Port Drive does not go down??
10-28-2012, 03:19 PM
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Port Drive does not go down??
Hi..The port drive on my cig does not go down any more..it is all the way up..and now seems stuck..is it possible for the drive to
have a "point of no return", that someone get's it up so high that it can get damaged?? Thank's for the feedback!!
have a "point of no return", that someone get's it up so high that it can get damaged?? Thank's for the feedback!!
10-28-2012, 05:03 PM
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10-28-2012, 05:06 PM
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sometimes they get pressure locked meaning when you ran it up all the way it built up so much pressure and when you hit the down switch it binds in the pump..first have someone operate the switch in the down position and you will need to jump up and down on the captivation plate,,this may jar it loose...if that dpnt work try loosening the steel lines at the trim cylinders and push down on the drive again..
10-29-2012, 06:34 AM
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it isn't the drive, it is the trim cylinders. the tilt mech uses a lot more pressure to raise drives, cuz they hafta stay UP against 260 to 600 HP trying to push them down. down takes very little pressure cuz the motors are usually helping drive go down. if (when) a seal in the middle of trim cyl lets go, the down pressure goes thru and fills the up side, which has a lot more-we'll call it leverage. so down pressure is actually raising the drive. first, check fluid level in pump and run up and down. do you hear pump practically stop when it hits the up stop? then pump is doing what it is supposed to. then take pin out attaching cyls to drive. run pump. the one that doesn't go down is the bad one. and i can't stress this enough. the moisture in fluid will cause a sticky spot on the cyl shaft. if left up all winter, they will be stuck there. leave drives down all week when on trailer, and especially all winter...
Last edited by dereknkathy; 10-29-2012 at 06:38 AM.
10-29-2012, 11:43 PM
#7
It's most likely o-rings in the trim piston, but also the trim pump has relief valves that control the up and down pressures. The "up" is set to 2500-4000 psi, depending on model, and down is like 250-400, again depending on model. So, the down really has very little authority, like liiterally if you are only putting 250 psi on one of those rams, minus the tailrod area, might only be a few hundred pounds per ram.
Some possible things that can happen in the pump:
1) The spring on the relief ball might have fatigued or broken. No spring pressure=no fluid pressure.
2) A piece of debris could have gotten lodged in the relief ball seat, holding it open
3) The pump is out of fluid (below the pickup) If your problem is coming at maximum "UP" this is highly likely, because this is the position at which the reservoir volume will be the lowest (again due to the tailrod volume in the pistons). The way I always fill mine is put the drives all the way down, and top off the reservoirs. That always means you'll have enough fluid, without overflowing.
Some indications: If your oil is foaming at the reservoir after running the pump for a bit, it is probably the relief valve shot. If the motor sounds like it's not "grabbing" anything, your fluid is low.
One thing you can try easily, is swap the hydraulic lines to a different trim or drive pump, and give it a go. That will allow you to see quickly if your problems are with the pump or the rams. If you have a problem in a ram, you really can't tell which ram unless you make up a custom single ram hose set, or test it with other means.
I battled one side of my SSM's for a long time before I figured out that I had both a bad pump, and a bad ram. Very frustrating.
Some possible things that can happen in the pump:
1) The spring on the relief ball might have fatigued or broken. No spring pressure=no fluid pressure.
2) A piece of debris could have gotten lodged in the relief ball seat, holding it open
3) The pump is out of fluid (below the pickup) If your problem is coming at maximum "UP" this is highly likely, because this is the position at which the reservoir volume will be the lowest (again due to the tailrod volume in the pistons). The way I always fill mine is put the drives all the way down, and top off the reservoirs. That always means you'll have enough fluid, without overflowing.
Some indications: If your oil is foaming at the reservoir after running the pump for a bit, it is probably the relief valve shot. If the motor sounds like it's not "grabbing" anything, your fluid is low.
One thing you can try easily, is swap the hydraulic lines to a different trim or drive pump, and give it a go. That will allow you to see quickly if your problems are with the pump or the rams. If you have a problem in a ram, you really can't tell which ram unless you make up a custom single ram hose set, or test it with other means.
I battled one side of my SSM's for a long time before I figured out that I had both a bad pump, and a bad ram. Very frustrating.
10-30-2012, 05:16 AM
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sometimes they get pressure locked meaning when you ran it up all the way it built up so much pressure and when you hit the down switch it binds in the pump..first have someone operate the switch in the down position and you will need to jump up and down on the captivation plate,,this may jar it loose...if that dpnt work try loosening the steel lines at the trim cylinders and push down on the drive again..
10-30-2012, 06:32 PM
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Thank's guys tried the bouncing on the drives already..no result there took of the cylinders now, opend them up replacing the seals, as they did not move at all even when removed and no pressure on them, if that doesn't help that it must be the pump..i guess.
