Pre Lube Full oil presure before starting

Discussion in 'Lawn Mowing' started by fdew, Jan 5, 2001.

  1. fdew

    fdew LawnSite Member
    Messages: 147

    Every time car nuts get together for any length of time the subject of pre lube comes up.

    They use a small pump that brings the engine to full oil pressure before starting. They also have the advantage of making remote filters easy, and provide a easy no mess, no tools, power oil change.

    Where a commercial mower is started many times a day and the oil may be changed once a week it seems like a good application. Is any one using one?

    Here are some web sites.

    Me, I built my own for one car.


    [Edited by fdew on 01-05-2001 at 10:06 PM]
  2. Likestomow

    Likestomow LawnSite Senior Member
    Messages: 997

    Hey Frank, why don't you tell us how you made it, and how one could be adapted for portable use on different mowers?

    I just changed my oil on my DC and could have used one.
  3. fdew

    fdew LawnSite Member
    Messages: 147

    You need to connect to the engine in two places. One is a no pressure oil input on a car this is the oil pan drain plug. On a mower it would be the oil drain. Then you need a pressure input. I used a “T” where the oil pressure warning light is connected. Some people use a adapter that goes between the oil filter and the engine. I wanted a setup that was not in the main oil line. That is, I did not want all the engine oil to be required to run through my plumbing and my pump. This was a personal choice. I see no inherent problem with running all the oil through the external pump as long as the pump will allow full flow when off..

    I am cheep so I used a low pressure fuel pump from a VW Golf (Used) If you use a fuel pump make sure it is one of the low pressure ones (About 35 PSI) (The older fuel injections systems used about 80 PSI)

    Install a “T” and a shut off valve in the high pressure line going back to the engine (The output of the pump) To change oil connect a short length of hose to the valve, open it and turn on the pump. The no tools, no mess, no under the car oil change may be the best part.

    BTW When I was building mine I looked at a Northern tool 12 volt water pump that produced 40 PSI Max.. It cost $65. I didn’t try it. I used the fuel pump instead.

    NOTE You are playing around with your engine life blood here. Make sure your hoses and connection are first rate, Test everything, have a pressure gauge installed or a “oil sentry shut” off if you use a make shift pump like I did make sure it will allow flow through when off if it is in the filtered oil line. If it is not in that line then make sure there is a valve in the pump (or add one) to prevent the pressurized oil from flowing back through your pump to the pan.

    In a mower that already has a setup for a remote filter you would already have the two hoses you need.

  4. thelawnguy

    thelawnguy LawnSite Silver Member
    Messages: 2,411

    Just another gimmick to go wrong. Change the oil in your car regularly and the engine will last 150k+ miles. Chances are every one of those guys with prelube setups sells the car long before that mileage anyway. Whats the point???

    Oil filters have an anti drainback valve to keep the oil in the passages so with quality oil startup wear is minimal at best. The big lack of oil problem, is when people (or jiffy lube) change oil filters and dont pre-fill them and let em sit for 10 minutes before slapping them on an engine.
  5. fdew

    fdew LawnSite Member
    Messages: 147

    I think you make a very good point regarding cars (and trucks) but I was thinking of commercial mowing equipment. Many people on this list have spoken of good mowers with worn out engines.
    There is no doubt that these things save wear. The only question is weather they save enough wear to be worth the price and the 5 sec wate each time the engine is started.
    I know that if I had to change the oil on my car every 50 hrs I would install one just to make that easer.


    [Edited by fdew on 01-06-2001 at 04:55 PM]
  6. thelawnguy

    thelawnguy LawnSite Silver Member
    Messages: 2,411

    I think most of the wear on lawn equipment engines is due to dirt and grit entering the engine and oil thru neglected air and oil filter change intervals, rather than dry starts. look at the environment these things run in, and its a wonder they last as long as they do.
  7. Cleve

    Cleve LawnSite Senior Member
    Male, from Rockmart, GA
    Messages: 404

    The prelube is a great idea. Problem is, the commercial unit I looked into a few years ago cost over $500 and used a engine starter as the power source for the pump. I just find it hard to believe a "fuel pump" would come anywhere close to being able to move oil (especially cold oil) at a rate that would get the oil to all the critical points and under pressure. I have a powerstroke diesel in my truck and wanted to install one in it. I also have a walker mower with a diesel that could benefit from this. Just don't believe the cost would justify the possible life increase on either. I do believe the starting of any engine is where major wear occurs. As far as the gasoline engines on my other equipment, I believe replacing the engine would be cheaper if it fails.
    Just my opinion. Cleve....
  8. fdew

    fdew LawnSite Member
    Messages: 147

    Cleve, This system uses no pump at all!

    It cost $395

    ( Problem is, the commercial unit I looked into a few years ago cost over $500 and used a engine starter as the power source for the pump)


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