Measuring hydraulic pressure

[Tom in TN]

I know little to nothing about hydraulics on a tractor. My 3 point works well and a front end loader that I have on my four cylinder Ford 4000 diesel
works well. I've never measured the amount of hydraulic pressure because I haven't the first idea how to do so.

Would you tell me what pressure gauge(s) I need to do so, and how to use the gauge?

Thanks for any advice you can give me on this matter.

Tom in TN

 

[Russ from MN]

If it works well I don't know why you are concerned about it, but TractorData says it should develop 2500 psi. To confirm that you could put a T in a line with a gauge and then deadhead that circuit. Just remember it's over 45 years old, but if it's in reasonable shape it should develop that much pressure. A hydraulic system can work well with a much lower pressure.

 

[Steve@Advance]

There's most likely a test port to put a gauge into.

But there is more to it than just putting in a gauge. Unless someone posts the page from the shop manual, or gives exact instructions, you will need a shop manual to walk you through it.

 

[guido]

Tom in TN,


Hydraulic pressure is like engine oil pressure, it varies with operational load.

Pump pressure usually is easy to check on a tap on the pressure side. Pressure reaching a cylinder will require T inline with the port you are checking.

Of course you will need to know what the expected good pressure should be,

Guido.

 

[PJH]

Tom - I seem to remember that your hydraulic pressure concerns came up when you were in the market for a round baler. I can't speak for every baler and every tractor, but my old JD 630 makes about 1200 PSI and it works the hydraulics on my NH 848 round baler just fine. I think the book for my baler recommends hydraulic pressure in the neighborhood of 2000 PSI? It's been 20 years or more since I read that part of the book. I thought I'd mention that what they recommend and what will work are not the same in every case. Also - my relief valve squeals on my tractor when I close the end gate. That always worried me since I knew about the baler pressure recommendation and the lower output pressure of my tractor. It turns out that they have a fluid restrictor in the baler hydraulic system to keep the end gate from slamming shut, and that is what is causing my relief valve to squeal.

 

[MarkB_MI]

I know a fellow who used the high pressure oxygen gauge off his oxyacetylene rig to check a tractor's hydraulics. Worked like a champ.

Of course when he put the gauge back on his regulator, it sploded the first time he turned on the gas.

 

[Tom in TN]

Mark,

Yikes! That sounds like a dangerous situation.

Tom in TN

 

[Tom in TN]

PJH,

That's exactly what prompted me to look into the pressure. I'll take look at TSC to see if I can find a gauge that will go up to the 2000 psi range.

Thanks for the info.

Tom in TN

 

[Tom in TN]

Guido,

Thanks for the info. I'm not experienced in it, but I'm going to have to learn a bunch of stuff. Right now, I only have one control valve and it's hooked to the front end loader. The loader is a trip bucket so I don't even have hydraulic control for the bucket to go up and down.

Lots to learn.

Tom in TN

 

[Tom in TN]

Thanks Steve,

I have an honest to goodness Ford service manual (not just an I/T manual). I've never before been concerned about hydraulic pressure, so I've never looked for that info in the manual. Another thing I need to do!

Tom in TN

 

[Tom in TN]

Thanks Russ,

I'm in the process of looking into moving to a small round baler. All I have ever worked on is a small square baler. I think there is something about needing a specific amount of pressure to open the rear door of a round baler, so that's what has prompted this question

Thanks for your reply.

Tom in TN

 

[Russ from MN]

Yes, I think it says right on the gauge, NO OIL

 

[kencombs]

4000 psi gauge with liquid dampening. It's always best to use a gauge that reads your intended pressure near the middle of its scale. those without liquid will be damaged by the hydraulic shocks.

Here is an example:
https://www.surpluscenter.com/Air-Pneumatics/Pressure-Gauges/Pressure-Vacuum-Gauges/5000-PSI-2-5-LF-LM-Gauge-Dynamic-CF1P-350-A-21-1246-L.axd

 

[Destroked 450]

If your front end loader will pick up a good sized load your tractor will have no issues working the trail gate on a small round baler.
My baler never has more than 1500 psi on the bale chamber and it takes lees than that to open the tail gate.

 

[dcarp]

Some of the Older Case & Hesston balers have their own hydraulic pump, just need a tractor with a PTO to operate. Might be an option if you have an issue with tractor hydraulics.

 

[buick8]

NEVER put anything flammable in a compressed air system, much an oxygen system. If you ever see a compressed-air system explode, you will not soon forget.

 

[87nassaublue]

He's lucky he survived that moment of insanity. Anyone who knows about oxyacetelene rigs knows how dangerous that is. Fire and explosions isn't something to take lightly.

 

[caterpillar guy]

With a 4000 psi gauge screw it to one of your male couplers plug into the tractor coupler and hold lever with it running half throttle or so. You should see the pressure in the middle of the range probably in the 1800-2500 psi range. Could be as much as 2500 psi though would doubt it being over that by much of any. Most of the latest tractors are still only about 3000psi at most. Construction equipment has some pieces at much higher levels like in the over 5,000 psi level.