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Subject: Leaking hydraulic pump assembly drain plug bolt

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Travis Webb (UT)    Posted 04-04-2020 at 19:18:59 [URL] [DELETE]        [Reply] [Email]  
  • Leaking hydraulic pump assembly drain plug bolt
  • When my 8N is running, I have hydraulic fluid that is pouring and running out of the plug bolt of the pump assembly, as if the bolt isn't even there. I've tightened the bolt, but that didn't help. Any ideas what would cause that, and how to fix it?

    Charles    Posted 04-04-2020 at 21:16:56 [URL] [DELETE]        [Reply] [Email]  
  • Re: Leaking hydraulic pump assembly drain plug bolt
  • What are you refering to as "The drain plug bolt of the pump assembly"? Do you mean the test port plug on the side, or the big drain plug at bottom of transmission.
    If its the test port leaking, do you have the right pipe plug thread (tapered thread on a pipe plug?
    BTW I have seen many tractors get moisture in the oil, thru many ways, if parked outside. Big spring of draft, shift boot. .Water in oil adds to depth and milkie colored oil. If so a complete drain and new oil is recommended.

    TheOldHokie    Posted 04-04-2020 at 21:31:58 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Leaking hydraulic pump assembly drain plug bolt
  • The test port is not taper pipe thread. It is 1/2-20 UNF and the plug is a standard fine thread cap screw with sealing washer. Screwing a pipe plug into the test port is an easy and quick way to crack the base of the pump.

    TOH

    Travis Webb (UT)    Posted 04-07-2020 at 10:20:51 [URL] [DELETE]        [Reply] [Email]  
  • Re: Leaking hydraulic pump assembly drain plug bolt
  • This "sealing washer"...any idea on the size, type, where to buy, etc.? I looked the IOT repair manual, and the part number it listed, I found on New Holland's site for $25/pc.

    Charles    Posted 04-05-2020 at 05:51:09 [URL] [DELETE]        [Reply] [Email]  
  • Re: Leaking hydraulic pump assembly drain plug bolt
  • sorry! Intent was just that. Right screwm and thread checking

    TheOldHokie    Posted 04-04-2020 at 20:59:46 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Leaking hydraulic pump assembly drain plug bolt
  • What bolt are we talking about? I'm guessing you mean the plug in the test port - right front corner of the pump. It should have a copper sealing washer on it. If that is present and it's still leaking I would suspect a cracked pump housing.

    TOH

    Travis Webb (UT)    Posted 04-04-2020 at 21:45:38 [URL] [DELETE]        [Reply] [Email]  
  • Re: Leaking hydraulic pump assembly drain plug bolt
  • Attached is a pic of the bolt in question. I don't believe it has a washer...

    TheOldHokie    Posted 04-05-2020 at 05:52:24 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Leaking hydraulic pump assembly drain plug bolt
  • That is the test port plug. It is supposed to be a 1/2-20 hex head bolt with a sealing washer under the head. If the washer is missing that might be the cause of your leak but I would expect it to be a slow drip not a stream. Can you post a picture of the plug? I dont want to be an alarmist but it sounds like someone may have replaced the bolt with a pipe plug and cracked the pump housing. Hope that is not the case.

    TOH

    Travis Webb (UT)    Posted 04-05-2020 at 11:08:11 [URL] [DELETE]        [Reply] [Email]  
  • Re: Leaking hydraulic pump assembly drain plug bolt
  • Pic 1

    Pic 4

    Travis Webb (UT)    Posted 04-05-2020 at 11:05:14 [URL] [DELETE]        [Reply] [Email]  
  • Re: Leaking hydraulic pump assembly drain plug bolt
  • Here are a few pictures. One of them shows what appears to be a surface crack, that I didn't notice until this morning...I'm assuming that is my problem...

    TheOldHokie    Posted 04-05-2020 at 12:29:30 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Leaking hydraulic pump assembly drain plug bolt
  • Washer is missing. I would put one on and check again. Hard to tell if that is a crack but now that you are looking for it you should be able watch it under pressure (raised weight on lift) and see if the flow is coming from that area. Just how much flow are you getting - drip or stream?

    Travis Webb (UT)    Posted 04-05-2020 at 13:00:06 [URL] [DELETE]        [Reply] [Email]  
  • Re: Leaking hydraulic pump assembly drain plug bolt
  • Thanks...will get a washer tomorrow and check it.

    I don't think the picture of the crack came over, so here it is. The fluid is streaming out, as if the bolt isn't there.

    Travis Webb (UT)    Posted 04-05-2020 at 13:57:47 [URL] [DELETE]        [Reply] [Email]  
  • Re: Leaking hydraulic pump assembly drain plug bolt
  • Here's a closer picture of the crack. Also, I have a video I can email as well. I did some testing, and the leak really starts when I lift the 3-point arms up; when I put them down, the leak stops, or slows drastically. It also seems to be leaking mainly from the back, where the silver meets the red paint; possibly a gasket?

    TheOldHokie    Posted 04-05-2020 at 14:59:43 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Leaking hydraulic pump assembly drain plug bolt
  • Now that is what I was expecting. Someone probably screwed a taper pipe plug in there and split the boss. Little to no pressure there until the lift is raised. If it were me I'd be researching aluminum braze or Muggyweld. The threads are probably munged as well so thread repair insert is probably going to be needed. Good news is pumps are plentiful and not real expensive.

    TOH

    Travis Webb (UT)    Posted 04-05-2020 at 15:14:44 [URL] [DELETE]        [Reply] [Email]  
  • Re: Leaking hydraulic pump assembly drain plug bolt
  • Thanks! Would JB Weld work? Is it worth trying to fix, or should I buy a new pump and be done?

    TheOldHokie    Posted 04-05-2020 at 15:28:31 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Leaking hydraulic pump assembly drain plug bolt
  • JB Weld is not going to hold 1500 PSI. If it were mine I'd be looking for a cheap pump but I would not rule out trying a repair with aluminum brazing rod. Basically a question of how deep your pockets are and how much time and effort you want to expend.

    TOH

    Travis Webb (UT)    Posted 04-05-2020 at 18:00:18 [URL] [DELETE]        [Reply] [Email]  
  • Re: Leaking hydraulic pump assembly drain plug bolt
  • Great, thanks. What are your thoughts on buying a used pump housing, and putting my existing used parts in it? Or should I just buy a new pump for $500?

    TheOldHokie    Posted 04-05-2020 at 18:39:48 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Leaking hydraulic pump assembly drain plug bolt
  • That's a personal decision.

    TOH

    Travis Webb (UT)    Posted 04-05-2020 at 19:21:32 [URL] [DELETE]        [Reply] [Email]  
  • Re: Leaking hydraulic pump assembly drain plug bolt
  • Thanks. If I decided to try to braze it, is the trans fluid flammable? Should I remove the pump first?

    TheOldHokie    Posted 04-05-2020 at 20:04:15 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Leaking hydraulic pump assembly drain plug bolt
  • Oil is flammable. You need to get the crack clean and grease/oil free. I cant see any need to remove the pump ss long as you can get it cleaned up.

    Travis Webb (UT)    Posted 04-13-2020 at 13:45:31 [URL] [DELETE]        [Reply] [Email]  
  • Re: Leaking hydraulic pump assembly drain plug bolt
  • Tried to braze it, but no luck. Look at it closer, and the threads are cracked. I ordered a new pump, and pump base gasket. My understanding is that I drain the fluid, remove the PTO shaft from the rear of the tractor, unbolt the pump and drop it out. To replace, I would remove the inspection doors on each side, line up the lever with the plunger, and bolt the pump back in; replace the PTO shaft, and fill up with new fluid. Is that right? So my parts list would be a new pump, PTO gasket, two inspection door gaskets, 3 drain plug gaskets, and a pump base gasket. Am I missing anything?

    Tom    Posted 04-05-2020 at 11:22:07 [URL] [DELETE]        [Reply] [Email]  
  • Re: Leaking hydraulic pump assembly drain plug bolt
  • If that is a crack and it does not go into the threaded area, a good welder might be able to TIG weld it.

    Charles    Posted 04-04-2020 at 20:03:25 [URL] [DELETE]        [Reply] [Email]  
  • Re: Leaking hydraulic pump assembly drain plug bolt
  • Needs a new gasket (buy make your own any auto supply). or buy tub of gasket "Form a seal"
    I hope you meant bottom plug, which would leak all time, or do you mean bolt on side plate. If side hole is problem check your fill level. When Hydraulic cyclinder goes down, the oil level increases in the case, causing the leak out the side bolt.
    HTH
    Charles

    JMOR    Posted 04-04-2020 at 23:37:14 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Leaking hydraulic pump assembly drain plug bolt
  • " When Hydraulic cyclinder goes down, the oil level increases in the case, causing the leak out the side bolt.
    HTH"
    Are you joshing us? One cup of fluid is going to change the level in 5 gallons by any significance??!!!!??

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