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Turret coolant seal

Andrew M.

Aluminum
Joined
Jan 16, 2006
Location
Atlanta , GA
Turret coolant seal

I would like to ask You guys master Mazakers opinion on a coolant leak on my QT15.
The leak come from behind the turret at the point were the line in the casting align with turret selected tool.... pretty much the point, i think , were the coolant leave the casting to enter the turret. In front of My face so to speak.
I’ve never been in the turret so far, and lacking an exploded view of it , i imagine some sort of seal been there, maybe spring loaded to release as the turret is unlocked and seal back as the selected tool is in place.
There is still plenty of coolant going to the tool, but, the thing is annoying at this point, and i would like to take care of it before the situation worsen .
How hard is going to be to gain access to the back part of the rotating turret and correct this problem.

Thank You in advance
 
Getting the turret off is easy. Pop the cover off in the center that has the tool #s on it. UNCLAMP the turret, and take off that big nut, you might need a spanner of some sort, I just milled one up, or you could use a screwdriver and a hammer. Then it comes right off. Take you maybe five minutes(at least once you get good at it).

It is heavy, so an engine hoist or overhead crane. I'm going to guess they are 70-100lbs, but why risk dropping an expensive piece of equipment.
 
i say just the opposite
comes off as described but it's a pain in the ass
and it ain't cause i'm some newbe at this i've pulled more turrets than carters got pills
problem is the spline shaft kind of sucks lining up
and as stated it's heavy
iv'e had them fly right on and i have spent 25 minutes and lost 3 pounds from cusin'
you just never know
my mamma said life is 50/50

but none of that maters
if you want to fix that leak on a qt15, the turret has to come off
other machines it's possible to get at seal without pulling turret
but not a 15

while your in there pull the plunger out and clean the crap out of spring
 
Yep, on a QT15 (or QT20) the only way to rebuild the coolant plunger seals is to remove the turret itself.

You need to order the main coolant seal and plunger seal from Mazak. Get the P/N's from your mechanical parts manual.

The coolant seal is a "doughnut" machined from a type of hard plastic. This piece presses inside the face of the brass plunger, and rubs against the backside of the turret at all times. The plunger follows the turret out when unclamping due to the spring mounted at the back of the brass plunger.

The brass plunger has a seal around it's od, to seal coolant from escaping between the od of the plunger and the hole it's mounted in. THIS SEAL IS NOT AN O-RING, but a metric-spec shaft seal, made so that coolant pressure makes the seal work better. Using a standard o-ring here will result in leaking again in no time at all. Ask me how I know....

The brass plunger is mounted inside a brass sleeve inside the turret-box casting. This sleeve has a setscrew engaged in a groove to hold it in place. Once the setscrew is out (there may be a locking set-screw on top of the one against the sleeve), you will have to wiggle and cuss a bit to get the plunger and sleeve assembly out of the hole.

The seals are cheap, but Mazak charges a mint for the brass plunger.
 
when you get it apart use some sort of epoxy to glue it back in. i think once you get the turret off you'll find the seal just laying there in one of the crevasses behind the turret or it will just fall out. i had to do it on a slant turn 50
 
Thank You all guys,
Greg, Now I've got a clear view of what I'll find in the back of that chunk of metal.
Tomorrow I'll look for the parts #'s and call Mazak for the seals, as soon as I get the parts Ill take the turret out and make a new plunger to match the old one.
The way You tell me is working, touching the back of the turret at all times, it surely has some side wear ( Egg shaped ) for the drag, and of course will be foolish putting back new seals on an old plunger just to see theme worn out shortly thereafter. Wander if the side plunger seal looks like one of the seals in this page.. http://www.alliedmetrics.com/ucups.html
I was thinking about making a wood cradle from the tailstock bed, to past the turret bottom, resting on the sheetmetal right below the flood coolant port, ( sort of what I use on my old LeBlond to change chuck) that should also help for the reassembly.
Wipping Boy, ThankYOU Sir! for the colorful procedure description, Looking at the size of that thing, and the tight quarters you have to work in, a real knuckle and a** buster. You gonna actually need few of them Carter`s pills before and after the job ( Lately they must have switch Him to some Potent stuff )
I will keep You guys posted, maybe with some pictures if I get around learning how to post them ( No video with audio !!!)
 
the seals don't look like those cups
there a solid piece of urethane(maybe)
3/4" od 1/4 id and maybe 400 thou. thick
yup
a tiny little rubber donut
 
Hey Andrew,

Yeah, the side plunger seal looks like one on the website in your post. It is critical to install this seal correctly, with the opening facing the tailstock, or pressure side of the coolant flow.

Wippin' boy is referring to the end seal, actually machined from hard plastic.

I use a 2x6, directly under the turret, resting on the z-axis way cover in back, and the door rail in front, to create a platform for the turret to drop down onto. You can use the slant of the way cover to raise and lower this board as needed to get under the turret. Once off, just carefully slide the turret towards the front, using the 2x6 as a bridge.

You can lift the turret by hand. Just make sure you have a good hold, make sure you keep it close to your body, and have a workbench right there to set it on. Without the boring bar blocks or any tooling, I would guess maybe 75-100 lbs.

Greg
 
Old thread, but it got me through the seal swap today and it's still good info.

Question- after reinstalling the plunger valve with new seals I'm getting no coolant from around the valve body, but with the turret removed (so the valve should be shut) I'm still getting pretty good leakage from the brass valve seat.

Is this to be expected, or should it seal tight? If it needs to seal tight should I lap the two brass seats together or what is the best way to correct this?
 
while the turret is off make sure you check the coolant porting for clogs. have found lots of crap stuck in the turret itself.

Doing that too. I have all the plugs pulled, now I'm thinking about the best way to clean them out. Wish I could rig it up to circulate cleaner, but I don't have fittings on hand to do so.
 








 
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