JD 410 Slow hydro

ChrisB · Sep 7, 2008

I have a '79 JD 410 that was open (tranny cover off) for a couple of years to replace the rear end. Got her back together last year. Running good, until the past week or so. I have changed the hydro oil once since I put new oil and filters in the machine apon putting the machine back together.

Now it seems I am losing power and speed on the hydraulics when the machine gets warm. Almost to the point to where I cannot lift a bucket of dirt when the machine is hot.

I did learn last winter that I had some water in the fluid last winter. I thought I had gotten it all out when I put the new filter and oil in this spring. No luck.

Pressure is fine at 2350 and machine moves fast when cold... just gets worse when warm.

Should I just do the filters and oil again, or should I look elsewhere?

Thanks in advance.

Roy Suomi · Sep 8, 2008

I have to assume you have a service manual for this machine....Put a gauge into the reverser control valve..If pressure is pretty constant from idle to 2000 rpm's within 25-35 lbs..It should read about 135 in forward and reverse..If it reads way low at idle and near spec. pressure at 2000 rpm's , I'd check the filter relief valve in the reverser housing...Another problem might be the destroking solenoid on the hydraulic pump is defective ..Deere has a plug that takes the place of the solenoid on the pump..If it works ok after installing test plug , then the solenoid is bad..

ChrisB · Sep 8, 2008

Hi Roy,

Thanks for the reply. I have the manual and have done the items you suggested before under your guidance. Am I correct to assume that you feel the above would be related to the machine getting warm?

I will get on it. Hydro main pump is only about 4 years old but the destroker is the same old one. Last year, under your guidance, I took great care in taking apart the reverser circuit, cleaning it and replacing all the gaskets (I was trying to find a hydro leak that left me with no pressure) so is it safe to rule out the reverser?

Would I not just need some sort of pipe fitting to plug the destroker?

Thanks again!

Roy Suomi · Sep 8, 2008

Don't assume that the reverser is beyond scrutiney..Check the pressures..Deere has a plug that fits that hydraulic pump as an alternative to the stroke control valve..This plug makes the system start pumping oil as the engine is cranking to start..Sometimes causing a sluggish start or no start at all..

ChrisB · Sep 8, 2008

Understood and will do. I only wish I could leave the gauge on the reverser. Do dangerous of a place to leave it. I leave the gauge on the pump and find it handy.

I have the electronic destroker and if memory servers me correctly there was a way to bypass it completely. Although I might be wrong. I will check and report back.

In your experience I am assuming that you do not believe it is dirty oil and clogged filters as I had first thought. Would it matter that the slow down in hydro seems pretty consistent ? By that I mean it seems to be gradually over the same period of time no matter what.

Regardless I will check the above items and report back.

For what it is worth, with prices the way they are, I have been using the cheap hydro from the auto parts store here. I cannot imagine it would make that much a difference. JD dealer wants $82 a bucket here.

Roy Suomi · Sep 8, 2008

I usually run a hose up to the rops with the gauge ty-wrapped to the rops upright..That way I can actually watch the gauge while I'm running the machine..Any oil will work as long as it's for hydraulic/transmission application..You changed the oil and filters before , didn't you??If the oil is that nasty , by all means change it again...You should probably figure out where the water is coming from..Maybe shifter boots ??

ChrisB · Sep 8, 2008

Roy,

The transmission cover was left open for a couple of years as well as both haves of the rear end. While they were covered somewhat I know it was not a perfect situation. After I got the machine button upped I must of ran 100 gals of hydro in and out of the machine before finding the actual leak that occurred right after getting the machine back together. That was all done with new filters in it.

Since she was running I put about 15 hours on her and replaced the oil and filters again. Now she has about 30 hours more on her since the last change.

Would water in the system cause the issue at hand? When water is cold would it not be acting somewhat like hydro until it got hot and became a gas?

Like a fool I did not let the last hydro sit and see how much water was in it (I used it for heat) .

I will still check on the items you mentioned above, I just ran out of daylight today.

sonicsebas · Oct 8, 2009

ChrisB, Did you get this solved and can you enlighten me as I seem to have your same problem. Thanks, Will

(quoted from post at 20:50:08 09/07/08) I have a '79 JD 410 that was open (tranny cover off) for a couple of years to replace the rear end. Got her back together last year. Running good, until the past week or so. I have changed the hydro oil once since I put new oil and filters in the machine apon putting the machine back together.

Now it seems I am losing power and speed on the hydraulics when the machine gets warm. Almost to the point to where I cannot lift a bucket of dirt when the machine is hot.

I did learn last winter that I had some water in the fluid last winter. I thought I had gotten it all out when I put the new filter and oil in this spring. No luck.

Pressure is fine at 2350 and machine moves fast when cold... just gets worse when warm.

Should I just do the filters and oil again, or should I look elsewhere?

Thanks in advance.

JD 410 Slow hydro

ChrisB

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Roy Suomi

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ChrisB

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Roy Suomi

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ChrisB

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Roy Suomi

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ChrisB

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sonicsebas

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