Changing Hydraulic Oil
 

I'm hoping that some of you guys can give me some advice on how to change the oil on my Leimbach Excavator.

I took some pics of the hydraulic system and labeled each connection to make this a little easier:

http://i172.photobucket.com/albums/w...ilChange01.jpg

http://i172.photobucket.com/albums/w...ilChange02.jpg


1:
2:
3:
4:
5: Reservoir Breather
6: Reservoir Breather
7:
8:


To, it looks like fluid is pumped from 2 into the filter at 4, out of 8 and into 7 to the value body.... then out of 3 and back into the pump at 1. !!!

My questions are:
A. What line do I remove and put into my new fluid?
B. Do I need to service the filter?
C. I assume I also remove the reservoir and put new fluid in

Or, a better way, is how do you change the oil in a machine like this?

Re: Changing Hydraulic Oil
 

1: return line
2: pressure line

Don't disconnect any lines.

Remove the right side body, two screws in front, three in the back. Lots of wires connected to main switch, handle with care laying rightside body out of the way on a soft cloth.

Unscrew fitting #5 or #6.

Turn on radio, model & pump; raise boom to the top of it's travel.
Shut off pump.
I use a 12ml plastic syringe (10 cents @the ag store) with a 2inch long 14 guage (maybe bigger) needle to suck the oil out of the reservior.
Activate stick control on tx for bucket and by hand manually curl bucket back & forth to force the oil out to the reservior.
Suck used oil from reservior with syringe.
Do the same thing for the stick cyl, then suck out oil.
Lastly, the boom cyls, exhaust the oil out and suck with the syringe.
Now stuff some tissue under the reservior and twist & pull the reservior off the pump.
Wipe the inside clean with mineral spirits & tissue.
Using a wrench on the top of filter, unscrew the cap and remove the porous brass filter.
Wipe out filter can with mineral spirits soaked tissue.
Clean porous filter in a glass of mineral spirits. Blow dry with pressurized air.
Put filter back together.
Wipe a little bit of lithium grease on inside edge of reservior can and twist & push it back on pump.
Using a new syringe, load with fresh oil & fill reservior.
I like to use a 7.2v batt to run the pump slower while refilling the hyd system to keep oil foaming to minimum.
Turn on pump, raise boom, add more oil. Activate stick one way, add more oil, go back & forth a few times, add more oil.
Do the bucket.
Then do the boom with stick/bucket hanging over the table.
Replace fitting #5 or #6.
Replace the rightside body correctly.
Done.

Re: Changing Hydraulic Oil
 

Very good Joe

Re: Changing Hydraulic Oil
 

Thanks a TON Joe !!! I knew you'd be all over this one. I was going to PM you, but figured everyone may be benefit from it.


Looking forward to getting the machine serviced and ready to go!

Re: Changing Hydraulic Oil
 

wow Joe!! you know your stuff!

Re: Changing Hydraulic Oil
 

Great thinking Rod. http://www.scale4x4rc.org/forums/ima...ilies/nice.gif

Re: Changing Hydraulic Oil
 

Here is another way to get your oil out of the tank and filter fast without having to use a syringe. Just take the screw out of the filter and add a nipple with a hose attached, put the hose in a cup. Turn on pump and within a few seconds they are empty...
http://i124.photobucket.com/albums/p...2/pump2002.jpg

Re: Changing Hydraulic Oil
 

I figured I'd share my experience here!

I'm glad I changed the oil! Mostly for peace of mind to know when it was done last and when it has to be done again. Didn't take much time at all. Here is a comparison btwn the old and new oil!!!:

http://i172.photobucket.com/albums/w...ilchange03.jpg

http://i172.photobucket.com/albums/w...ilchange04.jpg

The syringe I picked up worked great to fill the reservoir, its made by Chefmate, its a "flavor injector," got it for $3 at my local target store. Highly recommended for filling the system! I had to use a smaller syringe to draw the fluid out.

How often should I change the oil in the machine?

Re: Changing Hydraulic Oil
 

When it gets duty, you do have a sight glass. Ed

Re: Changing Hydraulic Oil
 

Guys just a little suggestion. If the oil comes out of your equipment looking that bad your looking for big trouble down the road.
That oil is the life blood of any hydraulic system big or small. The dark coloring is metal fillings from your pump eating it's self up.
Never, never leave it till it's that color. Cleanliness is of the utmost importance!.
You should change it at least once a year and maybe more if there's allot of dust in the air.
Even pouring oil strait from any container is bad. It should all ways be filtered on the way into the tank. Had to replace a pump once, because there was plastic that somehow made it into a brand new container.
The oil that came out of Gregs machine is the way you want to see it in the container, still looking pretty clear, That way your pump and cylinders are going to be happy. Any other way and the grit is tearing up your o-rings and the pump gears even if you have a filter.
Rob

Re: Changing Hydraulic Oil
 

The oil in my excav is changed every couple wks & looks just like Rod's sample everytime.

The 15bar pressure & aluminum cylinder barrels are the two main reasons for the oil darkening so quick.

My dozer, track loader, wheel loader all run @10bar & the oil color is much cleaner/clearer after six months.

Steel cylinder barrels would help so much to maintain oil color/quality.

A couple wks for me is about 15 to 20hrs of intermitent use.

Re: Changing Hydraulic Oil
 

That is a story and a half Rob.:o It took me two hours to get the oil in that hyd machine to look that clean, and half a litre of oil. I unhooked all the cylinders and manually sucked oil in and out of them to get them clean. Changing the oil each time I cycled them.
I thought I better get it done before you seen how dirty the oil was. :D
greg

Re: Changing Hydraulic Oil
 

Now I know for sure I don't have enough time for this hobby!! ;)

I'm kinda new here but seems like this ought to be a sticky.

Joe

Re: Changing Hydraulic Oil
 

Done.

Travis

Re: Changing Hydraulic Oil
 

I learned something today !:rolleyes:
Where I took the bolt out from the filter, it is a place to hook up a line to a pressure gauge to see how many bar you are operating the pump at...

greg

Re: Changing Hydraulic Oil
 

That's correct Greg, I connected mine there to when set the in my hoe to 15bar.

What do you have your pumps set to?

Re: Changing Hydraulic Oil
 

Hello Guys, THANK YOU for this info its helped me alot, Please can you tell me is it possible to turn up the pump on the wedico cat 996 G, i have just chech it & it running at 9 bar + when I operate it it is running very slow like when I lift the bucket it goes down to 4 bar and lifts extremley slow Please is is possible for some one to tell me what I'm doing wrong, Thank You Again.

Kind Regards Jo ( Wales UK )

Re: Changing Hydraulic Oil
 

you can turn it up but i would not go too far like 12 or 13 it is more wear and tear on your pump plus the oil will get dirty faster what size is the hose on your machine;)

Re: Changing Hydraulic Oil
 

Hi Thanks for the reply, Please is it easy for you to tell me how to turn it up what skrew it is ect, like you ay I dont want to go to much 12 max but I think 9 is a little to slow the tube is what came with it as a kit from wedico I'm not sure of size 3 or 4mm, I'm really no tech type of guy I just really enjoy the playing & operating the the models, Thank you again for your help & time. Regards Jo

Re: Changing Hydraulic Oil
 

yes jo to turn it up look on the side of the pump and there is a black allen screw you need to undo this but be carefull as when you take this screw out the oil will come out you will have to lay the machine over so the screw is facing up when you take the black screw out behind it there is a tork screw i think #6 and if you turn it clockwise you will turn up pressure counterclockwise lower pressure just turn clockwise 1/4 turn and put black screw back in and check your pressure and tighten the tork screw to pressure you want also if your machine is older one it probably has 1.5mm id hose newer ones have 2.5mm id hose that will make it slow too thanks neil