N Board Forum - Expanded Thread Page

Subject: 53 three point wont lift

[Back] [Return to Top of Forum]

Doug    Posted 06-12-2018 at 07:01:02 [URL] [DELETE]        [Reply] [Email]  
  • 53 three point wont lift

  • my three point on my 53 will not work. over the winter we replaced hubs and axle seals, while it was apart we replaced the piston and relief valve because the lift would drop with any type of weight on it. put everything back together and the lift worked for a couple days then just stopped. i put a hose on the high pressure pipe fitting lower right side and ran a hose back into the center section, pump volume was low. so rebuild the piston pump (after waiting three weeks for the valve removal tool). pump volume is better not sure its 4 gallons a minute but its better. still nothing. we cleaned the center section, cleaned out the manifold if we remove the side cover and look into the center housing there is no visible oil coming from the piston or the relief valve. any help is appreciated, thank you.

    JMOR    Posted 06-12-2018 at 07:44:39 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 53 three point wont lift
  • Are you sure the back pressure valve and seal between it an cylinder assy is in place and secured by the acorn nut assembly on right side of housing?

    Doug    Posted 06-12-2018 at 08:37:37 [URL] [DELETE]        [Reply] [Email]  
  • Re: 53 three point wont lift
  • i believe it is, but i will check that after work.

    JMOR    Posted 06-12-2018 at 08:46:35 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 53 three point wont lift
  • If that is not the problem, then I would expect a stuck unloader valve. Note that without back pressure, the unloader valve will not work.

    Doug    Posted 06-12-2018 at 09:03:11 [URL] [DELETE]        [Reply] [Email]  
  • Re: 53 three point wont lift
  • where is the unloader valve? is that the relief valve?i was going to try and put the old one back in and see if that changed anything.

    Rich    Posted 06-13-2018 at 11:18:54 [URL] [DELETE]        [Reply] [Email]  
  • Re: 53 three point wont lift
  • Hi I've been working with Doug on the lift arm. You show a pic of a unloading valve. what I've seen that is the new style and Doug has the old style. Not sure if that makes a difference. Also on the back pressure valve (the one with the acorn nut)how do you tell if you have flow. That tube goes strait down into the return port am i missing something. On the pressure side of the system there is a relief valve how come we don't see any fluid from that.

    Rich

    JMOR    Posted 06-12-2018 at 09:19:17 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 53 three point wont lift
  • Deep inside the lift cylinder casting.

    Doug    Posted 06-13-2018 at 06:55:12 [URL] [DELETE]        [Reply] [Email]  
  • Re: 53 three point wont lift
  • we pulled the side cover off, left side. there is no movement in the oil what so ever, we rebuilt the pump an i have more flow then i did previously. i am going to put a pressure gauge on the lower right side and see what i get. i was told it should be 2000 psi? that sound correct?

    JMOR    Posted 06-13-2018 at 07:35:28 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 53 three point wont lift
  • ~2000, but if unloader valve is dumping & not directing flow to lift cylinder, then pressure will not be anywhere near 2000. If working properly, then pressure would be proportional to the weight of load being lifted. In other words, unless you do something to block the pump output flow, the pressure measurement will be relatively meaningless. Think of your garden hose with a nozzle on the end. Shut off, the hose pressure is the supply pressure, but remove the nozzle, now at full flow, the pressure is near zero.
    You mention no movement of oil in sump. Did you look or feel for flow out of backpressure valve tube?

    Doug    Posted 06-13-2018 at 08:34:05 [URL] [DELETE]        [Reply] [Email]  
  • Re: 53 three point wont lift
  • the back pressure valve tube is what is behind the large acorn nut that runs down to the return line of the manifold? sorry i am not familiar with all the parts in the system.

    JMOR    Posted 06-13-2018 at 08:39:34 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 53 three point wont lift
  • yes

    Doug    Posted 06-13-2018 at 12:15:18 [URL] [DELETE]        [Reply] [Email]  
  • Re: 53 three point wont lift
  • Hi I've been working with Doug on the lift arm. You show a pic of a unloading valve. what I've seen that is the new style and Doug has the old style. Not sure if that makes a difference. Also on the back pressure valve (the one with the acorn nut)how do you tell if you have flow. That tube goes strait down into the return port am i missing something. On the pressure side of the system there is a relief valve how come we don't see any fluid from that.

    Rich

    JMOR    Posted 06-13-2018 at 12:58:22 [URL] [DELETE]        [Reply] [Email]  
  • Re: 53 three point wont lift
  • Old vs new unloading valve would be metal "o" ring vs 'rubber' I believe and operation would not differ. Back pressure line should not go directly into the return port, although I have heard of some that do (always assumed someone bent/installed it wrong). All I have ever seen dump out well toward rear of hydraulic compartment. Over pressure relief valve (near vertical pressure tube at right front of hyd compartment)will only open if hyd flo is blocked. If lift is working, this may be accomplished by chaining the lift arms down and giving a lift command. If lift not working that "chaining" will not work for measurement purposes. Flow can be blocked by plugging the accessory plate as in the attached (effectively blocking flow at top of vertical tube ...circled). If you wish to talk, send me an e-mail with a phone number.

    Doug    Posted 06-15-2018 at 06:24:22 [URL] [DELETE]        [Reply] [Email]  
  • Re: 53 three point wont lift
  • ok so my dad and i tried to prime the pump by adding air to the chamber, no luck. we tried bleeding air from the pump be loosening the pipe plug on the pump. i went a little too far with the plug and out it came. needless to say the pump is working, my dad and i got soaked. we are going to pull the top plate this weekend. i know the back pressure line in mine goes directly into the return, that is the way it was when we took it apart. we will change that, i have a different cylinder we may try and see if that is the problem. it just seems that no oil is getting to the control.

    JMOR    Posted 06-15-2018 at 08:32:29 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 53 three point wont lift
  • I don't know whether or not you have these flow diagrams, but they should help if you don't have them.



    Doug    Posted 06-16-2018 at 20:58:04 [URL] [DELETE]        [Reply] [Email]  
  • Re: 53 three point wont lift
  • So my dad did a little investigating and ended up a nearest tractor dealer near us. He spoke to the service manager who was very helpful and determined the pump is unable to prime. Turns out I forgot to put the o ring in the casing for the pump tube to the control. We had never pulled the manifold off of the top plate. We did the today so now I have to get new o rings for there. Are the specific in any way? I have some from the lift cover repair kit but the don't seem to fit that well. And there isn't one a similar size to the one that goes in the casing under the lift plate.

    JMOR    Posted 06-17-2018 at 08:01:05 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 53 three point wont lift
  • Take the old rings to auto supply and ask for new ones that match in size.

    JMOR    Posted 06-17-2018 at 14:04:19 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 53 three point wont lift
  • I'm at a loss on where you are talking about here" the casing for the pump tube to the control"? , Just curious. Thanks.

    Doug    Posted 06-18-2018 at 06:44:13 [URL] [DELETE]        [Reply] [Email]  
  • Re: 53 three point wont lift
  • i will get a picture later and email it to you, i have zero luck posting pictures on here.

    JMOR    Posted 06-18-2018 at 08:35:59 [URL] [DELETE]        [Reply] [Email]  
  • Re: 53 three point wont lift
  • OK

    Doug    Posted 06-12-2018 at 11:00:46 [URL] [DELETE]        [Reply] [Email]  
  • Re: 53 three point wont lift
  • of coarse, we will check that also. i have the parts book and shop manual but is there a little more detailed illustration of the control, lift cylinder. not sure what the correct mane is.

    [Back] [Return to Top of Forum]


    Top