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Subject: Oil flow mystery

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COLVIN    Posted 10-09-2020 at 07:47:19 [URL] [DELETE]        [Reply] [Email]  
  • Oil flow mystery
  • On my late 1951 8N, after draining the warm oil from the pan, letting drain well, when I go to remove the filter, the canister remains full and overflowing. To get the filter up and out takes a bit of force (and a good bit of oil spilled out) and the canister stays half full. Is this as it should be?

    Also, when the engine is warm and idling, the oil pressure gauge never reads below 20 lbs. and pins the gauge above 50 lbs. when running at medium or higher speed. It has been this way for as long as I can remember – for decades.

    Could these be related and indicate an oil blockage in a line? I really love the tractor and want it to be the best it can be. Any ideas on what to do to diagnose a problem and how to remedy it? Thanks so much for any help.

    Gaspump    Posted 10-10-2020 at 19:45:07 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Oil flow mystery
  • When changing oil some tools help. To vacate oil from a filter canister with or without a drain I use an Alemite F-105 suction gun. Very simple and handy item to have around.

    Tim Daley(MI)    Posted 10-09-2020 at 14:41:37 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Oil flow mystery
  • The oil filter canister has a brass NPT drain plug on the bottom. Try using that next time. Get engine HOT, not warm. Place drain pan under oil pan plug and under canister housing. Remove drain plugs and walk away for good half hour at least, longer if possible. Filter has small handle on top, or should. Pull and twist easy so you don't break it. Can flush canister with mineral spirits then replace plug. Clean old gasket from drain plug and mating surface. Replace with new gasket -wipe with clean oil first and tighten plug. Refill with about 3 quarts of clean oil. Start engine and check for leaks. If OK top off using dipstick gauge sight. Capacity is 6 qts but just put 4 or 5 in it for now and sneak up on it by verifying the next day. Oil gauge should read about 27 PSI at idle when warm. Older worn engines will slowly decrease PSI when running hot. Gauge should not peg at 50 under full throttle. Try removing oil line at gauge and blow compressed air thru it and try again. If same, try new gauge and maybe having oil pump rebuilt.

    Tim Daley(MI)

    John M    Posted 10-09-2020 at 22:20:37 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Oil flow mystery
  • A 1951 8N does not have a drain plug on the oil filter canister.

    COLVIN    Posted 10-09-2020 at 21:06:46 [URL] [DELETE]        [Reply] [Email]  
  • Re: Oil flow mystery
  • There is a mysterious mention of part 358042-S in the parts manual (p 89), but it does not appear on the diagram (p 88). Even though the diagram says 1939-52, it may only show the latest assembly. The brass fitting at the bottom connecting to the line to the governor does not connect directly with the interior of the bottom of the canister and cannot act as a drain. I took off the canister and the oil lines and cleaned them and there was very little thick stuff in either. It seems they just expected us to live with a cup of the old dirty oil in every new batch (or siphon/rag.) I can live with that from now on. I will pursue the high pressure issue independently. Thanks so much!

    Tim Daley(MI)    Posted 10-10-2020 at 07:05:03 [URL] [DELETE]        [Reply] [Email]  
  • Re: Oil flow mystery
  • There's nothing mysterious about these vintage parts and machines. I referenced my May, 1949 MPC to answer the drain plug item, p/n 358042-S. Forget page numbers, means nothing as it depends on which MPC you are looking at. So, it appears based on the May, 1950 MPC that the drain plug was obsoleted, most likely in April, 1950 when many major changes were made. "...It seems they just expected us to live with a cup of the old dirty oil in every new batch (or siphon/rag.)..." No. No drain plug, so why don't you loosen the oil line on the bottom at the brass inlet, p/n 9N-18679 and drain oil from there? Flush with Mineral Spirits (charcoal lighter fluid or paint thinner, same stuff), wipe with shop towels/rags, then reinsert line. Maybe I should have stated above in my method that you should relive some pressure by removing the canister lid bolt and loosen or remove lid when draining oil pan. I have an early 8N and don't bother with my drain plug anymore or muck with the line. Once filter is removed, I wipe out old remnants with rags, pour some spirits in and wipe up excess. Repeat as often as you wish. For your gauge issue, as I suggested, blow out line at gauge point, if that doesn't work, try a new gauge, if that doesn't work time to rebuild oil pump. since that requires dropping the pan, you are half way to an engine rebuild tear down so...your call. I have a few slightly used oil Pressure Gauges; I could send you one, you pay $10 to include postage. It's not rocket science. C'mon! We're talking about an oil change -how basic can you get? Some thing just require using common sense. SEE LINK from our HOW-TO's for more info.


    Tim Daley(MI)

    COLVIN    Posted 10-10-2020 at 08:32:50 [URL] [DELETE]        [Reply] [Email]  
  • Re: Oil flow mystery
  • “Forget page numbers, means nothing as it depends on which MPC you are looking at.” I think it would take a lot of searching to find a copy of the MPC other than the one I have, if it could be found at all. So the entry was indeed a mystery to me, and would be to almost everyone else, were they interested.

    “No drain plug, so why don't you loosen the oil line on the bottom at the brass inlet, p/n 9N-18679 and drain oil from there?” Because that doesn’t work: you seem not to have noticed that I said “The brass fitting at the bottom connecting to the line to the governor does not connect directly with the interior of the bottom of the canister and cannot act as a drain.” Nor do you seem to have noticed that I dismantled the whole thing.

    “It's not rocket science. C'mon! We're talking about an oil change -how basic can you get? Some thing just require using common sense.” I have always admired your competence and helpfulness Tim. Such condescension and insult as this response reflects does not become you or these forums. I think they were intended to help those who need it.

    Tim Daket(MI)    Posted 10-10-2020 at 19:14:49 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Oil flow mystery
  • MPC's can be found here in our MANUALS forum and they can downloaded for FREE. Granted we don't have all of them but all 9N/2N's are there and the MAY, 1949 one. The SEP 1952 MPC, the last 8N one issued, and the one that is copied and reprinted by many now, most unauthorized, can be found everywhere so when you say it is on page such and such, it's a moot point...

    TPD


    COLVIN    Posted 10-10-2020 at 19:26:30 [URL] [DELETE]        [Reply] [Email]  
  • Re: Oil flow mystery
  • Thanks all for spending the time to help educate me. I will pursue the relief valve spring possibility, but I suspect the gauge will be the most likely culprit. I still don't quite understand why, if working properly, the relief valve should need to open unless there were some sort of blockage that caused the higher pressure.

    I now have a 1949 8N as well, so it is good to know that the earlier MPCs are available. I'm not a very thorough searcher and all I could find was the one entitled 1939 thru 1953.

    TheOldHokie    Posted 10-11-2020 at 08:53:24 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Oil flow mystery
  • You are correct. The oil pressure relief valve is used to limit pressure at cold startup when the oil is overly thick. Once the engine oil gets warmer viscosity decreases, oil pressure falls to something below 40 PSI, and the oil pressure relief valve closes and stays closed. It is next to impossible for an L-head turning 2000 RPM to generate 50 PSI oil pressure when the engine is at operating temperature.

    TOH

    JMOR    Posted 10-09-2020 at 11:37:25 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Oil flow mystery
  • Bent wire stuck in exit hole

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