743 Hydraulic Pump Noise

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pondfishr

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Oct 11, 2005
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216
My 743 runs good but it has always had a pretty loud noise coming from the hydraulic pump. When it ildes it seems to be louder. It is especially loud when it is sitting still almost a growling sound. I do need to adjust the creep on the machine so when it is stationary it does have a load on the system due to the steering creep. Also is there anyway to tell what the problem is that is causing the noise. The question is how loud is too loud and telling me it has a problem. The machine is a 1986 model that I have owned for around 5 years. I have no idea how many hours are on the motor but it started a couple of weeks ago at 10 degrees F with 30 seconds glow first crank.
 

Tazza

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Dec 7, 2004
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Its really hard to say how loud is acceptable.
The hydrostatic pumps on the 743s i think are noisy no matter what. All the ones i have owned made a fair amount of noise when turning, but stationary they are pretty quiet. You may need to adjust the position of the steering sticks so there is no load on the pump though.
Does it still make noise after you have let it warm up? as 10 F is a touch cold the oil may be a little thick.
 

Fishfiles

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Feb 8, 2007
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Its really hard to say how loud is acceptable.
The hydrostatic pumps on the 743s i think are noisy no matter what. All the ones i have owned made a fair amount of noise when turning, but stationary they are pretty quiet. You may need to adjust the position of the steering sticks so there is no load on the pump though.
Does it still make noise after you have let it warm up? as 10 F is a touch cold the oil may be a little thick.
As Tazza mention , adjust the creep before trying to find the noise as the creeps will cause noise from the pump , sometimes I see where you think you have it neutral'ed out as it don't move but the noise is still there , a little more adjustment and the pump goes quiet
 
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pondfishr

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Oct 11, 2005
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216
As Tazza mention , adjust the creep before trying to find the noise as the creeps will cause noise from the pump , sometimes I see where you think you have it neutral'ed out as it don't move but the noise is still there , a little more adjustment and the pump goes quiet
Yes it doesn't seem to make a difference how cold or warm it is outside it makes the noise no matter what. I will try to jack the machine up and see if I can adjust the steering. If the 743 pump usually make noise i will run it till it either keeps working ot stops. I didn't know if it was a sign of something I need to check on before it got worse. I will let you know how the adjustment works out when done.
 

Treegator2016

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Mar 6, 2019
Messages
5
Yes it doesn't seem to make a difference how cold or warm it is outside it makes the noise no matter what. I will try to jack the machine up and see if I can adjust the steering. If the 743 pump usually make noise i will run it till it either keeps working ot stops. I didn't know if it was a sign of something I need to check on before it got worse. I will let you know how the adjustment works out when done.
Mine was making a whining sound and had difficulty lifting. It finally gave out and the mechanic says there's a crack in the housing and need to replace the pump? I thought I might try rebuilding it. Any suggestions?
 

walio123

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Dec 9, 2013
Messages
348
Mine was making a whining sound and had difficulty lifting. It finally gave out and the mechanic says there's a crack in the housing and need to replace the pump? I thought I might try rebuilding it. Any suggestions?
If there is a crack in the housing on gear pump, it is irreparable. Even if somehow the crack is welded / glued , it will break the geometry of the housing, it will have to recover, it is almost impossible. It is easyest to make or buy another housing / very few manufacturers offer it /and price will be almost like a new pump. By putting the worn parts in it, repairs are made with a vague result and poor reliability.Better buy a new one, these are just my considerations.
 
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