Flushing hydraulics on a Jinma 254

[odd]

I want to flush the hydraulics system on my Jinma, but I like to be sure of the procedure before I begin.

Can anyone verify, and give some answer to my questions?


Flushing hydraulics, Jinma 254:

1. Drive tractor, to heat up the hydraulic fluid.
2. Drain reservoir.
3. Pour in 2-3 liters of kero.
4. Start tractor, and turn wheels
QUESTION 1: How much (how many times..?)
5. Run hydraulic lift
QUESTION 2: How much (how many times up and down?)
6. Stop tractor, and drain reservoir
7. Fill reservoir with 2-3 liters of AW32
8. Disconnect return lines.
QUESTION 3: Where are these return-lines located?
9. Start tractor and drain from return lines into bucket. Turn steering to drain hydraulics for servo.
10. If necessary, do 7,8 and 9 again.

QUESTION 4: I am afraid to destroy my hydraulic-pump. I suppose it will run dry when I drain with engine running, and return-pipe disconnected. comments??

QUESTION 5: How can I be sure that all kero is out of system?

I like to be sure before I begin....

 

[greg_g]

Dunno where you got these instructions, but rather than address each question - I'll simply list the steps I took with my two JM254s.
1. Run tractor and exercise hydraulics to thin fluid before draining
2. park tractor with nose uphill
3. shut off engine, drain hydraulic fluid (an extra long neck funnel helps get more of it into the bucket and less on the tractor).
4. reinstall drain plug, remove fill/vent plug, add 2.5 GALLONS of kerosene to reservior. Reinstall fill/vent plug.
5. Start tractor, drive several figure 8s to flush the steering while raising and lowering the three point hitch to flush the rest of the system.
6. repeat steps 2 and 3. I pass the draining fluid through a screen mesh to catch the big chunks, permitting possible reuse of the kero for a 2nd flush if necessary.
7. If the consistency of drained fluid indicates, repeat steps 2 through 6.
8. refill with 2.5 gallons of hydraulic fluid suitable for your climate.
9. repeat step 5
10. top up hydraulic fluid as required.
11. double check the level in one week.

If you really want to be **** about it, you could manually purge the steering hoses/cylinder. But kero and hydraulic fluid have different specific gravities. They will soon separate, the kero floating to the top. It then evaporates fast enough so that I do not find the purge step necessary, and is the reason for step 11.

You should also check the condition of the hydraulic suction screen, but that's an entirely different procedure.

//greg//

 

[RonMar]

I found that a cheap generic fuel filter works well for filtering the crap out of the kero for future use for cleaning. these filters typically filter to between 40 and 70 micron so it will get a good portion of the junk. Napa part numbers 23001, 23002 and 23003(1/4", 5/16", 3/8") are all under 2$ at my local NAPA store. I also removed the hydraulic strainer as greg mentioned and looking down through that hole in the top of the resovoir I discovered a lot of fine metal shavings in the bottom. With the front of the tractor elevated, I found that a piece of rubber hose about 1/2" OD could be press fit into the drain hole to allow fluid to run directly into a catch can without spilling. I used an old windshield washer pump that I had lying around and drawing kero from the can through one of the filters mentioned above, I was able to pump kero through the resovoir to wash that metal toward and out the drain. I ran the kero from the pump into a piece of small diameter aluminum tube that I could bend. This allowed me to reach back into the corners from the access hole where the strainer fits through. Kerosene is pretty tame but you of course want to keep away from open flame or any other sources of ignition while working with it.