Dumb quesrion... Oil drain

[Sidnewport]

I have a Universal M12 with an oil drain hose. The hose has a 1/4 npt fitting on the end. Is there presumably some sort of suction fitting I can use to pull the oil out, or do I just let gravity do the job. It doesnt seem like there is enough vertical clearance to just catch the oil. Do I just use a shallow automotive oil drain pan, or what?

My previous boat had a Volvo engine where it was easy to suck the oil out through the dipstick hole, but it had a larger dipstick.

 

[Loren Beach]

Our prior Universal M25XP had the factory-option drain hose that was led up from a banjo fitting on the bottom of the pan. While there was no provision to screw on a suction hose to withdraw the old oil, I used the suction tube on my vacuum oil changer with no problems for over 20 seasons. Our current Betamarine25 came with a built-in hand pump to suck up oil and directly discharge it into a container. Super Handy.
I have lots of friends that have successfully slurped their old oil out via dipstick for decades and they seem to have no complaints.

I would note that the vacuum pump we have used for decades has a slender tube/wand just for that purpose. West Marine sells one, albeit at 6 quart sizing, up from our old 4 quart version.

 

[Sidnewport]

This boat has a fitting at the end of the hose, and so I am expecting that ther is a suction pump rhar would fit that fitting. I have seen several extension hoses that seem to have that fitting, but is there some kind of adapter that will screw a plain pump hose to that fitting?

 

[Sidnewport]

This boat has a fitting at the end of the hose, and so I am expecting that ther is a suction pump rhar would fit that fitting. I have seen several extension hoses that seem to have that fitting, but is there some kind of adapter that will screw a plain pump hose to that fitting?

Correction, the hose fitting appears to be a 1/8 npt female fitting. The standard tubing coming from my vaccum exraction pump is 3/8 OD tubing. I was thinking of wrapping it in electrical tape as a seal, but I would like a better way to get the oil out.

 

[Loren Beach]

I would suggest pushing your smaller tube down the engine drain hose until it bottoms out at the pan fitting. Pull it back about a half inch. Then operate the suction pump.

 

[Joliba]

We use a “drill pump” and attach the hose using a plastic hose barb to threaded male connector. Simply remove the male plug from the engine sump drain and connect the male fitting on the pump hose to the threaded female fitting. We stick the output hose into a gallon plastic bottle (old empty oil container.) Our plastic fitting came with the drill pump. But you could buy one online easily if there isn’t one included.

 

[Sidnewport]

That sounds like what I used to do through the dipstick, but this boat is set up differently, with a drain hose at the bottom. Apparently you open up a bolt at the bottom that allows flow out from a 90 degree fitting into a drain hose. It could drain by gravity, but there does not seem to be enough vertical for a pan underneath to catch it, so suction would make sense.

The dipstick on this engine is tiny, and you probably could get a thin tube through there, but Universal provides the drain hose that is supposed to make the job easier.

I don't know if this is normal, but the drain hose on this boat is actually a hose within a hose. The outer hose is a normal 3/4" water hose, but inside that is a thinner rubber hose with a 1/8 NPT female fitting on the end, capped by a plug. It appears that this fitting is supposed to mate with some sort of suction pump. I am not sure how these hoses are attached at the engine drain, but there should be some kind of suction pump that mates to the 1/8 in female fitting.

Your suggestion to push a pump tube through the drain would not work as the hole in the fitting is very small. They clearly expect some kind of adapter. It the inner hose were to be removed and you pushed the pump tube in through the hose, it would not be likely to get all the oil out of the hose, and it would create a mess. There has to be a clean way to do this.

 

[Joliba]

Apparently you open up a bolt at the bottom that allows flow out from a 90 degree fitting into a drain hose.

No.
The inner hose you describe is already connected to the oil sump. Simply connect the inlet hose for your drill pump to the threaded fitting on the tip of the hose from the engine. You can buy a plastic hose barb to male NPT connector of the appropriate size from US Plastics online.
The outer hose you describe is simply something Ericson taped around the oil sump hose as chafe protection. It has no other function.

 

[Sidnewport]

No.
The inner hose you describe is already connected to the oil sump. Simply connect the inlet hose for your drill pump to the threaded fitting on the tip of the hose from the engine. You can buy a plastic hose barb to male NPT connector of the appropriate size from US Plastics online.
The outer hose you describe is simply something Ericson taped around the oil sump hose as chafe protection. It has no other function.

Glad I asked. I had sort of assumed that about the outer hose. But you are telling me that if I were to loosen that 3/4 inch bolt head at the bottom of the fitting, I would get an enormous mess. Phew! That was a close one.

The hose seems to be a bit above floor level. Shouldn't there be something at the bottom of the oil sump preventing the oil from filling the hose if you stretched it out (and possibly leak into the cockpit floor)? I could have sworn that the bolt at the bottom was a valve to let the oil out into the hose. But I will take your word on that.

So, one more question... is that a 1/8" NPT plug at the end?

 

[Loren Beach]

More oil drain info here: https://ericsonyachts.org/ie/threads/out-there-revival-e35-3.22094/page-2#post-182374

 

[Kenneth K]

I have that same black hose coming off the banjo fitting and the same brass, threaded fitting on the free end. For pumping oil out, I remove the brass end-plug and insert the small diameter plastic tube from my West Marine oil extraction pump directly inside the black hose as far as it will go. It fits tightly enough to hold a vacuum seal.

I've always assumed purpose of the brass end-fitting was just to hold the screw-cap in place to form a tight seal (since the oil pan likely pressurizes some due to blow-by).

 

[Joliba]

So, one more question... is that a 1/8" NPT plug at the end?

I don’t recall the size. I believe it is bigger than 1/8”, likely 1/4”. But I’m guessing so you’ll have to measure.
If you can wait a few days, we will likely be changing our oil this Friday and I can take pictures or a video of what we do. The threaded fitting makes a leakproof connection with a bigger inner diameter than if you stuck a tube into the sump drain hose as Kenneth K suggests. We do it with no mess. If you hold the end of the tube up higher than the engine sump when you take the cap off, no oil will run out. You can safely unscrew the cap with a small wrench to measure it.

 

[Sidnewport]

I don’t recall the size. I believe it is bigger than 1/8”, likely 1/4”. But I’m guessing so you’ll have to measure.
If you can wait a few days, we will likely be changing our oil this Friday and I can take pictures or a video of what we do. The threaded fitting makes a leakproof connection with a bigger inner diameter than if you stuck a tube into the sump drain hose as Kenneth K suggests. We do it with no mess. If you hold the end of the tube up higher than the engine sump when you take the cap off, no oil will run out. You can safely unscrew the cap with a small wrench to measure it.

I am asking about the size in order to purchase an adapter, to make sure it fits. It looks like a 1/8 NPT. A 1/8 NPT fitting is about 7/16 in diameter... the 1/8 refers to the ID of a steel pipe that it would fit to.

 

[Kenneth K]

Yeah, the threaded end-fitting vs the hose-within-a-hose is pretty much "six of one vs a half-dozen..."

But a small diameter suction hose is good for other things, too. Occasionally, after draining the banjo-fitting line, I'll run the hose down the dip-stick tube as well, to see if I can get any additional engine oil out. It's also useful for draining the transmission fluid from the Hurth filler/dipstick port. I don't think a larger diameter hose would fit into the hard-to-reach corners of the transmission case very well.

 

[Joliba]

am asking about the size in order to purchase an adapter, to make sure it fits. It looks like a 1/8 NPT. A 1/8 NPT fitting is about 7/16 in diameter... the 1/8 refers to the ID of a steel pipe that it would fit to.

Though I haven’t looked at that fitting for a while, in thinking about it, I believe you are correct that it is a 1/8 NPT thread. You will have to determine the size of the hose barb end of the coupler after you get a pump. Ours came with the coupler that was the correct size when we bought it about 10 years ago.

Yeah, the threaded end-fitting vs the hose-within-a-hose is pretty much "six of one vs a half-dozen..."

But a small diameter suction hose is good for other things, too. Occasionally, after draining the banjo-fitting line, I'll run the hose down the dip-stick tube as well, to see if I can get any additional engine oil out. It's also useful for draining the transmission fluid from the Hurth filler/dipstick port. I don't think a larger diameter hose would fit into the hard-to-reach corners of the transmission case very well.

I have liked using the dipstick tube for engines in previous boats. However, the Universal 5432 in our boat holds an absurd 9+ quarts of oil! (Yes, almost 2 1/2 gallons.) The larger tubing makes quick work of it.
For my transmission fluid, I use IV tubing and a 60ml syringe. I can clearly see how much I get out.

 

[GrandpaSteve]

I am asking about the size in order to purchase an adapter, to make sure it fits. It looks like a 1/8 NPT. A 1/8 NPT fitting is about 7/16 in diameter... the 1/8 refers to the ID of a steel pipe that it would fit to.

That fitting is just a cap, you undo it and push the hose that comes with a oil vacuum pump like west marine sells all the way to the bottom and start pumping.

 

[Sidnewport]

That fitting is just a cap, you undo it and push the hose that comes with a oil vacuum pump like west marine sells all the way to the bottom and start pumping.

I guess there are different setups. Some apparently are capped open tubes and you can run a hose inside. Others like mine have fitting with a tiny hole inside that is designed to be a vacuum fitting. No way could I fit a vacuum hose through that hole. I am getting a screw-in quick connector for my rigid vacuum pump hose. If that does not work I will get a hose barb and a flexible hose. If neither works I will cut off the end fitting and put the hose inside like many of you have done.

 

[Sidnewport]

Apparently there are no dumb questions. Glad I found this forum.

 

[Joliba]

We changed our Universal 5432 engine oil today. Today we did it very neatly with no oil mess. I have included photos. (For those who are not accustomed to changing oil I will describe the process.)
1. Run the engine to warm up the oil so it will flow easily.
2. Remove the cap from the oil sump drain hose. (The male fitting measures .53" consistent with a 1/4NPT pipe thread fitting) Photo1
3. Screw in the threaded fitting on the drill driven pump inflow hose. Photos 2 & 3
4. Photo 4 shows our drill driven pump.
5. Place the outflow hose into an empty container. Photo 5
6. Open the oil fill cap on the engine to let air in, allowing the oil flows easily.
7. Pump out all of the oil.
8. Remove the pump and replace the drain hose threaded cap.
9. Remove the oil filter. I hold a 1 gallon Zip-lock bag over the old filter and snugly against the engine. I allow the oil in the filter and the filter itself to fall into the bag. Though I placed a paper towel beneath, today I managed to do it without dripping any oil. Usually a little gets away.
10. Coat the seal on the new filter with a bit of oil and screw it on snugly hand tight. Never over-tighten it.
11. Refill the engine with fresh oil. Our crazy engine took over 9 1/2 quarts!
12. Run the engine for a few minutes, then top off the oil to your desired level on the dipstick.

 

[Loren Beach]

Mike, you are one of the sailors that make this one of the most useful sailing sites on the 'net!

Steps 9 and 10, are how I do that, as well.