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hydraulic fluid leaking into coolant tank

zschary

Cast Iron
Joined
Oct 5, 2012
Location
Dallas TX
need some help.. . does anyone have a trick to find a hydraulic leak.. I noticed i was losing fluid and noticed some in my coolant.. here are shots of where i believe it must be coming from, i got rid of some around the fittings.. Looks like something has been leaking slowly and blowing everywhere in here.. Also.. it can drain right down into the tank..
i figure there are lines going into the spindle brake, the spindle and these big lines all "seems" tight..
ideas for me? what else would run off hydraulic fluid here? thank you
 
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The rotary union for the chuck actuator doesn't have any seals. It has a drain, usually clear vinyl hose. If that drain is kinked, blocked, goes down and then up or undersize from the factory your chuck actuator will spew a mist of hydraulic fluid as the oil heats up and more bypasses the rotary union.

When the spindle is running you should NEVER see oil back up in the drain. It should run freely down that hose and maybe fill 50% of the hose volume. If the hose is old and stiff and you can't see inside it anymore replace it. If the hose is say 3/4" hose and it kinda looks like 1" hose would fit fine, definitely step up to the larger hose.
 
Looks like a lathe? How old? Is the drawbar cylinder leaking excessively? I believe they're designed for the hydraulic fluid to leak a little and that drains back to the tank. If that's getting excessive or spraying because of a bad seal, it could be coming out around the chuck and into the coolant side of things.
 
The rotary union for the chuck actuator doesn't have any seals. It has a drain, usually clear vinyl hose. If that drain is kinked, blocked, goes down and then up or undersize from the factory your chuck actuator will spew a mist of hydraulic fluid as the oil heats up and more bypasses the rotary union.

When the spindle is running you should NEVER see oil back up in the drain. It should run freely down that hose and maybe fill 50% of the hose volume. If the hose is old and stiff and you can't see inside it anymore replace it. If the hose is say 3/4" hose and it kinda looks like 1" hose would fit fine, definitely step up to the larger hose.
there are definitely chips obstruction this hose.. i will clean them out.. but still if oil is getting down there does it point to a seal? should oil be going down this hose?
 

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Looks like a lathe? How old? Is the drawbar cylinder leaking excessively? I believe they're designed for the hydraulic fluid to leak a little and that drains back to the tank. If that's getting excessive or spraying because of a bad seal, it could be coming out around the chuck and into the coolant side of things.
it is a lathe.. its an 2005.. where is the seal? how big a deal is that to replace? how would i know for sure? I appreciate the help on this
 
there are definitely chips obstruction this hose.. i will clean them out.. but still if oil is getting down there does it point to a seal? should oil be going down this hose?

That's for coolant. The other hose. It's in your picture.
 
it is a lathe.. its an 2005.. where is the seal? how big a deal is that to replace? how would i know for sure? I appreciate the help on this

There is only one seal. You will get hydraulic fluid leaking inside your spindle if it is bad. Pretty obvious.
 
it is a lathe.. its an 2005.. where is the seal? how big a deal is that to replace? how would i know for sure? I appreciate the help on this
In your second Pic that green hose Is not a Hydraulic drain back. That is a coolant drain back. There should be a hose In front of that. That's the one your looking for.

Garwood beat me to it.

And this thread Is of particular Interest to me. I have the same problem that I haven't been able to locate on a Mazak QTN200. For one the machine is always so busy I havent had the time to tear Into It. I suspect It's In the Turret, But as deep as I can see and feel without tearing Into It It's dry.
 
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Hydraulic oil coming from the spindle end of the lathe usually ends up on the floor.

Hydraulic oil in the coolant tank usually is coming from the tailstock or the turret.

If you said what actual lathe it is it might help.
 
ok.. i see it.. here is a pic.. Two spindles y axis etc.. i have never been in there.. i am thinking you mean the seal under there has failed or a clog in that hose then draining into the coolant through the other hose?.. Tomorrow i will take that bottom sqaure plate off and inspect the hose, it does seem like its wet there.. we are talking about the seal right there correct? Other side of the lathe seems dry, where the sub is and turret
 

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ok.. i see it.. here is a pic.. the lathe is a ROMI E320y Two spindles y axis etc.. i have never been in there.. i am thinking you mean the seal under there has failed or a clog in that hose then draining into the coolant through the other hose?.. Tomorrow i will take that bottom sqaure plate off and inspect the hose, it does seem like its wet there.. we are talking about the seal right there correct? Other side of the lathe seems dry, where the sub is and turret

Re-read post #3.
 
thank you .. is there a specific type of dye for this? i just went through this on my car ac system.. The hydraulic tank is big, just pour some in there? thank you
I recently dealt with a spindle oil leak, knew it was coming from the spindle chiller unit but couldn't find it.

We bought "leak finder LF2008", says its for automotive oil systems but spindle oil and hydraulic will work too.

Bottle said 1 ounce for your automotive oil. Spindle oil tank is maybe 5 gallons on that machine, so I started out with 2 ounces which happened to be enough. It was very noticeable with the dye. Doesn't take a ton. Oil was leaking from a pump gasket and running down the inside of some insulation.

get a good uv light, maybe 30$ or so and good reviews. Don't get a harbor freight cheapo. They do work but the expensive one is way more visible.
 








 
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