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cmcgalla 07-27-2012 17:59:26 50.41.135.76 Report to Moderator	I just bought a 1956 Minneapolis Moline 445 Industrial, witch a Shawnee Warrior loader and hoe. The hoe seems a bit weak and I know very little about hydraulics. The good folks at the n-board have been a great help so far. I wanted to post here since my question is more general and maybe beneficial for some. I was told I could test the cylinder by disconnecting a line, capping that line and working the stick. If there is a problem in the cylinder I was told that hyd. oil would squirt out the open port, thus proving something was bad. I can't remember if he said to do this test with the rod all the way out or all the way in? Does anybody know what he is talking about? He knew his stuff, I just didn't take notes . . . Thanks Zeek [Reply]   [No Email]
Frank A 07-29-2012 05:53:36 206.246.4.50 Report to Moderator	Re: Hydraulic Test in reply to cmcgalla, 07-27-2012 17:59:26   The cylinder would need to be bottomed out against the side you take loose. If the cylinder moves any at all the oil that is in that side will come out. Make sure everthing is braced so nothing can fall on you. I"m not sure this is a very good test because most damage to the cylinder would be more in its normal travel area. Good luck Frank   [Reply]  [No Email]
Jesse in Wi 07-28-2012 18:17:32 74.33.118.181 Report to Moderator	Re: Hydraulic Test in reply to cmcgalla, 07-27-2012 17:59:26   Is it making required pressure? Sometimes a piece of grit will get into the relief vakve, blocking it open. Or you could have a worn pump, unable to make sufficient pressure. Best way to test is with a pressure guage. Leaking piston seals inside the cylinder may have an effect. I would image that winding the engine way up would have a direct effect in making pressurealong with speeding up hydraulic action.   [Reply]  [No Email]
cmcgalla 07-28-2012 18:31:41 50.41.135.76 Report to Moderator	Re: Hydraulic Test in reply to Jesse in Wi, 07-28-2012 18:17:32   I don't know if it is making the required pressure, I have to test. I just bought a 5000 PSI gauge, but it has what looks like 3/4" brass, male threads, its a typical hydraulic gauge, but how do I interface it with my pump? I assume there is a test port on the pump that will accept the gauge, I just have to find it. What if I want to test the valve/spool, how do I connect the gauge to the hose? I know these are basic questions, so bear with me. Thanks Zeek   [Reply]  [No Email]
Jesse in Wi 07-29-2012 17:28:50 74.33.118.181 Report to Moderator	Re: Hydraulic Test in reply to cmcgalla, 07-28-2012 18:31:41   When I tested mine I used a tee fitting. The gage was sticking out the top (tee was upside-down). I disconnected a hose from the valve bank. I connected one end of my gage-tee-contraption to the valve bank. I connected the hose back onto the open end of the tee. In essence I got the gage-tee in-line with a pressure hose to a cylinder. (Does't really matter what hose. It would probably work best on the hose that pulls the lower boom toward you ["crowd in" I think its called]). Now when you actuate the cylinder you will have a direct pressure reading on that circuit. The system wont generate max pressure unless you try to make it do more than it can... ie, against the stop and keep going. Or get the hoe up against a stump it cant move. When the pressure stops rising, drops a bit (opposite of a pressure spike) and steadies, that means your relief valve is open.   [Reply]  [No Email]
cmcgalla 07-29-2012 18:46:23 50.41.135.76 Report to Moderator	Re: Hydraulic Test in reply to Jesse in Wi, 07-29-2012 17:28:50   Great thanks makes sense. I have to run to the store tomorrow to get the right fittings and then will post the results. Zeek   [Reply]  [No Email]
NCWayne 07-27-2012 23:02:25 69.40.232.132 Report to Moderator	Re: Hydraulic Test in reply to cmcgalla, 07-27-2012 17:59:26   Depends on which way you think the seals in the cylinder are leaking by. If you suspect them leaking by in the down position, draw the cylinder all the way in and crack the hose from the bottom fitting. With the line cracked operate the lever to boom down. If the seals are leaking for boom down (from the top to the bottom of the cylinder), oil will squirt out of that fitting. If you suspect they are leaking in the boom up position, raise and support the boom on something to insure it does not fall, an dinsure the cylinder rod is extended all the way out. Once the boom is supported, crack the line on the top side of the cylinder and operate the lever to boom up. If oil squirts from the upper line then the seals are leaking past from the bottom to the top of the cylinder. Without knowing exactly what seals are in the cylinder that is the only real way to test it. I say that because some cylinders have only one seal that works both ways while others will have a individual seal for each direction. Good luck.   [Reply]  [No Email]
cmcgalla 07-29-2012 04:58:11 50.41.135.76 Report to Moderator	Re: Hydraulic Test in reply to NCWayne, 07-27-2012 23:02:25   NCWayne, I'm confused after re-reading your post. If the rod is all the way out, fully extended how will cracking the top line help? I might be wrong here, but doesn't the top line (by top line I mean the one closest to where the rod comes out of the cylinder)push the rod back in to the cylinder? Maybe I am not understanding what goes on in a cylinder. I thought that in order to test the seals to see if oil is pushing past them I would put the rod all the way out, crack bottom line, work lever to retract. Then the hyd. oil would push against the rod (inside the cylinder)and if it was all good no pressurized squirt of oil would come out of the bottom, partially opened line, but if the seals were bad, hyd. oil would squirt past the seals and out the bottom line. Is that making sense at all? Thanks for being patient with me Zeek   [Reply]  [No Email]
Dave in Tx 07-28-2012 14:42:54 166.147.72.29 Report to Moderator	Re: Hydraulic Test in reply to NCWayne, 07-27-2012 23:02:25   cylinders with holding valves on them will have stand-by pressure on both sides. You have to cap the line to keep it from pouring oil out of it.   [Reply]  [No Email]
cmcgalla 07-28-2012 03:19:08 50.41.135.76 Report to Moderator	Re: Hydraulic Test in reply to NCWayne, 07-27-2012 23:02:25   Thanks Wayne. Are you saying I don't have to totally disconnect the line and cap it? If there is a leak inside the cylinder the fluid will squirt out of the partially open line, correct? Zeek   [Reply]  [No Email]
NCWayne 07-28-2012 21:04:47 69.40.232.132 Report to Moderator	Re: Hydraulic Test in reply to cmcgalla, 07-28-2012 03:19:08   On a machine that old you ought to be able to just crack the line without having to pull the line and cap it. Another post mentioned a holding valve, and if it had a holding/lock valve then the line would need to be capped, but I've never seen a machine that old with a holding/lock valve. That said cracking the line should work but if you've got caps for the lines then it won't hurt to completely remove the line and cap it either. Granted by just cracking the line instead of removing and capping it you might see a small amount of flow from the line, dependent upon the way the system is designed, when the machine is running, but when the other end of the cylinder/piston is pressurized the high pressure/additional volume will be apparent enough to see, and at least it won't be squirting out a wide open fitting.   [Reply]  [No Email]