IH 404 Hydraulics

Kent V · Mar 26, 2013

Problem: Hydraulics started to not work, i.e. power steering would pause, 3 point hitch would lift slowly and finally everything stopped.

New filter. Still doesn't work.

Disconnected suction tube and replaced with poly tubing connected to the suction side of the filter and placed the open end into a bucket of fluid. Sucks right up but still nothing works.

Disconnected high pressure line while suction is in bucket. Fluid is drawn up and pumped out just fine, maybe some air? But I can't stop the flow with my thumb so there is pressure.

Next step, put pressure gauge on high pressure output.

IF No pressure, or Low pressure I assume the pump is bad.

IF pressure will develop on the disconnected high pressure line, where do I look next.

thanks,
kent

mkirsch · Mar 27, 2013

DO NOT put the pressure gauge directly on the pump without a relief valve to dump oil back in the bucket. If the pump is good, it will deadhead, and you WILL damage something!!!!

Either you'll blow a hose and get a face full of oil (if you're lucky) or you'll split the pump, or you'll blow the seal and pump all the hydraulic oil into the engine.

Hydraulics are a mystery to most people, so don't think people are ignoring you, and don't take it personal if you don't get specific help. Not many people know how these later tractors work. I certainly don't.

Generally speaking if the filter was THAT bad, the pump got starved for oil and is shot now too.

Is there any unusual noise, whining or squealing while the engine is running? Does the engine sound labored when the hydraulics are hooked up?

If it's not the pump, then I would suspect that a relief valve somewhere in the system is somehow stuck open and letting the hydraulic fluid run through without developing pressure.

Kent V · Mar 27, 2013

Yup, I know enough to let the oil flow, the mystery will be if the pump is working, what next?

Kent V · Mar 27, 2013

This tractor has been in my family for nearly 40 years. The hyrdraulics have ALWAYS whined, but worked perfectly fine. No, the only thing unusual is that it has stopped working. I'm suspecting a stuck open relief valve or bad O rings somewhere but I have no idea how to track it down.

mkirsch · Mar 27, 2013

Barring the miraculous appearance of someone who has intimate knowledge of the 404's hydraulic system, you're just going to have to get yourself a parts diagram of the valve stack and start taking things apart.

john tibbetts · Mar 28, 2013

we recently blundered our way through a 404 international with power steering ,that was a "stone wall" tractor with a broken front end. we found a lot of help here, searched "404 hydraulics" bought a parts manual,an it manual,and made use of Messicks web sight,we could see price and availability at a glance. I hope this helps you.

IH 404 Hydraulics

Kent V

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mkirsch

Well-known Member

Kent V

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Kent V

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mkirsch

Well-known Member

john tibbetts

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