Author	[Modern View]
Matt Wedig 09-03-2012 13:17:07 107.8.195.196 Report to Moderator	I am looking for some advise, the rockshaft housing cracked up by one of the remotes from a pressure spike. I was driving the tractor when it happened, it seems that the three point hitch arms started rasing on their own and dead headed the hyd system until something let loose. I have a used houseing I am installing. What should I look for to make sure this does not happen agian ? Thanks [Reply]   [No Email]
Ken11487 09-04-2012 19:20:49 64.66.236.36 Report to Moderator	Re: 1969 4520 Hyd issue in reply to Matt Wedig, 09-03-2012 13:17:07   When I got parts to rebuild the rockshaft control valve on my 4320 the senior mechanic told me that there would be enough leakage on a used tractor to equal what the thermal relief valve does and the valves purpose was mostly for when the tractor was new. A rebuild of the control valve on my tractor made quite a difference in noise and handling of the three point hitch. What was the three point hitched to when it broke? Was it very heavy? Was then load bouncing? [Reply]  [No Email]
Cliff Nelson 09-03-2012 20:24:44 96.60.120.179 Report to Moderator	Re: 1969 4520 Hyd issue in reply to Matt Wedig, 09-03-2012 13:17:07   The three point is dead headed when fully raised anyway so that did not cause your problem. Check standby pressure which should be 2250 psi. Is it cracked from the pressure port or the return port? [Reply]  [No Email]
Matt Wedig 09-04-2012 04:42:19 107.8.195.196 Report to Moderator	Re: 1969 4520 Hyd issue in reply to Cliff Nelson, 09-03-2012 20:24:44   It cracked at the end of the housing near the piston for the 3 point arms. See pic Thanks [Reply]  [No Email]
Cliff Nelson 09-04-2012 05:35:04 96.60.120.179 Report to Moderator	Re: 1969 4520 Hyd issue in reply to Matt Wedig, 09-04-2012 04:42:19   Take the rockshaft valve to a dealer and have them test the thermal relief valve. If the rockshaft was fully raised and not being used a stuck thermal relief valve would allow high pressure to build up due to thermal expansion. Check standby pressure also but the pressure to split the housing should have caused other problems if caused by standby pressure. [Reply]  [No Email]
MSM 09-03-2012 14:54:57 75.197.140.146 Report to Moderator	Re: 1969 4520 Hyd issue in reply to Matt Wedig, 09-03-2012 13:17:07   You sure the lift arm didn't hit the tire and throw it up hard enough to crack the housing?If you had that much pressure, you would have other hydraulic issues. Check the standby pressure, it should be 2250 lbs [Reply]  [No Email]