3-Point Hitch Iseki 1300 hydraulic system pressure relief

[eccchief]

Okay, so I'm tilling a fire break along the edge of my place and 'pow' the hydraulic pump housing busts, oil runs out on the ground, and I can't pick up the loader or tiller. I get the implements dropped and the tractor in the shop, find a replacement pump, and am ready to put it on. But wait...why did it bust in the first place? Well, hmmmm, there must be a pressure relief valve here somewhere that is stuck closed. A hydraulic pump is positive displacement, so when the valve for the rear lift is closed, something has to let that pressure through to the return line or else the weakest point is going to break(turned out to be the aluminum pump housing). So I remove the control valve(right side of seat mounted on transmission case) and tear it apart. Then I pull out the set of manuals I bought from Hoyt tractor in Texas, you know, the parts catalog that is all in Japanese, and an English version service manual that has all the parts manuals same exploded views copied into it, some photo-copied pictures that are unreadable, and no details about the hydraulic system or how presssure relief is handled. No help!
SO...my next question is...
Are any of you guys out there familiar enough with the hydraulic system to guide me to the pressure relief function? I really don't want to put on this $500 pump and have it split open the minute I fire up the tactor.

I am anxiously awaiting the wisdom that I know is out there......somewhere.

 

[BillS2009]

Not familiar with your model, but the pressure relief valve should be in the oil reservoir. On my TS-1610 it appears to be built in with the slow return check valve. That is the adjustment that slows the drop of the three point hitch. Mine is located to the drivers right under the seat.

 

[J_J]

Just curious about the relief valve you think caused the problem. Were you using any valve levers before the hyd quit? If you were not using any valves, the relief valve would not be working under any pressure. The fluid would just be flowing from pump to tank.

If you did have the 3pt lever in the max up position, the relief would go off, but the tiller or whatever would be in the fully raised position. You might not have heard it, and it might have been activated for a wile. It would surely have heated up the fluid.

If you can find the relief valve, remove, inspect and clean.

Is that 3pt relief valve the only relief valve in your system.

If you are not sure about the 3pt relief valve, you could add an external relief valve before the 3pt valve as a safety. You would need to run the relief OUT port to tank.

Your 3pt relief valve might be under a hex plug, or a plate at the back.

 

[suntreemcanic]

If your pump split, look for any sigh of metallic in the oil, any contamination has to be removed (cleaned up). You will have to drain the gear case and flush it out or the metal fillings will eat up the next pump. Your gear case is the reservoir for the hyd. oil.