656 FYI

Anonymous-0 · May 6, 2014

Recently I posted about my 656 hydraulics. I thought I would share what I found was wrong. The 3 point would not raise without using aux. valve. Thought the unloading valve was sticking. Took it apart and replaced O-rings in the piston. Put it back together and still did the same thing. My last resort was to see if the unloading piston was still available from dealer. It was. I ordered it and put it in and it now works. Just thought I would let you all know the end result of my problem. You never know it could help someone someday. Thanks for anyone who contributed to my initial post.P.S. Hold on to your shorts when you find out the price of that little piston. 190.00,but it fixed my problem. That's all that matters. Doug

pete 23 · May 7, 2014

Good to hear you got the hydraulics working properly. I have a question. Was the orfice in the new piston same size as old one, was orfice in old one plugged, did you blow air through it. Also, did the spring loaded piston in old one and new one seem to have same compression pressure.

Anonymous-0 · May 7, 2014

The new piston and the old piston were the same size. I never did see an orifice in either piston. The old piston just seemed to have some drag on it. I replaced O-rings on old piston and even went as far as using a brake cylinder hone on the piston opening. I also used some real fine emery cloth to smooth up old piston. Still did not help. I put new piston and there was not any drag. An old mechanic buddy of mine said it should almost like there was no o-ring on it. and it does. As far as compression pressure,I believe they were the same. Hope this helps Doug

pete 23 · May 7, 2014

Not trying to pester you here, but the orfice should be quite easy to see. It is a very small hole down inside of a little larger hole and leads to the inside of the piston and out the other side.. This allows fluid to escape from one side of piston too the other side other wise hydraulic lock occurs and the piston cannot move. Normally when a hitch gives this problem the orfice has a tiny bit of junk plugging it. As far as the spring, I mean the one that is inside the piston. It is a crimped assembly so it cannot be taken apart but some times that spring breaks and if you push down on the pin end of the piston you can tell a difference from a new piston. I have not seen that happen on a 656 but was not uncommon on older tractors.

Anonymous-0 · May 9, 2014

Pete

I will look at the old piston when I get a chance. Did not know that there was a spring in the piston. There were 2 small holes in the piston, but did not look like they were anything special. Will have to look a little closer this weekend

Doug

656 FYI

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