Missed Oil Change Step?

[2017EX_imp]

At the risk of groans from the readers at another oil change related thread, I wondered if a step had been missed in the various oil change procedure threads, or if it just had not been mentioned because it was considered a "given".

I am of the "old School" group about changing oil hot/warm, for smoother drain flow, suspending particles immediately prior to drain, and the Shop Manual calls for Hot/warm drain. What I noticed is that the various previous threads did not mention the first step in the drain procedure, after the bike is warmed up and shut off, is removing the oil filler cap. This is also the first step in the Shop Manual.

Back in the day, an old time mechanic taught me the finer points of oil changes. Aside from the warm up in order to drain hot/warm oil, he also said to remove the oil filler cap before removing the drain bolt. I asked him why, and he said it eliminated some vacuum in the crankcase so that the drained oil would flow out more smoothly and completely. Same principle as modern gas cans. You can take the cap off the cans pour spout, and gas will pour, but not smoothly. However open the small vent cap on the can first, then take the cap off the pour spout, and the gas will then pour much more freely out of the can.

I thought I would post this small step for those just starting DIY maintenance, as well as those that might not have a Shop Manual. I imagine this will be "old news" and "second nature" to all the other dinosaurs out there like me.

 

[3rdbike_imp]

Exactly!

 

[Arctic cb1100_imp]

crankcases are vented the idea of removing the filler cap first is just an old wives tail!

 

[LongRanger_imp]

Tale.

Certainly can't hurt but it seems to make little difference in flow when I forget to remove it first.

 

[chync_imp]

I’ve never removed the fill cap first. Oil pours out without hesitation.


Sent from my iPhone using Tapatalk

 

[Inhouse Bob]

But it would do no harm. I have found it much easier to get the new oil in if I remove the cap. YRMV.

 

[SportsterDoc]

It is my habit to remove the drain bolt, start the flow, then remove the filler cap. On most vehicles, the flow will increase when the filler cap is removed.
Then I find something else to do and let it drain to the last drop.

If I recall correctly, my Moto Guzzi V7II did not like to drain much until the filler cap was removed and it had two drain bolts for the engine.

 

[2017EX_imp]

I certainly did not intend to imply that leaving the cap on would not work, because yes, the oil will still drain. That said, it has been my experience that removing the cap first does work a bit more efficiently for most of the vehicles I have worked on. When in doubt I defer to the Shop Manual, and in this case, step one is to remove the oil filler cap. Just food for thought, and use the procedure you have the most confidence in.

 

[Django]

It is my habit to remove the drain bolt, start the flow, then remove the filler cap. On most vehicles, the flow will increase when the filler cap is removed.
Then I find something else to do and let it drain to the last drop.

If I recall correctly, my Moto Guzzi V7II did not like to drain much until the filler cap was removed and it had two drain bolts for the engine.

So do I.

 

[peterbaron]

Cap first, drain plug second = common sense with fluids

pb

 

[Magnus_imp]

But it would do no harm. I have found it much easier to get the new oil in if I remove the cap. YRMV.

HAHA... yeah that helps when putting the oil back IN for sure. But remember that the new oil will flow through the motor faster if you leave the drain plug out as well.

 

[the Ferret]

It's funny that this should come up, but Saturday I was up at the shop and asked the head mechanic (30 something years factory trained Honda and Yamaha & the guy that does all my work), his opinion of doing oil changes hot or cold (since I had just changed the oil in my ST Friday and warmed it up with a 40 mile test ride first). He says at the shop, he drains them hot, because it drains quicker, and he is on the clock. At home and on his own bikes (a 2010 Goldwing and a Yamaha XT 500 enduro) he drains them cold, because every bit of the oil and contaminants are in the pan at the bottom of the crankcase. He says it takes longer to drain, but at home he pulls the plug and goes and has lunch and when he gets back, it's drained. He felt he got out more contaminants that way.

 

[Tezza_imp]

Pity that the oil flows out of the engine a lot faster than it goes in. Why did Honda make such a tiny hole for the filler plug?

 

[peterbaron]

General rule/theory;
As the oil pan is mostly flat at its bottom, oil, dirt, metal filing drain out better and faster due to thin oil.
If cold/thick oil, some of above particles may stay trapped with oil on flat (no flow) oil pan surface.
The best: drain it hot, leave it for some time or overnight, then install back drain plug/washer.
You will drain a bit more oil when hot, not cold.

:worship:

pb

 

[Jim21680_imp]

Remember, we're talking about a bike that leaves at least a quart in there, no matter how many tiny drops you let fall out of the pan, hot or cold, long or short.

IT DOESN'T MATTER.
Now, having said that.....I'm the guy who, during my last oil change, was bored enough to actually unbolt the oil cooler and associated lines, and drain them too.

I'm still not sure what possessed me to do that, but like I said, it was a rainy day and I was seriously bored.

Conclusion? It was a big mess, I'm an idiot, and the extra few ounces of oil I got out was just absolutely not necessary.

Plus, the risk of stripping one of the bolts going into the block wasn't just unnecessary, but downright foolish.

 

[peterbaron]

Remember, we're talking about a bike that leaves at least a quart in there, no matter how many tiny drops you let fall out of the pan, hot or cold, long or short.

IT DOESN'T MATTER.
Now, having said that.....I'm the guy who, during my last oil change, was bored enough to actually unbolt the oil cooler and associated lines, and drain them too.

I'm still not sure what possessed me to do that, but like I said, it was a rainy day and I was seriously bored.

Conclusion? It was a big mess, I'm an idiot, and the extra few ounces of oil I got out was just absolutely not necessary.

Plus, the risk of stripping one of the bolts going into the block wasn't just unnecessary, but downright foolish.

U did it = you learnt a hard lesson = is the best way to remember own "mistakes"...from now on u can only be better:clap:
Good luck next time
:beerchug:

pb

 

[Lord Popgun]

Jim, Just how much oil was left in the oil cooler? Rough guess is good.

 

[Jim21680_imp]

Maybe 10-15 ounces? The oil cooler itself is easy to remove and drain, even if it does make a bit of a mess. It's the lines that I shouldn't have touched.

 

[Lord Popgun]

Thanks Jim. I’ve been wondering for some time.

 

[pdedse]

I used to get together couple times a year with KLR650 owners for "tech days". Regarding oil changes, a guy suggested, that once "all" the oil had drained, leaning the bike over to one side for 15-20 seconds, then the other way for another 15 seconds...sure enough, another stream of oil would begin to flow somtimes lasting more than 10 seconds. I can do this on my KLR about 5 or 6 times, each time more oil comes out. I tried the same on the CB1100 this evening and sure enough, after leaning the bike this and that way, a bunch more oil drained (had to put plug back in and move oil pan to the side so it wasn't in the way as I took bike off center stand to lean left/right). Tried it again, and not nearly as much as the first time, but some. That was good enough as the CB is heavier than the KLR650 by about 130lbs.