Changing the oil on the Universal M25 diesel

You don't get any help from gravity when you change the oil on the Universal M25 diesel - the oil has to be sucked out of the oil pan.

oil extractor, filter wrench and Delo 400 oil
Oil extractor, filter wrench and Delo 400 oil

Parts & Supplies

  • 4.0 qts Delo 400 multiweight oil (15-40) - $14.99, O'Reilly Auto Parts
  • Fram PH3593A Sure Grip oil filter - $3.99, O'Reilly Auto Parts
    • You can use other oil filters, but the Fram has a nice non-slip coating on the end so you don't need a wrench for removing and installing.
  • Oilsorb sheet - $.85, West Marine
  • paper towels and/or shop towels
  • quart size ziplock freezer bag
  • empty gallon jug to hold old oil
  • wide funnel to transfer oil from extractor container to jug and to refill crankcase


  • FRAM Adjustable Oil Filter Band Wrench - (swivel handle), WalMart
  • 2.9 Quart Oil Changer - $42.32, West Marine
    • 2.9 quarts Oil Changer? What? - the diesel holds 4 quarts. You can buy a much larger pump that holds all the oil, but the small one is easier for me to store.
  • Wrench

Get the old oil out of the engine

Step One - Warm engine, insert tubing

oil removal tube and dipstick
The red oil removal tube on Reality Check
  1. Start the engine and run 5 - 10 minutes, just enough to warm up the oil - not enough to get the engine hot
    • Engine temperature should be between 100-120 degrees
  2. Remove the engine compartment cover
  3. Remove the end cap of the oil removal tube with the wrench, set aside.

oil extractor
Oil changer sucking out oil

Step Two - Make all connections

  1. Insert the tube from the oil extractor pump into the oil removal tube on the diesel
    • Push it down all the way until it stops
  2. Raise and twist pump handle so it rests on the unit handle. This uncovers the pump unit's cap hole
  3. Attach the main extractor tube to the pump
    • remove the tethered cap, insert the black connection seal of the extractor tube into the unit's cap hole. Press into place.
  4. Connect the extension tubing into the main extraction tube
    • ease the main tube inside the extension tube's connector sleeve. Once inside, push hard to get a tight fit

Step Three - Operate extractor

  1. Pull up pump handle and pump several times to create a vacuum effect
    • Continuous pumping isn't necessary, but if it looks like it stops while extracting give it a few more pumps
  2. After 10-15 minutes, the container should be close to full and shut off automatically

Step Four - Hold down pressure relief valve

  1. Hold down the pressure relief valve for 5 seconds.

Step Five - Transfer oil from extractor to disposal container

  1. Remove pump extension tubing from oil removal tube on the diesel and hold the end of the tube above the extractor unit until fully drained.
  2. Remove the main extraction tube from the cap hole on the pump.
  3. Take extractor pump full of oil topside and transfer to an empty container for disposal.
  4. Repeat steps 4 through 13 because the extractor pump is too small to hold all the oil you need to get out of the engine.
  5. Put the end cap back on the engine oil removal tube.
Fram orange oil filter PH3593A
Fram orange oil filter with rubberized grip is below the blue fresh water hose. This one has some bronze paint on it from painting the engine

Change the oil filter

No matter what you do there's going to be some oil spilling on the engine when you remove the old filter. Be ready with paper towels and shop towels or some other absorbent material. Some people use diapers!

  1. Stuff some paper towels or absorbent shop towels under the filter
  2. Unscrew the oil filter very slightly - not enough to break the seal and get oil everywhere, but just enough so you will be able to unscrew it by hand.
    • If you can't unscrew the filter by hand, loosen it slightly with the wrench.
  3. Put the quart-size ziplock bag over the filter
    • The open end of the baggie should be folded back about 1/2 inch.
  4. With your finger inside the fold of the baggie, hold the bag against the engine block at the bottom of the filter.
  5. With your other hand outside the bag, unscrew the filter - keeping the filter in the bag.
  6. Remove the bag and seal - ready for disposal.
  7. Clean up the oil mess.
  8. Moisten the oil filter gasket with new oil. Easy to do with your finger.
  9. Put the new filter on by hand.
    • When the filter starts to get snug, hand tighten it a 1/4 turn.
    • Hand pressure is sufficient to tighten the filter.
oil filler cap on top of crankcase
Oil filler cap on top of crankcase

Put the new oil in the crankcase

  1. Remove the oil filler cap on top of the engine crankcase.
  2. With a wide funnel, slowly pour the new oil into the engine.
    • Refill as indicated by the full mark on the dipstick.
    • Do NOT overfill! It may not take all 4 quarts due to whatever oil is left in the engine.
  3. Replace oil filler cap. Hand tight is all that is necessary.
  4. Start engine and run only long enough to check for oil leaks and then stop the engine.
  5. Check for leaks around the oil filter.
  6. After the engine has stopped and the oil level allowed to settle, recheck the oil level and fill as required.
    • The oil level will have dropped by the amount of oil which enters the new oil filter and the amount which has distributed around the engine.
    • Do NOT overfill! Too much oil is NOT a good thing
    • The new oil mixes with the old oil that was still in the engine and becomes black right away. That's normal.
  7. Put a nice new Oilsorb sheet under the engine like the pros.

Dispose of the old oil and filter

Most marinas have a recycling area for disposal of old oil and filters. If not, check for recycling centers near you.

Oil Filter Change is on page 31 in the Universal M25 Owners Manual

Oil lubrication system info is on pages 5-7 in the Universal M15, M25 Service manual (Publication #200151)


Universal M25 Diesel

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Engine Compartment Insulation / Soundproofing

Anchor Locker





Bimini for the Boat



Edson Pedestal Controls