Johnson Lower Unit Drain/Fill O-ring

Salmonseeker

Petty Officer 1st Class
Joined
Jun 11, 2005
Messages
298
Hi Guys,

I noticed in my repair manual they recommend to replace the drain/fill and oil level plug seals every time I replace my oil. DO you guys actually do this every time?

I have never done this in the 3 years I have owned my motor so I thought it might be overdue.

I went to the dealer and picked up the parts. The drain/fill screw has a white nylon washer that is used to seal and the oil level screw has a small O-ring.

The drain washer appears to be correct but have a question about the oil level O-ring. I was given a plane black O-ring that is a slightly different size and completely different colour than the one I removed.

The one I removed is a orange colour and does appear to be squished into flatter shape. Does the colour of the O-ring make a difference? Are the black ones okay to use with lower unit oil? And should the O-ring be flat or was this caused by the pressure the oil level screw had on it and squished it?

I know a lot of questions about a simple O-ring. I just want to be sure, I don't want to waste a second when spring finally arrives.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Johnson Lower Unit Drain/Fill O-ring

they squish, thats, why you change the everytime you remove the plugs. # 1 place for water intrusion.
 

R.Johnson

Rear Admiral
Joined
Sep 24, 2003
Messages
4,446
Re: Johnson Lower Unit Drain/Fill O-ring

Some plug's used O-ring's, others' gaskets', use the correct seal.
 

Salmonseeker

Petty Officer 1st Class
Joined
Jun 11, 2005
Messages
298
Re: Johnson Lower Unit Drain/Fill O-ring

I will definitely replace them.

Does the colour of the O-ring mean anything though?

I am assuming the different colour means a different material. Is a standard black O-ring from a hardware store acceptable to use if it is the exact same size?
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
Re: Johnson Lower Unit Drain/Fill O-ring

I will definitely replace them.

Does the colour of the O-ring mean anything though?

I am assuming the different colour means a different material. Is a standard black O-ring from a hardware store acceptable to use if it is the exact same size?

Color counts. With some effort, I suppose I could look up that orange one is. A more direct answer is yes a hardware stor o-ring is fine IF it is Buna-N (Nitrile). Most are, but it doesn't hurt to check.
 

rjezuit

Chief Petty Officer
Joined
Sep 24, 2007
Messages
418
Re: Johnson Lower Unit Drain/Fill O-ring

Orange is usually silicone. You can use BUNA-N, or Viton they will both work. Stay away from EPDM or neoprene, they cn get degraded by mineral oils. Rick
 

Salmonseeker

Petty Officer 1st Class
Joined
Jun 11, 2005
Messages
298
Re: Johnson Lower Unit Drain/Fill O-ring

Thanks for all the fast replies guys,

I never really thought of all the different materials that a simple O-ring can be made from. I did a quick search and found some charts that show what type of O-ring is compatible with different fluids. Interesting. http://www.allorings.com/compatibility.htm or a simpler version http://aceglass.com/oring.html

The ones at the hardware store were not marked but they do look identical to the ones at the boat shop.
 
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