Fluid changes using a drill pump or some other electric pump

Certainly with regards to the engine, it is better to do a full drain of the old engine oil.

Regarding the transaxle, there is no dipstick so you need to work with the drain and fill plugs which require you to get under the car.

 

Still have to get underneath for the oil filter removal.

Not necessary to put the Prius on ramps for oil change. I jack up the front using hydraulic floor jack. I jack it up for years now using the front pass side tow hook under the car. Then put jack stand under the jack edge below the door. And then leave the jack there too. Plenty of room to pull the filter and the oil pan bolt.

 

Use a Pela suction pump for the oil. Filter can be removed without raising the car. I do it all the time.

 

I've tried removing the filter with no jack and just can't get under there. The car is really low in the front as we all know.
I agree with Pat though I don't think your getting all the bad stuff out just pumping it out.

 

I think the pump is fine. There are all sorts of specialized fluid change pumps , the ones I have seen look like a giant bicycle tire pump. Mercedes pumps it out at the dealer now. Too much risk of killing the oil pan threads. A new oil pan will cost you a bundle. If you really want to get sludge out of a high mileage car you need to pull off the oil pan. Pumping out the oil removes most of the old oil but not all. Draining the oil removes more of the oil than pumping but still not everything.

 

I agree the pump is not bad at all very convenient but you still have to remove the filter so your under there anyway. No way am I putting good oil back in with a 5-10K oil filter still in the motor. So what am I saving? The filter is a mess so then removing the pan bolt is easy comparatively. If you can get under there and remove the filter without a jack the pan bolt must be much easier.

I would imagine sludge would build up much faster if not allowed to drain out now and then. That's the whole idea of a drain.

And oil pan bolts are usually sacrificially soft so not to ruin the pan. You really have to go out of your way to mess up oil pan threads.

Good idea to replace that oil pan bolt now and then too. I'm on my second bolt with my Prius. It was $8 at the dealer.

 

i saw an electric pump at lowe's for lawn tractors. not sure if the hose would fit in the prius dipstick or not.

 

This one for example
Motive Products 1708 Vehicle Fluid Power Extractor System:Amazon:Automotive

Or this one.
Mityvac 7201 Fluid Evacuator Plus:Amazon:Automotive

I have used the second one a few times to pull ATF out of cars that are overfilled. It has a thin tube that is somewhat rigid and goes to the bottom of a dipstick easily.