Hitachi EX60G Gear oil leaks onto inside of sprocket as I'm filling planetary

[ExcavatorEX60]

Hello,
I just brought home my first excavator, an EX60G. Its been seeping oil onto the inside of the sprocket since it came off the trailer and continues to leak even when its not running. When I checked the planetary it was down and took a couple quarts but while filling it I noticed it was leaking rapidly, again on the inside of the sprocket. If its leaking while sitting and not running can this only be the floating seals?

I initially thought the leakage was hydraulic oil but now, as it leaks the gear oil I'm adding, I notice that gear oil smell. Could bad brake or other seals have forced the floating seal out? If so I should probably get to the other side soon.

The machine sat for 10 plus years in a damp forest in northern CA and the motors were packed in mud behind the cover plates so moisture around the floating seals may have been a problem, the motor case and and lines have a lot of rust.

Any advice would be greatly appreciated, I have good mechanical skills but minimal hydraulic experience so most of my understanding of the drive motor is from diagrams and other posts.

Thank you

 

[Diesel Dave]

Welcome to HEF Excavator .
If the brake or propel motor seals had pushed out the floating duo cone seal the hydraulic tank oil level would be very low as those seals would continue to leak. If the duo cone seal only just started leaking after you had moved the machine then I suspect the seal orings became very hard over time and or were stuck and tore when the machine was moved.
If you are trying to control downtime then you might as well do the other side now as well.

 

[92U 3406]

By your description I'm 99.9% leaning to the duo cone seal failing. If the motor seal failed it would have kept leaking and the final drive would have been filling with hydraulic oil. The final drive likely would not have been low unless the duo cone had failed near the bottom and oil was pouring out as fast as it was leaking in past the motor seal. Add in the fact you've identified the leaking oil as gear oil as well.

Either way you'll probably be pulling that final drive for repairs. You'll know more once you dig into it.

 

[ExcavatorEX60]

Thanks Dave and 92U its great to have experienced input on this. I would like to minimize the down time for sure, so Ill get 2x of all seals for the drive motors. I'm trying to figure out if the ex60-1 seal kits will interchange with the ex60G otherwise I have individual #s for the ex60G. Motor numbers are HMGB08CA which I see from another post is not the same as 60-1, but maybe the seal kit is?

Can I do this work without splitting track? With track in place if I slack and support it near the sprocket?

I have a brief project for it as soon as I can declare it leak free and instrumented, and get a seat in it, after that will have a less hurried pace.
Amazing machine it rained into the cab for 10 yrs but still the throttle stalk and seat riser freed up and work as new with a week of penetrating oil and nudging. Not a single one of the heavily rusted floor bolts snapped off! I declared the 35 yo corroded circuit board too big a project for the limited gauges and idiot lights. I'm fitting a cheap diesel boat instrument panel that is: 24v, low rpm tach, moisture sealed and prewired:

https://www.amazon.com/dp/B0BQJ4QQL2?psc=1&ref=ppx_yo2ov_dt_b_product_details

was $150 and I see they raised the price, thought we were going the other direction.

The electric system is nicely layered so the instruments appear to come off without any loss of running function except maybe the economy/power control. Ill add a big red trailer light in the cab for high temp and low oil pressure. As soon as I have a handle on the water temp and oil pressure, and the leaks fixed Ill put it to work for a busy few days, hoping Ive addressed reliability for now.

It has a sad history, the machine was tipped and apparently ran until a rod went through the block. The previous owner put a good used engine in, trailered it home and parked it, so could be 15 yrs of not running much, it indicates 3700 hrs. I chained it to a tree and squared the cab and still need to do the windshield frame so I can get the glass back in. It has blade and thumb and came with the 5' grading bucket and the 18" digging. I probably have 100-200 hrs of work for it in my life time and it was cheap enough to keep with the property for convenience and freedom from rental hassles. I'm shocked how well it pulls stumps and moves boulders, my back and tractor will last much longer. We are rebuilding after the fires on a rocky property with very little dirt. It will be used mostly for grading fill, moving boulders, hammering and grabbing logs/trees. I have a vibe plate and hammer for it as well but sourced from different places and will need adaptation.

A few questions:

Is there a way to add a hydraulic safety cut like a modern machine? I see how dangerous it is to get in and out while its running and hydraulics are live, but I'm not sure shutting it off is a habit Ill keep up.

There's a plug apparently to inspect the swing gear, should I be greasing the gear in addition to the zerks on the swing bearing or does the bearing grease spill over onto the gear teeth?

What quantity of grease goes in these parts? Till it oozes out on outside?

Similarly is there a drain under the swing gear to let out water that gets in? I haven't crawled that far under yet but don't see it in the manual.

The thumb action is interesting, it closes as long as I hold the switch closed and stops when I release it. However, on opening, once I've triggered it the thumb keeps going (even it I release the switch) until it hits the mechanical limit or I trigger it the opposite direction. It appears its always done this because its ripped the welds on the cylinder mount until the cylinder could bottom out. I think this was to allow the thumb to retract automatically but is it normal to run the ram into its hard limit repeatedly?

Thanks again for your advice and any responses to the above would be greatly appreciated as well.

 

[Dave Neubert]

You will have to split track then dissemble the final drive so you can get the hub off most likely you will find the bearing bad too

 

[92U 3406]

No way around it, track will need to come off.

Typically you want to put a little grease in each swing bearing grease fitting, rotate the machine about an 1/8 turn and repeat until you've made a full revolution.

The grease on the inside where the swing gear is really only ever gets changed if its contaminated in the real world. Usually you'll have to scrape it out into a bucket. Refill the tub enough so that the swing pinion gear is just slightly into the grease. Maybe 1/8" or so if I remember correctly. Just enough that a small amount will get squeezed up the gear faces as it rotates.

Operation/maintenence manual would give you the specific info, I'm just generalizing based on previous experience.

 

[ExcavatorEX60]

Well good to know going in so I can get staged for it. I see the link "tool", I thought it was implying a full interference press fit but it looks like theres a circlip retaining the pin. What sort of force should I expect? Can I likely drive it with a drift and sledge?

OK I will grease and rotate all the way at 1/8 turn or so.
Strange I think Ive reviewed all of the service and parts manual and don't see a word about greasing. I recall seeing it somewhere and I bet its the first manual I downloaded for 60-2. Unlikely Ive found all the zerks. Somebody replaced the bucket pins with greasless and it looks like it hasn't had grease there since, hopefully there are press in bushings there.

The drive bearings sound like a good idea to have on hand too. 400/side to reseal and bearings ouch, but I was expecting some seals and bushings when I bought it.

Got the windshield frame squared so hopefully the glass pops in, something really demoralizing about a windshield that's half ejected from its gasket.

Thanks again

 

[Diesel Dave]

ExcavatorEX60 said
“Is there a way to add a hydraulic safety cut like a modern machine? I see how dangerous it is to get in and out while its running and hydraulics are live, but I'm not sure shutting it off is a habit Ill keep up”
.
Not sure if your machine had a pilot shut off valve/ solenoid valve from the factory or not. Sounds dangerous for sure !
You could wire in and plumb in a 24 volt pilot shut off solenoid valve such as part # 4609630 .
It’s used on some on Hitachi ZX-3 and ZX-5 excavators and also D and G series Deere excavators.

 

[Diesel Dave]

ExcavatorEX60 said “ The thumb action is interesting, it closes as long as I hold the switch closed and stops when I release it. However, on opening, once I've triggered it the thumb keeps going (even it I release the switch) until it hits the mechanical limit or I trigger it the opposite direction. It appears its always done this because its ripped the welds on the cylinder mount until the cylinder could bottom out. I think this was to allow the thumb to retract automatically but is it normal to run the ram into its hard limit repeatedly? “
.
Sounds to me like the switch or the solenoid controlling the thumb open direction is intermittently sticking on. Check if there is continuous power or not at the thumb open solenoid.

 

[ExcavatorEX60]

That sounds good Dave, Thanks.
I see only the regular pilot valve on the EX60G but it does have a wire. That may be part of the fluid heating circuit control. Regardless I should be able to plumb a valve like you suggest to bypass the pilot pressure so nothing can activate. Maybe Ill start with the logic on a very new machine to make sure I understand the degree of disablement they are getting, I suspect they have worked this out to a fail proof or fail safe system by now.

 

[ExcavatorEX60]

Yes the thumb switch could be sticking its action is flakey even after I cleaned and oiled it. Its actually two microswitches taped together and it could be that one is normally off and the other is a toggle to give automated return, I wasn't that observant when testing it. Turned out that the plug terminal/tab at one of the fusible links was broken and discovering that got me away from the stick switch.

Ill get back in and test each one. Now that you have me thinking, I recall it clicks in one direction and not the other which I thought was unintended, but maybe not.
The thumb is the slowest motion by a lot so it could have been intended, but it sounds like that would be unusual. It looks like a retrofit kit.

 

[ExcavatorEX60]

Thanks for all the help here everyone, the feedback not only has valuable info but gets me thinking next steps.
Dave, I was able to use the AVS catalog you'd suggested in prior EX60 posts to cross 60G to 60-1 and get my drive seal parts ordered in time for Friday. Even though the motors are different it appears the motor seals are identical along with bearings, planetary and group seal.

 

[ExcavatorEX60]

I see two concerns for getting things apart on the drive motor:

1) How hard is it to drive the master track pin once I find that circliped pin?

2) The very large bearing nut wiith really high torque 360ft/lbs. I can make a spanner if I have too but would be easier to order one if there are cheap sources. I dont know this type of pin driver does it have a convention and common sizes or is this Hiitachi only?

 

[Diesel Dave]

I see two concerns for getting things apart on the drive motor:

1) How hard is it to drive the master track pin once I find that circliped pin?

2) The very large bearing nut wiith really high torque 360ft/lbs. I can make a spanner if I have too but would be easier to order one if there are cheap sources. I dont know this type of pin driver does it have a convention and common sizes or is this Hiitachi only?

1) If you have a snap ring retained master pin it was a tap fit in the master links when new. If necessary a bit of heat on the links will help get it moving.
2) IIRC the socket for the final drive bearing retaining nut was a shop fabricated tool. You likely wont need the tool when coming apart. A couple of sharp raps with a medium hammer and punch should get it loosened. Of course you will need the socket when going back together.

 

[ExcavatorEX60]

I found the pins and it looks like they have no circlip and are maybe a taper fit. They have drift marks on the protruding side and are recessed on the other side. Ill try a bit of pounding today. Torch set is an hr away and I'm working out of my van so Ill try really hard with the sledge.

I've used the punch drift method and your comment confirms I can probably get enough angle on it. I have an adjustable pin tool coming, one thats used for flange nuts on hydraulic cylinders, if it fits may save me a few hrs in a friends shop.

Thank you

 

[92U 3406]

Take the shoe off on either side of the master. Makes for easier access.

 

[ExcavatorEX60]

Ah! now I don't have to find that extra long drift. I owe you an hr or two.
With that clearance I could probably strap a hydraulic jack on it, but Ill start with the hammer.

Thanks

 

[ExcavatorEX60]

Anyone know what size or standard of the orings for the drive motor pipes? The pipes for forward and reverse seem to be roughly 3/4" and have a flat face with an oring groove.

The return looks to be a taper flare and no oring.

The brake piston orings are definitely shot, haven't seen the floating seal yet. Fortunately no signs of running without oil everything was wet and no filings. Well see when I get to the bearings. Best scenarios is after sitting for 10+ years the brake pistons failed and just dislodged the floating seal?
My new brake orings are not green, is that that a viton or something special for the sliding aspect? Will I ok with a regular buna type there?

The master pin was an awkward swing and wouldnt budge and the pin spacers were missing so I decided to make that a seperate project. I ran the whole track off with some 2by4s about 5 mins after 2 hrs of flailing. Hope it goes back on OK.

 

[Diesel Dave]

ExcavatorEX60 said “Anyone know what size or standard of the orings for the drive motor pipes? The pipes for forward and reverse seem to be roughly 3/4" and have a flat face with an oring groove.”
.
The ORFS style o-rings on the (2) motor supply pipes should be a -12 size.
The Deere part # T77858

 

[ExcavatorEX60]

Thank you Dave,

I don't understand the knock pin. Do I drive it deeper and below the nut so the nut can turn?
Its already recessed below the top face of the nut a bit but. Feels like its a very tight fit.

Gears all look very clean and unworn, no sign it ever ran low on oil.

Realized today that they sent a seal kit for EX60-2. So Im waiting for parts again.