Testing a hydraulic pump

[Xfaxman]

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I recently ran low on hydraulic fluid in my International 434. After I refilled, the hydraulics gradually gave up after a couple of sessions.
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Cheers

Bob

Two questions.

1. What type hydraulic fluid or motor oil does International specify for it?

2. What type hydraulic fluid or motor oil did you put in it?

You didn't answer my questions. I have no experience with your model tractor, but I did have a Case tractor that I bought at an auction that lost hydraulic power after the fluid warmed up.

I drained the thin hydraulic fluid, refilled with the recommended motor oil and it worked fine from then on.

 

[wdchyd]

wdchyd;

How much does a test like that usually run? I'm really new to tractors and hydraulics. I got a Mitsubishi MT 372 D/Satoh 370 Beaver tractor to move dirt. It seems to run fine after startup but not fully warm. After I move dirt around for a while or just drive around, I lose hydraulic power to lift the bucket. Yesterday, I swapped lines from the bucket tilt and bucket lift to verify it wasn't my valve and I still lost power after a little bit of working. I bought a used hydraulic pump and the seller guarantee's the pump works. I want to take the pump when I receive it to some place to get it tested before I put it in my tractor and verify it meets some standards before I install it.

Typically the charge would be $85 in our shop. We'd rather test pumps right on equipment to determine other problems if warranted (air entrainment, cavitation, worn splines, bad relief valves ect)

We are very selective when it comes to testing pumps cuz we don't want to contaminate the oil in the test bench in a case of a trashed pump

 

[dfkrug]

We'd rather test pumps right on equipment to determine other problems if
warranted (air entrainment, cavitation, worn splines, bad relief valves ect)

Yeah, that makes a lot of sense. Too often, the pump is blamed when the problem is with the
valve(s), fluid, or plumbing. Same seems to happen when an engine won't start: must be the starter
motor, right?

Anyway, a simple pressure test on the tractor is the first step. Flow tests are rarely needed
in my experience with CUTs.

I buy hyd pumps, motors, and valves (Surplus Center and eBay dealers mostly), but this is one area
where I want new parts as used parts are often dirty inside. Dirt and hydraulics do not mix.

 

[Alesandro]

Too often, the pump is blamed when the problem is with the
valve(s), fluid, or plumbing.

What are some trouble shooting techniques that a newbie can do? All this makes sense, I just have no clue where to start.

The scenario is when I 1st start up my tractor, the hydraulics work fine. After awhile of use I can't even raise an empty bucket.

I have emptied the hydraulic fluid and replaced with what our local hydraulic shop recommended (CostCo stuff, let me know what you think of that) and cleaned the hydraulic filter (yes, it was very dirty). It worked better for a while, like an hour, then lost bucket lift power. The next day I switched the hydraulic lines between the bucket tilt and bucket lift and still the same response. As far as bucket tilt, it seems to lose power too. To me it seems since I changed the lines that would determine it's not the particular valves for the bucket lift since I experienced the same issue that would have been the bucket tilt valves.

Thanks for the help.

 

[mrmikey]

Fist, and cheapest thing to do if you're working on it yourself, is put a pressure gauge on the main pressure line.
EDIT
So you cleaned the suction strainer? and found crap, it worked good for awhile and then went bad again?. If so, check the strainer again, if it's been run plugged for awhile, it won't do the pump any good.............Mike

 

[Alesandro]

mrmikey;

You know that has always been a thought of mine as well but then I got distracted. I will check that tonight or tomorrow if I can find the time and if it's not raining.

Great suggestion! Thank you.

 

[dfkrug]

What are some trouble shooting techniques that a newbie can do?

Mike beat me to it. Contaminants in the oil are a strong suspect.

 

[Xfaxman]

What are some trouble shooting techniques that a newbie can do? All this makes sense, I just have no clue where to start.

The scenario is when I 1st start up my tractor, the hydraulics work fine. After awhile of use I can't even raise an empty bucket.

I have emptied the hydraulic fluid and replaced with what our local hydraulic shop recommended (CostCo stuff, let me know what you think of that) -----------------------------------.

Thanks for the help.

Sounds to me like it needs motor oil, not hydraulic oil. Get an operator manual for it, find out for sure.

My Bobcat V417 uses 15w-40 motor oil. :thumbsup:

 

[mrmikey]

Contaminants in the oil are a strong suspect.

What I was thinking also, either plugged up now or it's been plugged and been cavitating for so long the pump is shot..............M

 

[Alesandro]

So for those that say to put a pressure gauge on it. I'm going to get a pressure guage and hook it up to one of my lines, but how much pressure should I expect to see?