Hydraulic oil aerating in diff/trans

[CoyPatton]

Hello all,
Quick question for you gurus. I have a 1300D, runs great but has a loud knock that is a little troubling. I have changed the oil and filter on the motor. Running 15-40 in the motor. I don't believe the knock is from the crank or rods. I believe it is coming from the hydraulic pump. the fluid in the rear diff/trans is white/aerated. At first I thought it might have been water but if you put some on your fingers it will clear out and is just oil. I have a 155d manual but it isn't clear. where is the screen / filter for the hydraulics? I am going to check the screen, clean it and change the fluid and see it it gets any better/quieter. Any other ideas would be welcome also.

I apologize for taking over your post to correct misinformation on hydraulic functioning.
Now another thought that crossed my mind related to your possible air problem, is a very small hole or even a very slightly loose fitting. This would most likely be on your suction line going to your pump. Anything on the pressure side would most likely be spraying out fluid. You will have pressure on the hydraulic system anytime the pump is operating. Unless you have sheared the shear pin your pump will be operating anytime your tractor is running. A suction side ‘leak’ can be a pain to find. Clean the suction line including fittings and check for wet spots. The suction line will eventually connect to the screen that has been mentioned. The flow is from the reservoir through the screen through the suction line to the pump to the smaller pressure ‘line’ back to the system. Not knowing your tractor setup, there could be a number of places the pressure line goes at this point.
If you have a FEL, pressure is diverted somewhere to supply it, id you have spool valves in addition to your 3ph lift valve pressure is diverted there also. Each of these hydraulic valves will allow the flow to continue past them to return to the reservoir until the valve is trip to divert the flow. But flow continues regardless and pressure is present to push the flow.
Good luck on finding the source of your ‘bubbles’.

 

[careyo63]

I could care less about your POS. 2002. Go high jack another thread. I don't apply here. You have 12 Gears we have 8 so not even close. Not a whole lot of people care WTF. you think if you haven't noticed. I been around this form a long time and never had the first problem on here but from one Person. And lo and behold you sound just like him. Change your name. I would have to......

 

[CoyPatton]

I could care less about your POS. 2002. Go high jack another thread. I don't apply here. You have 12 Gears we have 8 so not even close. Not a whole lot of people care WTF. you think if you haven't noticed. I been around this form a long time and never had the first problem on here but from one Person. And lo and behold you sound just like him. Change your name. I would have to......

Ranting name calling old man be what you are.
You proved my points! And as for hi-jacking, you insist on having your way even when you realize you are wrong. It sure appears to me that just like a liberal you accuse others of what you do!
Just go away!
I dripped out of one, but I refuse to allow a crazed liberal run me away or to get someone hurt with outright false information. Hydraulic fluid under pressure can be injected into the skin. Your 3ph valve diverts pressurized flow it does not create pressure nor flow. When not diverted to raise the implement the pressurized flow goes to the reservoir.

 

[CoyPatton]

Seems someone got out the wrong side of the bed this morning!

Not my first cross with him. There is only the wrong side of the bed when he figures out he is wrong and someone points it out.

 

[careyo63]

Here you are again with 2 posts. And I need to leave. Your a Wack Job!!! Nobody said anything about Hyd. pressure penetrating your skin. Or taking lines loose or how that even came up for that matter. You got big problems buddy...........:confused2:

 

[clemsonfor]

Learn your yanmars, I wish I had a power shift but no go. Go check it out!
Mine has 1 reverse and 3 forward in 4 ranges (C, 1, 2, 3) non-synchronized.
You prove by all your going on that you lack basic mechanical understanding of how a pump works. But worse is you provide information that could result in someone getting seriously hurt. Someone will thing by your information that they can open a hydraulic pressure line and since they have not called (in your example) raising the 3ph there is no pressure present.
I beg to correct this misinformation because if the pump is operating then it is producing pressure and flow. Note operating. That typically is happening when the engine is operating. If it is not you have problems. Same goes for the injection pump and the water pump (if present, as not all Yanmars have water pumps).
As for your name calling�o ahead you tell way more about yourself by that than you ever will about the person you call names.

Doesn't Powershift run off a separate pump in the transmission?

 

[CoyPatton]

Doesn't Powershift run off a separate pump in the transmission?

That is my understanding also, although not totally sure. The ymXX10 and ymXX20 are the power shift models. There are several different PTO hp models that run the power shifts. But the ym2002D that I have is just a plain old gear driven tractor. It dies have the crawl range which is a bit unique (and very rarely used). It even has a 10mm hex pin that blocks going into to crawl range. And even 3 gear in crawl is turtle slow.

 

[clemsonfor]

That is my understanding also, although not totally sure. The ymXX10 and ymXX20 are the power shift models. There are several different PTO hp models that run the power shifts. But the ym2002D that I have is just a plain old gear driven tractor. It dies have the crawl range which is a bit unique (and very rarely used). It even has a 10mm hex pin that blocks going into to crawl range. And even 3 gear in crawl is turtle slow.

Yep, that is correct. Xx10 and xx20 in our old tractors are Powershift models. I was just pointing this out cause of all the talk of hydro pumps and now powershifts. So your hydro pump can be bad or have a key sheared and your Powershift tractor will still drive. So this tractor even though the transmission runs off hydraulic power it's supplied by a separate hydro pump from your main pump.

 

[CoyPatton]

Yep, that is correct. Xx10 and xx20 in our old tractors are Powershift models. I was just pointing this out cause of all the talk of hydro pumps and now powershifts. So your hydro pump can be bad or have a key sheared and your Powershift tractor will still drive. So this tractor even though the transmission runs off hydraulic power it's supplied by a separate hydro pump from your main pump.

Not sure what this tractor is. My tractor is a YM2002D. It is nit a power shift model even if I was told it was. I must clutch to change gears and/or ranges.
But yes the 10 & 20 series would have a pump in the transmission and act somewhat similar to an automatic car transmission that and shifting between gears. That pump would indeed be separate from the hydraulic pump attached to the engine which runs your 3 ph arms and other items that you may add to your tractor such as FEL or top and tilt.

 

[California]

... 10 & 20 series would have a pump in the transmission and act somewhat similar to an automatic car transmission that and shifting between gears.

Just speculation here but I think Powershift is nearly identical to the small-car A/T's of that era, with the only difference being no torque converter buffering between the engine and transmission. (And no governor/speed sensor to cause shifts, only the shift lever for that). You let the clutch out which spins up the PS internal pump, this pressure engages a clutch pack (similar to a motorcycle clutch), and after this moment delay you have a straight mechanical connection clear from the engine to the wheels.

Additionally - I wouldn't be surprised if an A/T rebuilder looked at a disassembled PS and noted the internal working parts are the same actual parts as found in an A/T from Datsun, Subaru, or something. There's no reason why Yanmar would duplicate a complex and proven unit from scratch when it already exists.