Hydraulic Filter Change
T all who have ventured into hydraulics...
A year ago I bought a 1996 Kubota KX75UR grey mkt machine from a dealer in Alabama. It is a 18,000lbs 1996 Hitachi EX75UR-3 with a 54hp Nissan diesel with an orange paint job. Clean moderate hours (3800hrs) and in phenomenal condition. It has become an invaluable asset to our 20 acre Hurricane Katrina ravaged wooded lot.
The other day the blade control cable finally gave way. Lucky I was able to find a Deere shop that was more than helpful locating the part. As I was investigating I decided to look into changing out the hydraulic filter per Deere recommendation. They made it sound easy. This is where I need some help.
First, assume I know absolutely nothing about changing hydraulics...which is probably the case.
Second, there are no manuals for this machine available and I am shooting in the dark.
I was able to locate two filters. one small one near the hydralic pump and another long cylinder in a what seemed to be a high pressure reservoir. I took down the #'s and topped off the reservoir with what little hydraulic fluid I lost to elimate as much air as I could and resealed the plates and encasements. I did find the small filter at NAPA but the long high pressure reservoir filter will take more work to find.
I fired her up. The machine responds the same with no jerking and same speed as before but now have a hissing in the hydraulic lines.
1. Is there an absolute do's and don'ts to hydraulic filter change.
2. What is the type hydrauic fluid to use on this size machine. The guys at the shop said to just use what viscosity in th emachine already. Which turns out to be Universal hydraulic/transmission fliud.
3. Will the air eventually purge the system? I assue the hissing is incidental air from accessing the filter reservoirs.
4. Any threads or good web site on this procedure.
5. Any feedback? thoughts? Need more info?
If it is air, it will gradually work it's way out. You did use all new seals when you changed out that filter, right? It's always a good idea to exercise a machine right after fluids and filters have been changed. You purge air out and get oil working thorough the system, which helps to detect leaks or other little problems. Also, the operator doesn't get a surprise when he comes in on the next shift and fires that puppy up.
After working it a little, shut it down in the proper position and recheck the fluid levels. Most excavators have a specific position that the boom and bucket must be in when checking the hydraulic oil level. If you do not have a manual, and no one has told you what that position is, how do you know for sure that the oil level is correct? Better to find out soon unless you already know.
You really ought to get a manual on the machine, or have the dealer print out a copy of the section dealing with the filter change procedure. As a used machine, you really have no idea that the filter was properly installed before you bought the unit. Somebody before you may have reassembled it wrong or missed putting a seal in, or maybe placed a seal in the wrong place. If you assembled it the way you found it, it could still be messed up. I have found many a machine with wrongly installed filters or the wrong filters altogether. Better to not take a chance. You need to get a spec sheet on the proper fluids for your iron too.
I'm also assuming that you marked the filter or the housing with the date and hourmeter reading when you changed it. Or, at the very least, you noted the date and hours in your equipment PM history.
Good info Joe
Sounds like I stumbled along okay with the parts and the air will make its way through. I'll need to get with the Deere shop and get my eyes on a manual. I have some japanese friends that have helped me out with the kanji in the cab.
I'm trying to figure out how to post a picture or attachment. Hope to show you what I'm digging in.
I've sort of given up on Napa for parts. They are good parts, but it seems that they are out of stock for what I need much too often, of they give me the wrong part. ABC has been allot better. All my filters are now coming from them, as well as anything else that I need that they sell. Some stuff still comes from the dealer, but ABC is much cheaper then them if they have it.
The air in your lines from the filter should have worked it's way out fairly quickly. If the sound persists, and it sounds like it is, I'd remove the filter and check to make sure it's the exact one that you need. Do you still have the old one? Did you check them real close to make sure?