yoke is what moves the pumps piston thus you could see, in the right circumstances, a pulse in the lift arms in time with the knock.

Now as for the "lock up" that is a sticking control valve, a common problem, usually caused by contaminated oil. Occasionally a valve might be worn but that again is usually from contaminated oil. The one failing, if you will, with these old Fords is the hydraulics. Being a common sump for the transmission, hydro and differential allows for a lot of potential debris to circulate into the pump and valve.

Like most tractors the regular/scheduled servicing of that sump, especially on these old tractors is usually overlooked. Generally it is not done until there is water making the oil milky looking that it is addressed and sometimes not even then until something stops working. ANYONE who has cleaned one out knows full well the sludge build up that develops in the sump, there have been instances where the pump and top cover removal was necessary in order to clean it.

Considering that my hydraulic oil has only been changed once in 72 years , I’d be inclined to agree with this. I’ll get on that this winter. I think tractor supply still has that “universal tractor fluid” by the 5 gallon bucket, which I think is what I used when I changed it last, back in 1989. It hadn’t leaked any and is still in the “good” range on the dipstick.

Meanwhile, I’ve got to get my two section drag on it Monday to work up a couple of weedy acres for planting a wheat/white clover mix. It don’t struggle, lock, or make a peep of noise while lifting that 6 ft wide tool.

 

[EdGooding]

Considering that my hydraulic oil has only been changed once in 72 years , I’d be inclined to agree with this. I’ll get on that this winter. I think tractor supply still has that “universal tractor fluid” by the 5 gallon bucket, which I think is what I used when I changed it last, back in 1989. It hadn’t leaked any and is still in the “good” range on the dipstick.

Meanwhile, I’ve got to get my two section drag on it Monday to work up a couple of weedy acres for planting a wheat/white clover mix. It don’t struggle, lock, or make a peep of noise while lifting that 7 ft wide tool.
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Well, if it hasn't been cleaned in 72 years you are in for one nasty job, one that you won't want to do again but will never have to in your lifetime. Get some rags that you can toss out when done, something to scrape with (I've used plastic Bondo spreaders and gasket scrapers), and your favorite solvent that you can put into a spray bottle (I like Acetone because I use it for cleaning gun parts but it is highly volatile so use it in a well-ventilated area and have NO source of open flame anywhere near it). Buy a new relief valve and replace the one there. Drop the pump - be careful because it is a lot heavier than most suspect and you don't want to drop it on your chest. Remove the inspection covers and get a light. Get to work and you'll be good to go when done.

 

[wolc123]

Well, if it hasn't been cleaned in 72 years you are in for one nasty job, one that you won't want to do again but will never have to in your lifetime. Get some rags that you can toss out when done, something to scrape with (I've used plastic Bondo spreaders and gasket scrapers), and your favorite solvent that you can put into a spray bottle (I like Acetone because I use it for cleaning gun parts but it is highly volatile so use it in a well-ventilated area and have NO source of open flame anywhere near it). Buy a new relief valve and replace the one there. Drop the pump - be careful because it is a lot heavier than most suspect and you don't want to drop it on your chest. Remove the inspection covers and get a light. Get to work and you'll be good to go when done.

Sounds fun, but I’m just going to drain out the old oil, fill it with new, and hope for the best. The little bit of knocking noise at heavy load never bothered me much, nor do the occasional lockup’s when overloaded.

 

[wolc123]

You had me a little worried about the 30 some year old hydraulic/rear end oil in my 51 8n EdG, with those nightmare tales of milky sludge and acetone.

I pulled the dipstick and the oil color still looks good. The old girl lifted that drag without any funny noises. I think I’ll just let my grandkids worry about changing it, in another 20-30 years, if they feel like it. Looks like there’s lots of life left in the oil that’s in it.

Off to the wheat field now, to go over it once before sunset tonight. I’ll hit it again in the morning then sow my wheat and white clover.