# NAA 1954 Hydraulic Failure and Repair Advice



## aquaholic

this is long but i'll try not to leave out any of the details. I have experienced complete and sudden 3 point hydraulic failure. 3 point arm have gone absolutely dead. the don't even move 1/4 inch. They worked fine 5 days before when i last used the tractor. Now i have nothing. I expect that something became disconnected so i removed the top plate that the seat is bolted to. I backed out the acorn nut on the outside of the case before i lifted the cover off because thats what my service manual said to do. Inside i found a tube connected to the acorn nut (labled A) that just lays down in the sump of oil. It pivots on the bolt connected to the acorn nut. Should this tube just be laying down in there? It doesn't appear to be connected to anything. There is also a clamp/bracket on the tube (labled B) that i can't figure out where it goes. I cannot seem to pivot the tube up so that i can see the other end because it goes down under the casting and is to long to pivot it up to see the end. I stuck my hand down in the hydo fluid and nuthing is connected to the other end of the tube. Is all this stuff normal? Anyone know what this is and why it's just flopping around in there? And possibly where that clamp goes on and attaches to?


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## sixbales

Howdy aquaholic, welcome to the forum.

When your lift ceases to function, the first thing to check is the hydraulic pump. The pump may have lost prime for some reason. Hopefully, you have a piston type pump. See attached diagram. Install a 3000 psi pressure gauge into the test port (item #3). You can fill the pump with fluid through port #17 (and also thru the test port). Your manual should also cover this. 

The tubing clamp fastens to the upper bolt of the round cover with the hydraulic dipstick. Someone has put the long bolt in the wrong place. Drain the reservoir and find the nut and lock washer (bottom of reservoir) that fastens the tube to the bolt.

Tube "A" appears go into a receptacle at the bottom of the reservoir. Tube "B" is open ended, yours looks to be bent. Drain the reservoir and take another photo of your situation.


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## sixbales

While you have the lift cover off, you should service the unloader valve and safety valve to ensure to ensure neither is stuck open. Test the system with compressed air to ensure it is working properly.


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## aquaholic

thanks six. assuming the arrow i drew is pointing to where the unloader valve is, can i simply knock it out from the other side with a socket or can i stick a rod in there from the other side and tap it out with a hammer?


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## sixbales

Hey aquaholic,

Yes, you can drive it out from behind. I can't tell by looking at your arrow in the photo if that's the unloader valve or not. You'll have to determine that. See attached parts diagram (Items 4-7).


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## aquaholic

i pulled that unloader valve out and it looks fine. it still has the o-ring on it. is there anything else i can check before the new gasket kit arrives?


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## BigT

The problem is you haven't fixed anything?? If you haven't drained the fluid, do so and look for parts on bottom. 

Work the controls and observe for a malfunction or links that may have disconnected. Find the cam follower pin to be certain it hasn't broken off. 

Can you function test the system with compressed air?


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## aquaholic

i did drain the fluid out. no parts of any kind in the sump. i did work the lift lever and it seems to be all connected. i did not see a safety valve, screen or filter in there anywhere though.


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## sixbales

See attached picture of safety/relief valve posted by *JMOR* on the YT forum.


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## aquaholic

i saw the pics but they cant be bought anywhere that i can find. i think at this point i'm gonna replace all the gaskets and o rings that come in the kit i purchased and hope that they fix whatever is failing.


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## aquaholic

i dont see this part identified in my manuals or parts diagrams. is this something i can remove or service? the housing is loose and i can turn it 1/4 inch in either direction. it looks like its aluminum or pot metal or something like that.


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## sixbales

Hey aquaholic,

That is your safety relief valve. This valve could be leaking or stuck open with some sort of foreign material between the ball and the seat. You cannot take it apart because it is factory preset pressure release. Can you pressure test it to determine that it is not leaking off?


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