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Subject: Mairose

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Dave    Posted 01-06-2021 at 23:37:26 [URL] [DELETE]        [Reply] [Email]  
  • Mairose
  • I have a 9n with a due all loader. It has a gresen 12 gallon a minute pump. The spool squeals like crazy and almost kills the engine when going down Had the cylinders and spool gone through. Next step is to put a different ring in the pump to cut it down to 3 gallons a minute. I think it would be to slow. Backed off the pressure valve on the spool so it almost works like it should. Any input?

    TheOldHokie    Posted 01-07-2021 at 01:45:48 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Mairose
  • I think your problem is likely incorrect plumbing. Sounds like a double acting spool on the valve is being used to control a single acting lift cylinder and the unused port on that spool has been plugged. Common mistake. Remove the plug and connect that port to the tank return and your squeal and load will go away.

    TOH

    Dave    Posted 01-07-2021 at 10:09:41 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Mairose
  • The cylinders are 2 way and all of the ports on the spool have plumbing. The weird part is it only squeals on the way down

    mhb@ufe    Posted 01-07-2021 at 10:44:32 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Mairose
  • Some valves had a restrictor in the lowering port so the loader wouldn't drop fast. If you raise the loader and shut the tractor off does it still squeal going down or go down slow? Some valves also where made without a relief machined on the spool so that if you don't move the valve full stroke they can actually build excessive pressure.

    Mark

    carl nny    Posted 01-07-2021 at 11:05:51 [URL] [DELETE]        [Reply] [Email]  
  • Re: Mairose
  • This may sound stupid, but you don't have a line criss-crossed do you ?? Just a thought..

    TheOldHokie    Posted 01-07-2021 at 11:39:26 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Mairose
  • Not crazy in the slightest. Something is almost surely deadheading the bucket "lower" circuit. If the cylinders are DA crossing the plumbing on the lift cylinders would produce something like these symptoms. I would inspect that plumbing and try removing one or more hoses or eliminating one cylinder to identify the location of the obstruction.

    TOH

    carl nny    Posted 01-07-2021 at 15:46:42 [URL] [DELETE]        [Reply] [Email]  
  • Re: Mairose
  • I wasn't sure.. I'm not the greatest on hydraulics, I can run the lines ok but not really up on the controls and what causes what.. It just happened to cross my mind that "maybe"......LOL

    Dave    Posted 01-08-2021 at 10:19:39 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Mairose
  • Pulled off all up a d down hoses from the cylinders a d spool.inside of hoses and fittings were good. Blee air through the pipes no obstructions.problem must be in the spool. Dont have the slightest idea of how all that is supposed to go

    TheOldHokie    Posted 01-08-2021 at 10:43:17 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Mairose
  • Isolating this is not hard. Hook it up to just ONE of the cylinders (unloaded) and cycle it. Tell me what you get. If it does not work properly hook it up to the other cylinder, cycle it, and tell me if it is any different. Also post a couple pictures of the valve showing ALL connections.

    TOH

    TheOldHokie    Posted 01-08-2021 at 12:27:51 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Mairose
  • I should have added start by cycling the valve without any cylinders connect. Put the ends of the two hoses in a bucket to catch the oil. If you have a problem in that case the problem is somewhere inside the valve. If that works OK the problem is in the cylinders and/or plumbing.

    TOH

    Dave    Posted 01-08-2021 at 21:48:22 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Mairose
  • Ok will try that may take me a couple of days as I work alot.will let you know what happens.

    TheOldHokie    Posted 01-09-2021 at 05:41:58 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Mairose
  • Dont forget to post some pictures of that valve. Has this setup ever worked properly?

    TOH

    Dave    Posted 01-12-2021 at 20:55:49 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Mairose
  • Took some pics but my phone wont let me post them.turned the pressure valve in a ways.put a pressure gauge on the pressure side. Tested the spool with 2 hoses in the pail worked fine to me.tested the left cylinder by unlocking it on the bottem side and running it up a d down. 100 lbs of pressure going up and 500 lbs pressure going down. Right cylinder 100 lbs going up a d 800 lbs going down.not thi king it's the packing because wouldnt it do it up also.these were rebuilt 2 years ago by a reputable hydraulic shop.the loader works much better back g the pressure valve way off

    TheOldHokie    Posted 01-13-2021 at 06:30:07 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Mairose
  • I forgot - set the relief back up to 1600 PSI before conducting any more pressure tests.

    TOH

    TheOldHokie    Posted 01-13-2021 at 06:23:03 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Mairose
  • Email your pictures to me and I will post them for you.

    Reducing the relief pressure is just masking the problem and reducing the lifting capacity of the loader.

    The 500 and 800 PSI pressures are too high for an unloaded cylinder. Something in that circuit is not right.

    Disconnect the hoses and repeat the bucket test. This time record the inlet pressure and tell us what you get in both spool positions.

    If you go step by step you will find the problem.

    TOH

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