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haymaker421 11-13-2009 13:26:49 75.100.135.224 737771 Report to Moderator	Getting ready to replace/repair the hydraulic pump on my 3388 for the third time. Why don't these pumps last longer? I have had IH tractors all my life and the only other hydraulic pump I ever replaced was on an 806 and that was 30 years ago. And man are they expensive! Anyone know where I can get one in good shape that doesn't cost an arm and a leg? [Reply]   [No Email]
pete 23 11-15-2009 21:22:02 173.87.147.73 738125 Report to Moderator	Re: 3388 Hydraulic pump in reply to haymaker421, 11-13-2009 13:26:49   On the filters again, the 2+2 used two small filters because the steering pump took it's oil through the end cover so due to this configeration the one large filter would not work as you needed the screen cold oil bypass in between. If you broke the shaft I am almost positive you have a worn out pto shaft and gear also. I have had to replace them.   [Reply]   [No Email]
pacer54 11-13-2009 18:51:54 207.161.206.64 737830 Report to Moderator	Re: 3388 Hydraulic pump in reply to haymaker421, 11-13-2009 13:26:49   A company Allied Precision, makes a filter extension which allows two filters to be used with these and other model tractors.Does anyone think that the increased flow of filtered hydraulic fluid might let the piston pump live a little longer?Just wondering.   [Reply]   [Send Email]
pete 23 11-14-2009 10:49:45 173.87.147.73 737902 Report to Moderator	Re: 3388 Hydraulic pump in reply to pacer54, 11-13-2009 18:51:54   I think the extra filter capacity would be a great idea and should help pump life. That being said, there are a lot of different types of pump failure on these series including the wearing out of the pto shaft spline and gear that drive the pump. Lots of time compensator was the problem, sticky spool. Polished several that would stick when warmed up, cool down and worked ok again. Plugged orfices or blown o-rings. The swash plate actuating piston would also stick in no flow positon. Found a couple of them. If you take the pump apart and the ball sockets are worn on the slipper pivots it is definetly cavitation causing it.   [Reply]   [No Email]
pete 23 11-13-2009 16:56:04 173.87.147.73 737804 Report to Moderator	Re: 3388 Hydraulic pump in reply to haymaker421, 11-13-2009 13:26:49   I think you will find the kit referred to will cost less than a new piston pump. Cavitation is indeed the main problem with that system. Piston pumps do not draw oil well, they need to be charged constantly. You will still use the same closed center valves and be able to control the volume of flow to outlets. Engineering did a quite a unique conversion on this system, using a unloading valve spool in place of the priority spool and it works out quite well.   [Reply]   [No Email]
dwag 11-13-2009 15:24:05 173.15.100.177 737788 Report to Moderator	Re: 3388 Hydraulic pump in reply to haymaker421, 11-13-2009 13:26:49   www.hy-capacity. They offer a kit to convert back to the gear pump. I believe a piston pump needs to be fed by a charge pump, which IH didn't use at the time, which caused cavitation. imho   [Reply]   [No Email]
bc 11-13-2009 15:08:41 69.148.145.104 737787 Report to Moderator	Re: 3388 Hydraulic pump in reply to haymaker421, 11-13-2009 13:26:49   What's wrong with them when you take them apart? I suspect a problem with the filter and screen and maybe some sludge trapped in the system somewhere.   [Reply]   [No Email]
haymaker421 11-15-2009 03:44:53 75.100.135.224 737979 Report to Moderator	Re: 3388 Hydraulic pump in reply to bc, 11-13-2009 15:08:41   Well first about the filter. The 2+2's had double filters anyway on the right side where the other 66's just had one. The first time the pump went out, the splined shaft broke and the same thing happened the second time but this time, though I haven't been able to get under the tractor to remove the pump, it seems that the whole housing has come lose some way or other. The transmission oil has all leaked out through the housing where it bolts to the rear frame.   [Reply]   [No Email]