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Subject: 601 oil leakage from hydraulic sump to transmission

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Richard NY 2N    Posted 05-27-2018 at 16:18:44 [URL] [DELETE]        [Reply] [Email]  
  • 601 oil leakage from hydraulic sump to transmission
  • Is there a seal between these two sumps? My 711 loader wasn't lifting so I checked the trans level and found it low. After adding enough oil to get the loader working there was oil coming out around the shifter boot. What gives? Thanks for any help on this issue.

    Ultradog MN    Posted 05-27-2018 at 18:37:46 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 601 oil leakage from hydraulic sump to transmission
  • You're not going to like to hear this...
    There are two tubes that go through the bottom of the transmission case for the hydraulics on that tractor. They are known to rust through - after 60 years. What is happening is your pressure line has a hole in it and is essentially emptying the hyd reservoir and over filling the transmission and causing it to puke oil out of the shifter.
    There is a fix. I haven't done it myself. It requires inserting a new, smaller tube through the old one. I think? it requires a rear split to repair. There is likely some members here who can give you more info than I. If not I have seen numerous threads about it on the YT Ford board.
    I mostly just mess with the 3 banger Fords and on those the hyd lines are external or the pump is in the rear.

    Richard NY 2N    Posted 05-28-2018 at 15:42:56 [URL] [DELETE]        [Reply] [Email]  
  • Re: 601 oil leakage from hydraulic sump to transmission
  • Thank you. Could you post my issue on yt site? I can't log on, but I read the problems being discussed. Again, my thanks for your help.

    TheOldHokie    Posted 05-29-2018 at 05:13:27 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 601 oil leakage from hydraulic sump to transmission
  • New replacement pressure tubes for both four speed (NCA-945B) and five speed (NDA-945B) transmissions are available. Fairly simple repair - pull the old one out and drive the the new one in. Requires splitting the tractor. I have no experince with the aftermarket replacements but here is one source - 4th and 5th items on the page.


    Replacement Hydraulic Tubes

    Richard NY 2N    Posted 05-29-2018 at 06:41:07 [URL] [DELETE]        [Reply] [Email]  
  • Re: 601 oil leakage from hydraulic sump to transmission
  • Thanks for the source. I will have to get an order placed. Now to find a utube video of splitting the tractor for the fix.

    Ultradog MN    Posted 05-29-2018 at 07:56:35 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 601 oil leakage from hydraulic sump to transmission
  • Richard, Am pretty sure it is a rear split that you have to do. The front of the tube is accessible once you remove the hyd manifold.
    Rear split is pretty easy. Less work than an engine/trans split.
    I don't know why I keep thinking they pushed a smaller metric? tube through the original tube.
    Maybe hard to get the old one out? Cost?
    You might consider trying to pull the old one out before ordering.

    TheOldHokie    Posted 05-29-2018 at 08:38:15 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 601 oil leakage from hydraulic sump to transmission
  • This has been beat to death on the forums. From an old 2007 post:

    The tube came out with a marking of NCA 945 B. I dont know if that makes it an original or not. The specs John Smith gave me on the tube were off by a little and incomplete. I'll post mine for reference.

    The tube is .500 inch OD steel tubing 26 11/16ths inches (he said 26.5) in length. The wall of the tube appears to be slightly less than 1/16th thick, it would have to be to allow sleeving with a 10mm OD tube. I cant measure it accurately without hacking the tube but since 10mm is 0.393 im assuming the ID is .400 and therefore the wall thickness is .050. The front inch is .505, the next 14.5 inches are .500, 15.5 inches from the front the tube tapers to .495 for one inch, then down to .490 until 25 1/4 inches from the front it is turned down to .485 for the last 1 7/16ths inches.

    John's instructions are to turn the tube down to .485 all the way after the .495 section. He also didnt record the distance from the front to start turning the center section. Since the wall is only .050 thickness I plan to follow the tube in hand and keep as much steel as possible. My leak was right at 25 inches from the front.

    The tube goes through different diameter holes in the internal walls of the sump and has to be removed and installed from the front. If you are going to replace it probably easiest to tap threads in that end of the tube and use a puller to remove it. That may or may not require a transmission/engine split depending on what sort of obstructions you have to deal with. IIRC John Smith's site had a tutorial on the tube and its R&R.


    Ultradog MN    Posted 05-29-2018 at 09:12:08 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 601 oil leakage from hydraulic sump to transmission
  • Though not exactly beat to death, I did find a couple of refrences to NCA 495 B on YT using Google advanced search.
    One is the quote you found - from Jmor.
    Follow the link below.
    That thread also explains how to glue a 10mm tube inside the old one should someone wish to go that route instead.

    Ultradog MN    Posted 05-28-2018 at 17:34:56 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 601 oil leakage from hydraulic sump to transmission

  • Send an email to support@yesterdaystractors.com
    Give them your username and they will send your password to you.
    Then login and post on the Ford board - not the N board there.
    It's not that I won't help you but I do think you would get better results if you ask there yourself.
    I'm certain they can and will help. It is a very good board.
    Since you mention a shifter boot I assume your 601 is a 641?
    If so title your post - Oil pushing out of shifter boot on 641.
    I follow that board closely and will chime in if I can help in any way.

    Richard NY 2Nand    Posted 05-29-2018 at 20:14:32 [URL] [DELETE]        [Reply] [Email]  
  • Re: 601 oil leakage from hydraulic sump to transmission
  • You guys are great! I'm reading about the different ways to solve the problem. Probably replacing the tube is the way I will go. Many thanks to ulradog and old hokie for the information.

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