by John L
(NC high country)

recently inherited Sanborn Back Max, 5hp, two stage, 80 gal compressor. Can only read first three and last two of model number –

B51???24, no manuals. Unit is all black in color with large chrome label stating “Sanborn manufacturing Co” and ph# for product asst (not working). Been sitting for about 4 years inside garage. Ready to wire 220v and try to operate but want to change compressor oil. Don’t know how much and what kind to replace it with. Would love to have manuals, but at least help with info about oil capacity and type/grade. Thanks much for any help.

Sanborn black max air compressor - oil capacity and type

Sanborn Back Max air compressor

Oil capacity
by: John L

Thanks much to all for the helpful hints.

Still cant see thru the glass, but can pick out the small bubble in the middle (no color). I’m going to add enough to equal 2qts and fabricate a dip stick to insert thru filler hole to measure to level of bubble, cap it off and keep my fingers crossed.
Feb 02, 2015
Oil viscosity
by: Pete

I recently acquired my fathers Black Max air compressor. It is a 3hp model in like new condition and fortunately the owners manual was in his filing cabinet. The manual doesn’t say the fill volume but it does say to use either SAE 30 or SAE 40 depending on the ambient temperature. I’m going to change the oil with Amsoil air compressor SAE 30/40 and see what happens. I don’t think there is 10 hours time on this compressor but the manual did say to change the oil after the initial 8 hours.

Oil level
by: Jack

The Oil level is to the red dot on the sight glass approx half way up. My Black Max takes around 2 qts when I change it. I use the compressor oil sold at the local auto supply store.
Dec 03, 2014
Sight glass level
by: Bill

Most of the sight glasses we’ve seen for air compressors have a small dot in the center, and the oil typically is added until the oil level is in the center of the dot.

Update on progress
by: Anonymous

Unit is now wired. Decided to go with “compressor oil” from lowes. It is 20w and comes in half qts. Cleaned sight glass best I can but still barely usable. Added quart and half and ran unit for 10 sec, so far so good. Can not see level in glass.
Will fabricate makeshift dip stick and fill to appx half the depth of glass and run again. Anyone have idea how far up the sight glass it should be?

Compressor oil
by: Mark

I have a black max 5hp 60 gallon that is about 15 years old and the compressor uses 30 wt. non detergent oil.

Compressor oil
by: John L

Thanks Doug.
There is no dip stick I can find, but does have a sight glass that appears dingy/dirty. Filler cap is on front right corner, same side as glass. I will try judging amount by the drained amount and hope it is full when I start. Thanks much for your response.

by: Doug in

I believe this is a piston compressor, so you can use either “compressor oil” or maybe 20W non-detergent synthetic.

Don’t know if that has a sight glass or a dip stick, but drain it first to get an idea of the capacity

Have a question about Sanborn Back Max oil capacity, type and grade? Please add your comment here along with photos to help others help you with your compressor and equipment problem!