NH 75 hydraulic pump vapor lock

gerawillough · Jul 13, 2024

recently worked on a NH 75, farmer complained of loss of all hydraulics after turning it off hot after mowing hay. i've come up with a simple in the field bleeder port that takes less than a minute to do without taking any panels apart or lifting the hood! take out the large plug on top of the forward pump, place washer on this hose and retighten good, bend line forward zip tie it to metal injector line bracket on side of engine directly behind the lift arm frame, so it can be bled from standing at the base of the step. start engine loosen bleeder bolt on end of hose until the air & bubbles come out then tighten, by the time air fills that hose enough to interfere with the pump operation again, it will be many months from now!

SilentJ · Jul 13, 2024

Is that a pressure port ? Is the engine drain hose pictured …. Rated for the pressure that port sees ?

gerawillough · Jul 27, 2024

It is not under that much pressure as i can tell, i can't find pressure rating on that hose assembly, but it seems extremely heavy duty and yes the hose is pictured from Amazon page.

Harry in Ky · Jul 27, 2024

Assuming you mean the port on the hydraulic pump pressure outlet flange? As in item #7 in this diagram.

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There are literally thousands of tractors out there using that (or a similar) fitting with plugs like that. I doubt that any of them have a hose like that attached. Maybe you can explain why you think you need one. If there's a problem with the system, why not just fix the problem?

gerawillough · Jul 29, 2024

Harry in Ky said:
Assuming you mean the port on the hydraulic pump pressure outlet flange? As in item #7 in this diagram.

Lifter, Lines | New Holland Agriculture | MyCNH US Store

Find schematics, manuals, specifications and diagrams for LIFTER, LINES. Find genuine OEM parts for your needs.

www.mycnhstore.com

There are literally thousands of tractors out there using that (or a similar) fitting with plugs like that. I doubt that any of them have a hose like that attached. Maybe you can explain why you think you need one. If there's a problem with the system, why not just fix the problem?

This tractor is known to suck air from somewhere, ( others complain of the same issue) can't find where, not sure why it can be ran for 8 hours straight with no issues, then run it again the same way and nothing hydraulic will work when i get on it after it cools, no other NH tractors i have vapor lock!
Put the hose on it to bleed without lifting hood and taking heat shields off, a very quick field fix! Plus the length of the hose, will allow a lot of air before it backs up to the pump, just a cheap and practical fix to something these 75's seem to have an issue with.