Pumping out oil from dipstick

[Dave neo]

using a vacuum pump canister with screw-on connection and with vacuum created wondering if I should loosen the oil fill cap to avoid damage or does that kill the whole idea of vacuum pump? First time using setup - a thanks for any comments

 

[flashback]

I do but I don't think it's necessary.. I have a carb engine and it has open vent tubes from the valve covers.

 

[alldodge]

No problem with or without cap on, doesn't matter and is a non-issue

 

[Dave neo]

Ok mine is TBI. There’s a valve cover with a pvc gizmo and I was wondering if vacuum might do something ungood. Thanks for feedback

 

[zellerj]

If you are sticking a skinny tube down the dip stick tube, expect it to take a long time. I found that if you user the male hose adaptor that is on the dip stick tube, it can be done in a matter of a few minutes.

 

[Scott Danforth]

Ok mine is TBI. There’s a valve cover with a pvc gizmo and I was wondering if vacuum might do something ungood. Thanks for feedback

Non issue.

You can't generate enough vacuum at enough volume to ever have it be an issue.

If you had a 300hp diesel powered vacuum pump, the most you would do is collapse the hose

 

[04fxdwgi25]

When there is a PCV in an engine, it has a vent that lets air in from somewhere (usually the air cleaner), otherwise the PCV won't work.

 

[Lou C]

If you are sticking a skinny tube down the dip stick tube, expect it to take a long time. I found that if you user the male hose adaptor that is on the dip stick tube, it can be done in a matter of a few minutes.

Exactly my experience

 

[Grub54891]

I take the hard plastic tubes and set them aside. Go to the local hardware store and get a clear flexible hose that fits the dipstick tube snug. Attach to the pump and tube and pump out the oil. Easy, cleaner and quicker.

 

[alldodge]

OP shouted in first post

using a vacuum pump canister with screw-on connection

no tube down the dipstick

 

[Lou C]

There is no worry about the OP's question, the only vacuum you have to be concerned with is in the oil dipstick tube, you need to have a good gasket on the female fitting and make sure it is tight on the threads of the dipstick tube. I made this up years ago, sucks all the oil out in about 3 min, as long as you warm up the engine first.

 

[tank1949]

using a vacuum pump canister with screw-on connection and with vacuum created wondering if I should loosen the oil fill cap to avoid damage or does that kill the whole idea of vacuum pump? First time using setup - a thanks for any comments

Real pain. Consider purchasing a kit that replaced oil drain plug that has long hose and brass end cap. Mine works great.

 

[Lou C]

If you have a good vac pump and your connection at the female fitting on the hose seals well you can do it that way. Engine had to be warmed up first though.

 

[airshot]

Real pain. Consider purchasing a kit that replaced oil drain plug that has long hose and brass end cap. Mine works great.

Yessir...helped my neighbor install a kit on his, getting the kit on was time consuming and had to be twisted like a pretzel, but once in place.....oil changes were rather quick and simple and drained completely !! Highly recomend them !!

 

[nola mike]

Best thing I did when I replaced my engine. Changing that filter would be a nightmare on this engine

 

[stresspoint]

agreed with all above "" suck away' no damage will be done , be sure to sit boat on flat ground so as all the oil is removed.

 

[rolmops]

I disagree with the idea of not using a plastic tube going through the dipstick tube . Simply because the dipstick tube does not go all the way down to the bottom of the oil pan and you will never get all the oil out without the plastic tube going all the way down to the bottom of that oil pan

 

[Stinnett21]

If you trailer the best way to change oil is with the drain hole hose sticking through the garboard. I do this as soon as possible after leaving the ramp so oil is still hot. I drain straight into my recycle container. Easy and very little mess.

 

[Chris1956]

Gee, I used to drain it into the bilge, and let it flow out the garboard drain into the oil catch pan. It left a little oil residue in the bilge, which cleaned up easily with a few sprays of purple stuff and a blast from the hose. It sure beat having an oily pump and hose laying around......

 

[Lou C]

I disagree with the idea of not using a plastic tube going through the dipstick tube . Simply because the dipstick tube does not go all the way down to the bottom of the oil pan and you will never get all the oil out without the plastic tube going all the way down to the bottom of that oil pan

Actually on OMC/Volvo engines the dipstick tube is attached to the bottom of the pan with a banjo bolt style set up. If you use a garden hose adapter on your oil vacuum pump (female fitting; the dipstick tube had a male fitting) it works much better than the small plastic tube down the dipstick tube. Just make sure the female fitting has a good gasket in it to hold vacuum. I think some but maybe not all Mercruiser engines also have that set up. If not then I agree the rubber hose hooked up to the oil drain plug will work best.