Hydraulic leak - what to do?
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rScotty
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- Rural mountains - Colorado
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- Kubota M59, JD530, JD310SG. Restoring Yanmar YM165D
All good advice - especially the part about how to distinguish whether it is entrained air from running with too little fluid, or water that has gotten into the hydraulic fluid. Either way, it is probably time to drain the fluid, change the filter and put in new fluid.
But first you obviously want to see if this is a leak that can be fixed by tightening the fitting and then adding fluid. That may well be the case.
To my eye that looks like a compression fitting - also known technically as a JIC fitting. Google it. Compression fittings do not have O rings or thread sealers. They rely instead on the shape of a cup/cone fitting between a hard cone and softer cup that are forced together by the pressure of the screw threads. This is really the best of all types of pressure fitting and is preferred for many applications.
It isn't unknown for them to loosen up from vibration, and sometimes they will fail from being so overtightened that some part of the mating sealing suface or the the outer nut itself will develop a hairline fracture from over-tightening.
To tighten it right is easy, you MUST be sure to use two properly fitting wrenches so that one will hold the longer section of the fitting stable to keep it from rotating - that's the part to the left in your photo. Then you use the other wrench to turn the part that is more to the right in the illustration. All (well, almost all) fittings and bolts tighten the same way i.e. tighening is considered clockwise if all the tubing didn't exist and you could you look at the fitting from the end.
Tighten it until you feel that all the play as been taken up, and then give it some compression by turning it another 1/8 to 1/4 turn. No more than that. It should seal then.
This type of compression joint can be successfully reused several time if it is carefully assembled and the mating surfaces kept clean before tightening.
Good luck,
rScotty
But first you obviously want to see if this is a leak that can be fixed by tightening the fitting and then adding fluid. That may well be the case.
To my eye that looks like a compression fitting - also known technically as a JIC fitting. Google it. Compression fittings do not have O rings or thread sealers. They rely instead on the shape of a cup/cone fitting between a hard cone and softer cup that are forced together by the pressure of the screw threads. This is really the best of all types of pressure fitting and is preferred for many applications.
It isn't unknown for them to loosen up from vibration, and sometimes they will fail from being so overtightened that some part of the mating sealing suface or the the outer nut itself will develop a hairline fracture from over-tightening.
To tighten it right is easy, you MUST be sure to use two properly fitting wrenches so that one will hold the longer section of the fitting stable to keep it from rotating - that's the part to the left in your photo. Then you use the other wrench to turn the part that is more to the right in the illustration. All (well, almost all) fittings and bolts tighten the same way i.e. tighening is considered clockwise if all the tubing didn't exist and you could you look at the fitting from the end.
Tighten it until you feel that all the play as been taken up, and then give it some compression by turning it another 1/8 to 1/4 turn. No more than that. It should seal then.
This type of compression joint can be successfully reused several time if it is carefully assembled and the mating surfaces kept clean before tightening.
Good luck,
rScotty
Tractor Seabee
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- Kubota BX25
On steel lines like those it is not uncommon for the JIC flare on the tubing, RH side on your picture, to fracture from vibration or catching on something. The flare is not the common 45 degree like plumbing stuff. Takes a special expensive flaring tool especially on steel tubing. The flaring process can/does stretch the tubing creating a weak point. Hydraulics are not a good subject for novices.
Ron
Ron
Friends, OP here. Just wanted to report that the tractor gods smiled on me and my trusty BX2200. This morning I got under the tractor to examine more closely the hydraulic leak coming from what I think are the FEL lines. And as soon as I laid a crescent wrench on one side, I discovered that the JIC fitting, where the fluid was leaking from, had thoroughly loosened. So I tightened it and fired up the tractor. No more leak. So I added about 1 3/4 to 2 gallons of Super UDT, which brought the level to the high water mark. I then mowed for about 45 minutes. No whining from the HST or leak from the JIC on inspection - and no Hansel and Gretel "bread crumb" trail on the grass.
Want to thank you all for your great help, and for saving me an expensive and embarassing trip to my local dealer.
David
Want to thank you all for your great help, and for saving me an expensive and embarassing trip to my local dealer.
David