How to change the oil in my Speedaire compressor?

by meg
(Aldergrove, bc)

It's a 20 gallon speedaire model 3Z419J. I've lost the manual.







Bill answers...

Hi Meg:

Every brand of compressor is slightly different, yet all reciprocating type compressors that are oil lubed have commonality.

So, the first question you need to answer is... is your compressor oil lubed for sure?

If you aren't sure, navigate to the Speedaire page on this website, find your local outlet using the guide provided, and ask them.

While you are at it, ask them if they can send you another manual too. :-)

All splash-lubed compressors have an oil sump somewhere under the compressor pump housing. They sometimes have a site glass too, to allow you to see how much oil is in the sump.

Run your compressor without oil and eventually it will seize, just like your car engine would if you ran it without oil.

Some compressors don't have a site glass, unfortunately, though some have a dip-stick built into the oil fill cap instead. Check yours for that as it will make refilling the oil to the correct level much easier.

Look for a plug near the bottom of the compressor pump housing that will thread out. That will be your oil drain. And yes, unless you are really careful, you will drip dirty oil all over everything. So pick your spot, one that won't be damaged by oil leaking onto it if you have a spill.

Drain the oil out into a reservoir that you can use to estimate about how much oil was in your sump. That way you can put the same amount back in, if you don't have a site glass or dip stick to measure the oil level as you refill the sump.

Near the top of the oil sump, usually below the piston housing, there will be a port into which you can add oil. I can't be more specific than that as there are so many brands of compressors, and many have quite different oil-adding ports.

The port into which you add the oil will be vented. That means that there will be a small hole in the cap somewhere to allow atmosphere into the oil sump as the oil is consumed.

Be careful! I'm not talking about the air intake at the top of the pump housing here. Don't put oil into that one.

After you have replaced the plug at the bottom of the sump, add compressor oil (not car oil, not 3 in 1 oil, only compressor oil) into the fill port until you've added about what you've removed. A little more will be OK, but very little more. You don't want to overfill the sump.

If you'd like to see some photos and step by step instructions for checking and adding your oil, pages 49 to 53 of my eBook The Home Compressor offer those. It's now $8.88, and is available right here.

Cheers,

Bill

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Jul 19, 2013
Speedaire Oil Levels
by: Terry

Thanks Bill,

My Speedaire pump itself is a 3Z355J.
the exact oil capacity with the compressor horizontally level is 16 ounces. There is no sight glass and no dip stick but a red sticker on the compressor chassis just below the pump reads:
ADD OIL TO BOTTOM THREAD

The message tag is a tad vague because it might only be obvious to a mechanic that it means fill the crankcase up to the bottom threads of the filler plug hole -- especially since the tag is placed below and between the DRAIN plug and filler plug.

This mode of oil level determination is common to vehicle transmissions and differentials where the placement of the filler hole is placed at the the proper level on the unit. In those cases one fills until the oil begins to flow out.

I just converted to Amsoil 30/40 synthetic.
I used to be an Amsoil dealer.

Maintain your air filtration and extend your ring life, :-)
Terry
_________________
Thanks for an excellent informative post, Terry.

Bill

Jul 18, 2013
Oil Capacity
by: Terry

Bill,

Why not just tell people what the pumps oil capacity is.

I looked at your advice on oil level
where you say to put in the same amount you drain out,
which is a woefully inadequate, un-mechanical bit of advice!
Suppose the previous owner over filled it or the oil was super low. I run into the mistakes of others all the time, especially with carburetors.

You wrote: :
Drain the oil out into a reservoir that you can use to estimate about how much oil was in your sump. That way you can put the same amount back in, if you don't have a site glass or dip stick to measure the oil level as you refill the sump.

After you have replaced the plug at the bottom of the sump, add compressor oil into the fill port until you've added about what you've removed. A little more will be OK, but very little more. You don't want to overfill the sump.
_________________________________

TALK ABOUT VAGUE AND POOR ADVICE!!

Terry
__________________
Deliberately so, Terry. Your points are valid, yet without access to every air compressor model manual, and assuming that the manual actually tells the reader what the oil volume is, there is no way to be anything but vague.

With so many import - cheap - poorly built and woefully supported air compressors on the market, general advice is necessary.

If you have a specific make and model involved, look at the page on that compressor if there is one on this site, and the model specific information could be there. Or, a link to the manual.

If you have a way to provide the oil-level or oil volume information more specifically, I would be pleased to provide that to the readers if you would include it as a comment.

Cheers,

Bill


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SOLO SPEED SHOP

by Bill
(Chatsworth CA)

Wow!
I have had my compressor for over 30 yrs & never drained the tank have never checked the oil & a little plastic washed cracked in the regulator valve & I hope I can get the part! I think one of the best compressors for home use of all times! Bill

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