Ford 600 hydraulic issues cont part 3

I want to start out saying thank you for all the useful information here on the site. Everyone as really helped me with this job and feel silly that I took lid off, put back on and not working right still. Sounds like I may have to take it off again.

[b:23445d94e5]Work Done[/b:23445d94e5]
I started out having a weak lift and wouldn't go up all the way. It would get implement off ground, but didn't lift to full potential. So, I pulled off the lid, changed piston, o-rings and cam follower pin (really worn). I didn't get in the valves as did not have the tool/puller to pull them out.

[b:23445d94e5]Problem[/b:23445d94e5]
Put everything back together last night. Started the tractor and let it run for a few min. Engaged the touch control lift and nothing happened... then 20 seconds its started lifting. It lifted all the way up and I was like YES!!!!!

However, once got all the way up, it started hiccuping. Would bounce down a 1/4 inch and then go back up... this continued only on the lift not on the lower. I didn't get to mess with it too much more, as was late. Nor sure this would do this with implement or hold and implement. What would cause this? Could this be me putting the piston o ring on incorrectly? Air in the system? It wasn't doing this before.

I had a similar problem with my 600 about 25 years ago.
I discovered that when I loosened the plug on the hydraulic
pump it blue out a little air. It would work fine for a couple
days then had to bleed again. I bought a rebuild kit for the pump,
which had a hat full of little parts in it, and had a mechanic friend
rebuild it.
While I was at it I took the top lid to a Ford tractor dealer and had
him replace anything that looked like it need replacing.
Haven't had one problem since.

Sounds like you are making good progress. Congratulations.

Hiccuping is a common problem. A search of the archive will turn up lots of post. The short answer is you have a small leak between the control valve and the piston/cylinder. The hard part is finding it. If you lift a weight with the 3-point, hold up the load and turn the tractor off and then look in the fill hole or remove the round PTO lever cover and look inside with a small flash light (and maybe a mirror) you might be able to see a small drip. Lots of possibilities. Mine was a worn control valve.

What happens is the small leak allows the load to drop a bit. The control circuits detect it and lift the load. Then it repeats over and over. Result is called hiccuping.

(quoted from post at 01:55:17 02/21/18) I had a similar problem with my 600 about 25 years ago.
I discovered that when I loosened the plug on the hydraulic
pump it blue out a little air. It would work fine for a couple
days then had to bleed again. I bought a rebuild kit for the pump,
which had a hat full of little parts in it, and had a mechanic friend
rebuild it.
While I was at it I took the top lid to a Ford tractor dealer and had
him replace anything that looked like it need replacing.
Haven't had one problem since.

Click to expand...

I had the same problem with my 600 as rdobbs stated my live does hiccup but about once a year it will not lift when I crank it. So I take the pipe plug out of the top of the hydraulic pump turn the motor over remove the air put the plug back in and it works fine for another year. You may want to try that I'm sure there is air in the system or pump