[kelley]

I'm trying to find the relief valve on an old 300 garden tractor. I'm hoping to adjust the hydraulic pressure up a little for quicker response on my pull-type rototiller. Thanks in advance 👍

 

[stevev]

I've got a 1975 300. Built a pin on loader for it. Wanted to boost the pressure a bit, so I shimmed the implement relief valve. Here's some pics.

 

[kelley]

Very cool. Looks like I'll take the seat pan off and see what I can see. Something's either wrong with this tractor or the brand new lift cylinder I bought is bogus. I can only get it to move a tiny bit after I start the engine, and then nothing. Plenty of oil and a new filter. Thanks for responding 👍

 

[kelley]

I've got a 1975 300. Built a pin on loader for it. Wanted to boost the pressure a bit, so I shimmed the implement relief valve. Here's some pics. View attachment 284393 View attachment 284395

I forgot to mention that I don't have any weight on this cylinder. Just trying to get it to move.

 

[TempletonJDguy]

Have you verified the set screw is tight on the woodruff key/shaft between the lever and the hydraulic spool linkages?

sometimes if it’s loose it feels like your moving the lever but it’s actually just rotating on the shaft

 

[stevev]

You could try plugging in a pressure guage to the front hyd outlets and see if you're building any pressure while working the levers.

 

[kelley]

Well fellas, I finally found the problem. The two ports I was using (formally went to the front) just wouldn't work, so I switched the whole mess to the other two ports, and everything worked like it should. I have no idea what was wrong, but I only need 1 system for the tiller, so for now I'm good. I can get the cornstalks turned under and be done for the fall. I have an old JD dozer I'll rig up for snow if I need it. A big thank you to everybody that responded 👍

 

[kelley]

Well fellas, I finally found the problem. The two ports I was using (formally went to the front) just wouldn't work, so I switched the whole mess to the other two ports, and everything worked like it should. I have no idea what was wrong, but I only need 1 system for the tiller, so for now I'm good. I can get the cornstalks turned under and be done for the fall. I have an old JD dozer I'll rig up for snow if I need it. A big thank you to everybody that responded 👍

 

[kelley]

You could try plugging in a pressure guage to the front hyd outlets and see if you're building any pressure while working the levers.

I'm going to do just that when I get the tilling done, so I can rig that cylinder up on a dozer. I'm guessing that part of the control valve needs rebuilt.