Drain or Pump out the old oil?

   / Drain or Pump out the old oil? #1  

rScotty

Super Member
Joined
Apr 21, 2001
Messages
8,366
Location
Rural mountains - Colorado
Tractor
Kubota M59, JD530, JD310SG. Restoring Yanmar YM165D
I've never really enjoyed crawling under a car or tractor to gravity drain the oil. Even if it goes right it is still a bit of a mess.

So recently I've been wondering....Why not pump the old oil out the filler hole instead? Clean and simple - and easy to put the exact same amount back in.

I wonder how many mechanics do it this easier way, and what you've learned along the way?
rScotty
 
   / Drain or Pump out the old oil? #2  
I did my cruising boat that way for years ( had to of course). Never liked the vacuum oil sucker-waaay to slow ( even with pre-warmed oil). The small size of the suction tube that will fit down a dipstick greatly limits the flow.

Even a powered oil extractor is going to suffer from the size of suction hose issue. If you could adapt a larger suction hose, it’d be a great improvement.
 
   / Drain or Pump out the old oil? #4  
Even if you could pump it out the dipstick hole at the same speed I'd worry whether I'd removed most all of the oil. Pulling the drain plug I'm pretty sure gets more old oil out. If you have an engine with a turbo I'm pretty sure the extractor is out of the question.
 
   / Drain or Pump out the old oil?
  • Thread Starter
#5  
You still have to crawl under the machine to change the filter, which IMO is far messier than pulling out a drain plug…
Even if you could pump it out the dipstick hole at the same speed I'd worry whether I'd removed most all of the oil. Pulling the drain plug I'm pretty sure gets more old oil out. If you have an engine with a turbo I'm pretty sure the extractor is out of the question.

Yes, changing the engine oil filter is pretty easy on the Kubota because it is above the sump level anyway. If you let it set all night you can pull the filter without losing even a spoonful.

But the (3) hydraulic filters are underneath. I'm not sure why they are made that way except "it's always been that way". They would be much easier to deal with if they were up at waist level.

I'm not so concerned with getting all the old oil out. Drain plugs do better, but still leave lots.
Yes, most of our equipment has turbos. Why would that make a difference?

rScotty
 
   / Drain or Pump out the old oil? #6  
I doubt a pump would do as well as removing sludge and particles at the bottom of the sump as just using the drain plug. The pump and hose would also get dirty resulting in something else to clean and store.

I'm not a fan of the twin sump on my L2501 resulting in two oil drain plugs to deal with.
 
   / Drain or Pump out the old oil? #7  
As much as it's not fun I think you are better off spending your energy making the existing method easier for yourself
 
   / Drain or Pump out the old oil? #8  
I've never really enjoyed crawling under a car or tractor to gravity drain the oil. Even if it goes right it is still a bit of a mess.

So recently I've been wondering....Why not pump the old oil out the filler hole instead? Clean and simple - and easy to put the exact same amount back in.

I wonder how many mechanics do it this easier way, and what you've learned along the way?
rScotty
Crawl under and drain it, best way to get everything out. i do my oil changes when the engine is hot.
 
   / Drain or Pump out the old oil?
  • Thread Starter
#9  
Crawl under and drain it, best way to get everything out. i do my oil changes when the engine is hot.

Could be, but I can't help speculating.

In my repair shop, I used to drain customer's oil hot. And I couldnt help but notice that on engines where I had to pull the oil pan that it was always full of crud. In most, draining the oil hadn't move the sediment at all.

Then later on when I was brewing some beer and needed to change containers I realized that there is no reason to expect a bottom drain to pull fluid laterally across the bottom of the pan. A bottom drain picks up some sediment, but leaves most of it. I ended up picking up more sediment with sloppy siphon hose technique.

It took awhile for my mind to put it together, but now that it is oil change time again I've begun to think about engine oil and thinking about what I actually know and what I've always just sort of believed. Maybe there is a better way.

Some of the European diesel engines - think Mercedes Sprinter - have a ridiculous long interval between oil changes. What else might I be missing?
rScotty
 
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   / Drain or Pump out the old oil? #10  
Don't have to crawl under my tractors, they sit high enough I can access the drain plugs by bending over.
 
 
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