1. carguy300

    carguy300 Member

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    After getting 300 running again after sitting several months, oil pump does not seem to be pumping. How can I reprime it?
     
  2. 413

    413 Active Member

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    Remove distributor
    Remove oil pump drive shaft
    5/16” hex rod in drill put it down the hole until it goes into the gear.
    Turn on drill counterclockwise

    if it’s making pressure it will slow down the drill some, depending on the drill.
     
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  3. carguy300

    carguy300 Member

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    Thanks. I'll give it a shot
     
  4. Davea Lux

    Davea Lux Old Man with a Hat FCBO Gold Member

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    First check the dipstick to be sure the oil has not leaked out somehow.
    There are several reasons why the pump won't prime. Have you checked the condition of the timing chain. A failing timing chain will throw plastic debris into the pan and clog up the pickup screen for the pump. If that has happened, you are going to have to pull the pan to clean up the screen and replace the timing chain.
    The pump may be priming, but you have no oil pressure. On an engine that sits, sometimes the valve guides will rust up and a push rod will bend or break. This can cause a lifer to pop up out of the galley and result in no oil pressure.
    A defective oil pressure sending will also give the appearance of no oil pressure. Proceed as noted above with the drill and shaft. Be sure to mark the position of the intermediate shaft and check the hex base to be sure it has not broken off. The intermediate shaft has to reinstalled in the some position or you distributor clock will be off. If the pump still does not prime you have probably got a clogged screen or a thrown lifter. RB series engines rarely have pump failures.

    Dave
     
  5. Big_John

    Big_John Illegitimi non carborundum FCBO Gold Member

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    A loose wire from the sender hanging and shorted to the block (or something else) will turn the oil light on too.
     
  6. PH27L7

    PH27L7 Member

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    As stated mark your intermediate shaft (gear position). I use lock ring pliers like the one shown to remove. Also mark your distributor to block position so as not to disturb timing. Last make sure your rotor position is the same so as not to get 180 degrees out. Some quick pics can help you remember.
    g409pwildepliers.jpg
     
  7. 66 Monaco 500 365

    66 Monaco 500 365 New Member

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    If you don't want to pull the distributor and middle shaft to get to the hex into the oil pump, since the pump is external, you can unbolt it and fill it with petroleum jelly to help it pull prime.
    Make sure there is as much oil in the filter as possible to make the delay shortest possible before it gets oil pressure.
    To get the motor turning as fast as possible, pull out the spark plugs.
    My $.02
     
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  8. carguy300

    carguy300 Member

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    Sometimes $.02 is all a man needs! Thanks. Any idea helps.
     
  9. moper

    moper Well-Known Member

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    Another $.02...
    The starting circuit is not designed for steady turning of an engine. It’s designed for bursts of high draw until the engine turns itself. By using the starter to try and prime it you risk electrical issues including burning out the starter or cables. Depending on the camshaft and length of time without oil you also may risk wiping out a lobe. Disregard if it’s a stock or high mileage deal.
    There’s a reason for priming shafts.
     
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  10. 66 Monaco 500 365

    66 Monaco 500 365 New Member

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    I totally agree, but I've had to help more than a hand full of people that have removed the distributor (or intermediate shaft) and never got the engine to run again, because the distributor is out of phase. In my experience, it should only take 10 to 15 seconds of cranking to get pressure when the plugs are out, especially if the pump has Vaseline in it and the filter is near full.
    If static timing a engine is in their wheelhouse, then pulling the intermediate shaft is absolutely the right way to do it, or of the engine has just been rebuilt and still on the engine stand.
     
  11. HWYCRZR

    HWYCRZR Senior Member FCBO Gold Member

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    Mark the distributor placement with a sharpie or chisel/scribe to facilitate close timing on re install. Take a picture of the rotor placement, or mark it. Don’t turn the engine over while it is out. It it will go back in with the same timing as you left it.
    I cut off a 12” chunk of my dry wall/ plaster mixer shaft. It had a 1/4 hex shaft that fit perfectly. Put it in my cordless drill made sure it was going counter clockwise and spun it up until I had pressure. I put a cheap mechanical gauge in while I was spinning it up to monitor and see how much pressure was building.
    6544CEB2-0E0D-4DFE-B855-96CEDBA0E480.jpeg
     
  12. twostick

    twostick Senior Member

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    What makes you think it isn't pumping?

    Kevin
     
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  13. carguy300

    carguy300 Member

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    It went down back before thanksgiving last year. Had bulkhead melting issues, replaced, new harness.Finally got back together a month ago, got it to start, but has mechanical clatter, oil light wont go out. Tried few times, several seconds each. Did not have this issue before it went down. It did have a major backfire through exhaust while starting the first time, so not sure if that did damage. Havent pulled valve covers yet to ck pushrods or lifters.
     
  14. 413

    413 Active Member

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    Slide a space heater under the pan and warm up the oil for 20 minutes. You have to run it more than a few seconds, give it 15 seconds.