DIY Oil change pump build

[sailah]

The discussion in another thread prompted my mind spinning a solution to the inevitable mess in changing oil on my boat. I've managed to get more efficient using a cheap Harbor Frieght hand pump but storing the pump was messy and it just took far longer than I wanted.

I have been successfully using a 12v fuel polishing system on Siena for 2 years now and while it did take some work, it works great and the redundancy for fuel delivery in case of a engine pump malfunction was a nice bonus.

Decided to tackle this oil change pump thing once and for all.

My first thought was to use a 12v scavenger oil pump found all over the Internet for about $60. Reading the reviews it doesn't appear to be that robust a pump. I also don't like wiring up another 12v circuit for once a year duty. I remember reading about using a small block chevy oil pump (Melling M55) that guys were modifying to pump veggie oil for use in their trucks. The mods are fairly simple so I'm going to give it a whirl.

It involves drilling, tapping, maybe some welding or JB welding. I plan to take it a few steps further for my convenience. One is to make a mount so I can secure to engine room wall. Second is to modify the pump shaft to 3/8" so I can utilize my cordless Makita drill I keep aboard for motive power. These pumps are made for being inside a Chevy oil pan so they do not have a seal on the shaft. Users report a slight weeping at shaft seal. You can supposedly seal with axle grease or hold a rag to catch a few drops. I plan to bore the housing and install a shaft seal but that's probably beyond DIY for most folks. I'll try and make my version then another with basic hand tools to see if it can be done both ways.

I plan to plumb this directly to my Westerbeke oil pan drain line but with a diverted valve. The other port will be connected to a rubber hose wand so I can drain my transmission into engine room drain pan and then suck it out using pump.

Pump has been ordered ($23.50 on Amazon) and I'll document the steps for anyone else interested in this. I already have the ability to pump diesel using my polisher but since this is a gear pump, it'll pretty much pump anything if you wanted to think of other ways to use it.

These aren't my photos but representative of what the mods are like

[captd44]

This type pump will need to be mounted below pan or level when empty. It is not a suction pump.

[jamhass]

Way too much work. Just use one of these if you want to go that way.

https://www.amazon.com/Lanchez-225GP...rds=drill+pump

[sailah]

Are you sure about that or are you hypothesizing? Every article I've read indicates that these are indeed self priming and capable of tremendous suction.

That assumes the gears are wet to create the seal.

https://www.youtube.com/watch?v=sVQpwcEMpz8&t=44s

http://www.liquiflo.com/v2/files/pdf...ump_Basics.pdf

My ideal mounting place will be directly beneath my polishing pump, that way I can easily manipulate drill and hold wand to suck oil out of fiberglass pan with other hand.

[leboyd]

The plastic one might work for a while, but I don't think it would last long in my clumsy hands.

I'm interested in the results of your build and test, as I have interest in doing something similar.

[sailah]

Originally Posted by jamhass

Way too much work. Just use one of these if you want to go that way.

https://www.amazon.com/Lanchez-225GP...rds=drill+pump

I specialize in way too much work

Have you ever used one of those drill pumps? Those are useless with just water.

[jamhass]

If you want it mounted, try this.

https://www.amazon.com/Milescraft-In...l+pump+for+oil

For once or twice a year, it'll last years, and cheap to replace if ever.

[jamhass]

Originally Posted by sailah

Have you ever used one of those drill pumps? Those are useless with just water.

Yes, I have, with good success. They do like to be primed. They are simple impeller pumps, just like your raw water pump, just with plastic bodies. There are more expensive varieties. The only issue I have had with them is the impeller gets stiff if it just sits for too long, but by that I mean a couple of years.

[sailah]

I've bought a couple drill pumps over the years and been seriously underwhelmed at their performance. I assume if they were a contender the WVO oil guys would be all over them. All my machining knowledge points me to using gear pumps for oil.

Anyways, I'm going to try out the idea, I've already ordered all the parts, If it's a failure I'll admit it.

EDIT: I just ordered the above drill pump for comparison sake. Will do a head to head pumping my 5 gal waste oil container I keep in the barn to bring to recycling. We'll see which does better with a 3 gal mixture of (90wt gear oil, 15-40 diesel, hydraulic fluid, transmission fluid at ambient temps)

[jhulmer]

Originally Posted by sailah

I specialize in way too much work

Have you ever used one of those drill pumps? Those are useless with just water.

Yeah they're crap! been there done that got the oils stains on the sole to prove it!

I'm intrigued with your concept. This is what those pumps are born to do. they move oil quick and will last forever in that application.

Probably needs a valve between the pan and the pump. I like the idea of installing a seal. I have a machine shop so no problem for me.

I will follow your progress.

[sailah]

Originally Posted by jhulmer

Yeah they're crap! been there done that got the oils stains on the sole to prove it!

I'm intrigued with your concept. This is what those pumps are born to do. they move oil quick and will last forever in that application.

Probably needs a valve between the pan and the pump. I like the idea of installing a seal. I have a machine shop so no problem for me.

I will follow your progress.

Yeah if you have a machine shop the world is easier

Apparently the shaft is 0.483". The closest oil seal I can find easily is 1/2" nominal which needs a 0.750 bore. I don't think there is enough meat on the outside to bore that big even if there is enough stretch to seal the shaft. Could also turn the shaft down to 3/8" or possibly do the bore internally? Will see what it looks like. If it weeps a drop in the whole oil change I'm not going to even fuss with the seal and just use heavy grease on the shaft to get a seal.

My plan for the valve is to add a 3 way diverter valve and keep it on the wand port. This will isolate the oil pan drain hose from allowing the oil to flow anywhere. In reality the pump body will be above the oil line so I don't think it would drain anyways.

[oleman]

Automotive oil pumps do not have a seal on their drive shaft. They are designed to leak for self lubrication and run in the oil anyway.
Without a seal it will create a mess.
You could probably use a boring bar on a lathe and create an O-ring groove to be used as a seal BUT that simple grove will be costly if you hire it done.
I would suggest a fuel pump from a 71 series detroit diesel. It is a rotary pump at least as large as a chevy v8 oil pump.
It has seals and is a self contained pump with screw-in fittings. Externally Flange mounted to the engine. Just build a drive system, it normally drives from a drive shaft input.
It is simply a better pump. Normally produces 45-60 PSI of pressure when engine is running.

[Dockhead]

Permanently installed oil change pumps are great! We had one on the previous boat and it saved an ENORMOUS amount of mess and trouble.

Get a reversible one and you can use it to fill as well as drain.

Don't try to improvise it -- use one made for the purpose. Something like this:

Jabsco 17830 Series Oil Change Pump

Worth every penny.

[hamburking]

Originally Posted by sailah

I specialize in way too much work

Have you ever used one of those drill pumps? Those are useless with just water.

Agreed. I tried to use one to change the oil in my atomic 4 once...waste of time, money and effort.

They require something like 3000 rpm, while most drills only go 1000 rpm. If you ever did get it up to 3000 rpm, I expect it would fly to pieces.

[hamburking]

For my last few boats I've been building my own DISPOSABLE oil change pump. The whole thing costs just a couple bucks, and it goes into a shoreside garbage can the moment I'm done pumping.

The dollar store sells a popular childs water squirt toy which is a water pump. It resembles a giant crayon, about 24 inches long. It is actually a pretty well made hand pump made from inexpensive colourful plastic. It costs a dollar.

To that dollar pump I drill the tip of the cone to the same size hose I need for pumping oil. Usually about 4 feet of 3/8 inch hose will do. This will cost you another dollar, unless you already have a piece on your boat, that'll cost you nothing.

I insert the cheap hose into the cone of the cheap pump, its usually a pretty good force fit. Then I seal with....ugh...duct tape. The first layer is the seal. Then I add more layers for strength. About 10 layers is good, so you can bend and twist with no worries. At this point its good to test with water, and you'll be surprised and impressed at what a powerful pump you have built.

Don't forget to warm the oil, because thick oil is hard/impossible to pump with this device. Stick the hose in the dipstick hole, and pull the handle ....this is the suck motion. Then pull the hose out and stick it in a used water bottle or other container...and push the handle back in...and there goes the oil. It usually takes about 10 pumps to drain all the oil from a small engine.

I admit its slow. And your hands will get messy pulling the hose in and out 10 times, so it helps to have 2 people (one to pump, the other to hose). But for the once a year I change my oil, this system works very well. And like I said above, the whole thing goes in the trash when I'm done. No messy pump to store.

Yes, I really do this, and it really works. Its a $2 oil pump.

And it comes in a variety of bright colours to complement any decor.