# JD 400 Hydro Issue



## tom jones (May 6, 2020)

Hi people my this is first post, I bought this JD 400 GT not running with a busted PS hose for $100, been sitting around here for about 6 years. Started to work on getting running this week. Needed new starter, coil & relay to get motor going, but first bought pre owned PS hose from ebay & installed it. Once it was running I tried it see if it would move, nothing so figured she lost fluid from busted hose. I saw on this forum that some people use F Type fluid in these tractors, I checked dipstick nothing showing, so put 1 quart she started to move, the PS started working little glitchy also 3 point glitchy. Checked dip stick nothing so add another quart everything was better total 3-4 quarts sill nothing on stick but then everything working smoothly. I drove it around goes pretty fast in high gear all looked good. Started her this morning put her in gear and engine bogs down & dies. So I put in neutral she starts up try the 3 point lift kills motor, even the PS kills motor, so I let it sit for a while. Try again couple hours latter and everything is working again, but I'm afraid this may happen again and screw something up, don't think it's a fluid level problem but some valve sticking or clog somewhere. Tractor moves easily in neutral when pushed by hand no leeks anywhere that I can see. Not sure what to do next, if anyone has any ideas please message me, Thanks Tom


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## bontai Joe (Sep 16, 2003)

When you pushed it in neutral, did you release the hydro valve first before pushing? Because it shouldn't be easy at all to push unless the hydro is disengaged. I don't mean the neutral position on the dash, there is a knob that has to be turned out several revolutions to disengage the hydro. Sounds like someone has already disengaged the hydro making it easy to push. DON'T WORRY! I would continue to add fluid to the hydro until you see some on the dipstick. My 316 hold 6 quarts to give you a reference. I'm not familiar enough with the 400 to tell you where the knob is to tighten down and reengage the hydro. My guess is it's the black knob between your legs when sitting in the seat like my 316. Screwed down until hand tight would fully engage the hydro. Screwed up until it stops would fully disengage the hydro. Yours just might be somewhere in between.


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## tom jones (May 6, 2020)

Thanks for replying, I don't believe the JD 400 has the knob hydro release system, it has a Hi - Neutral - Lo selector lever on the floorboard for the 2 speed rear end, neutral releases the hydro. Thanks Tom


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## EdF (Sep 15, 2014)

Hello Tom,

Tractordata.com lists the JD 400 GT transmission fluid capacity at 5.5 quarts. So, if you've added 3-4 quarts, you have more to go (assuming it was basically empty). I would add till the fluid level shows up on the dipstick, but no more than 5.5 quarts.


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