First time diy fluid change

dickhob · Dec 4, 2019

I have a Yanmar sc2400 with 980hrs. I am very much a novice at maintenance.

I froze the cylinder pin of the bucket (front) side of the FEL and had to remove the cylinder to have the frozen pressed out and a new pin made. On removal of the cylinder I lost most (all) of the hydraulic fluid from the cylinder.

I reinstalled the cylinder and reconnected the hoses. The bucket rotation worked but not well. Seeing as I was due for a hydraulic change I read up on how to change the fluid. I changed the fluid today following instructions as I understand them. I let the fluid drain for 30+ minutes before adding fresh fluid and filter.

I started the tractor and followed the low/high 40 second rpm startup several times. Both the FEL and 3 point hitch work, but the bucket rotation is still not where it was- very slow and 都pongy?

Also, the max rpm I can get is 2600 instead of the 3500 before the change. There are no leaks I can see.

Will these problems go away with use as the fluid purges air from the hoses or is there something I still need to do? Any help is greatly appreciated.

Thanks
DickHob

RNeumann · Dec 4, 2019

So it may still have a bunch of air in it. Open center hydraulics will self bleed the air out of the valve but not the ram. Cycling the ram several times can get most of the air out. And depending on how the lines are run the rest may or may not come out with time. If not the cylinder circuit will need to be bled too.

My second thought is something is clogging a fitting. Either a QD when you hooked it back up or a chunk of crud or sealant got into the circuit.

Tx Jim · Dec 5, 2019

Welcome to TBN
I agree cycling hyd cylinder(extending/retracting rod) should purge any trapped air. Having air in hyd system shouldn't affect engine full WOT rpm's. Please elaborate on the 40 second start up procedure.

dickhob · Dec 5, 2019

Tx Jim said:
Welcome to TBN
I agree cycling hyd cylinder(extending/retracting rod) should purge any trapped air. Having air in hyd system shouldn't affect engine full WOT rpm's. Please elaborate on the 40 second start up procedure.

From the SC2044 operator's manual-

6. Reinstall and tighten the transmission drain plug.
7. Clean the area around the oil fill cap, then remove the oil fill cap from the transmission housing.
8. ADD approximately 2.0 us gal (7.5L) of the transmission oil.
9. Reinstall the oil fill cap.10.Start the engine and idle it for about 40 seconds.
11.Run the engine at the high-idle speed for about 40 seconds.
12.Then, run the engine at the low-idle speed and slowly step on the forward and reverse drive pedal several times.
13.Again run the engine at the high-idle speed and slowly step on the forward and reverse drive pedal several times.
14.Stop the engine. If any leakage is found, contact your local Cub Cadet Yanmar dealer for technical assistance.
15.After leaving the engine for 5 minutes or more, check the transmission oil level and add more as necessary.

I did this procedure several (4) times.

It was while doing this that I noticed the low rpm. After sleeping on it I wonder if I have a clogged injector or water in the fuel. I religiously use 2oz/5gal of injector cleaner.

I've also cycled the FEL several times and will continue to do so after rechecking the hydro connections for junk.

DickHob