Checking/Setting Hydraulic Pressure

[Bartcephus]

How do I check the hydraulic pressure on a NH 1510? Where can I find pressure guages and where do I attach them? I've looked through the owner's manual and can't find that information. Any ideas?

 

[jlrsn]

I don't know the first thing about a NH 1510 but am very familiar with hydraulic systems. My advise to you is to get your hands on a NH 1510 Service Manual which should show you the location of the Hydraulic System Relief Valve and where you should take pressure readings. All my gauges that I've used had to be certified but I'd look up what the pressures should be and then buy a glycerin filled gauge that covers the pressures that you are going to check. One good source for hydraulic oil pressure gauges would be McMaster-Carr. I just checked and found good quality hydraulic oil pressure gauges starting at about $34 without certification. I'd stay away from overly cheap hardware store type or automotive type gauges. You would then plumb into the hydraulic system with a hose connected to the gauge and if you need to increase the pressure you would loosen the relief valve lock nut and screw in the adjustment screw while watching the gauge. If prepared it is quite easy to do.
Good luck,
Jim

 

[Soundguy]

I'd also go with a liquid filled gauge.. 0-3000 psi will be fine for ag pressures which usually don't get above 2500 psi. And I'd deffinately get the service manual in hand.

On units with remotes, you can simply adapt the gauge to a QD and plug in then dead head. on units with no remotes you will likely be chaining the upper (rear) lift arms down to the axle then attaching you gauge to some point on the high pressure side, then exercising the lift momentarily.. at least that's how the older fords did it.

soundguy

 

[jenkinsph]

Some good points in above posts but I would use a good 5000 psi guage. It is generally more accurate to use a guage where the center of the scale is in the range you wan't to check. I have an older Lenz glycerin filled guage but don't know how accurate it really is.

 

[Soundguy]

the larger the range, the harder for it is to see where that needle is.

on a 3000 psi gauge, you don't have excess resoloution you are nearing full scale onthe high side, without much waste.. why use a gauge that your needle is going to use a smaller protion of the gauge .. thus each range increment is larger... remember.. this is an ag application... don't often find over 2500 psi, and psi in the range of 1500-2500 are the most common. I don't want to be searching for small increments on a 5000 psi gauge with a 1500 max pressure is what I'm making, vs a smaller gauge and larger increments... ie.. more precise.. especially if you are looking for 'cracking' pressure and then compairing to full open.. which in some cases can be 50 psi difference. 50 psi is gonna be ALOT easier to determine on a 3000 PSI gauge than a 5000+ gauge... the larger the gauge, the less needle movement on pressures much lower than full scale. the lessened movement equates to making it harder to determine actual pressure.

soundguy

 

[Egon]

don't often find over 2500 psi,

And what if you do find pressure that is over the 3K gauge?

Guages come with quite a few different face sizes so the larger ones may be readable.

Then you must also take into account the accuray of the guage all the small differences may not mean much other than indication.

 

[Soundguy]

And what if you do find pressure that is over the 3K gauge?

I normally don't respond to your posts.. but this one begs a response.

Obviously, as my previous message had stated.. you have the service manual in hand and should have RTFM before you do any dinking with the hyds. since the specs for the hyds will be in that manual, you will know ahead of time what pressure range you are dealing with..


soundguy

 

[Egon]

you will know ahead of time what pressure range you are dealing with..

So; you are dealing with a hydraulic problem and using a pressure Gage to trouble shoot. Could the hydraulic problem involve a malfunction that allows the pressure to exceed what your manual gives you??

Are not some hydraulic pumps positive displacement??

If'n I can recall I beleive the manual for my toy tractor calls for a 10000 pound gauge.

 

[jenkinsph]

A good quality 2.5" to 3" guage with a 5000 psi range should be easy enough to read without problems.

 

[jlrsn]

And what if you do find pressure that is over the 3K gauge?

If you are expecting 2,500 PSI and upon checking the pressure the needle pegs above 3,000 PSI you know immediately that you have to lower the pressure with the Pressure Relief Valve. Pressure Relief Valves today are simple and almost foolproof so if the Hydraulic System should have a max pressure of 2,500 PSI and you found over 3,000 PSI the Pressure Relief Valve would have to have been mis-adjusted by someone who didn't know what he or she was doing. If anything I normally find the pressures to be less than the specs.

Also, if I found over 3,000 PSI I wouldn't trust that the Bourdon Pressure Tube of the Gauge was not damaged by exceeding the max pressure of the gauge and I would replace the gauge.

I use 4-1/2" to 6" Diameter Calibrated Gauges that are tested on a regular basis to NIST Standards with a Certificate of Calibration for Aviation use. I use a 4 to 6' Flexible Metal Shielded Hose with a Teflon Inner Tube to connect the Gauge to the Hydraulic System. That allows me to hang the Gauge close to the Pressure Relief Valve that I'm adjusting.
Good Luck,
Jim