oil pressure sensor removal to repair oil leak

[roy826]

I searched the subject and not much of anything on it. The Sensor is plastic, 40 year old plastic. I have ordered a new Suzuki oring. Question is, what am I looking at on this? any tips or not to dos. I know to unplug it then unscrew the plastic sensor and I assume the oring is attached to the sensor and just add the new one and reverse reassembly. Just don't over tighten it being the part is 40 years old and plastic. Not planning on pulling the carbs to do this. I have small hands and can easily access from clutch side of bike. The only leak is at the base of the plastic sensor itself and not leaking at the metal base plate cover the sensor screws into. Or does the base plate have to come off first then remove pressure sensor? No shop manual on hand.

1982 GS1000S Katana is the bike, thanks

 

[bwringer]

It's entirely straightforward. Remove two bolts, and there's a funny-shaped o-ring sealing the body of the sensor, and a round o-ring sealing the plastic switch "nut" on top. Make sure you have both o-rings if you remove the whole thing. All that said, if you unscrew the plastic bit, there is a non-zero chance of breaking it. Plastic gets brittle with age and heat, so no guarantees.

You can just remove the plastic "nut" if you feel an urgent need to do so and the risk seems worthwhile. It's quite simple, just a contact and spring; no deep magicks in there.


So that leads me to ask: are you SURE that's actually what's leaking? It usually isn't.

Oil on this switch is more commonly a leak coming from the seal in the cam chain tensioner just above. Here are my instructions for rebuilding this:
https://www.bwringer.com/gs/camchaintens.html

The tensioner on your bike will look a little different, but it works the same. And they ALL leak after 20-30 years.

If you've already rebuilt your tensioner and you're sure it's not leaking, then never mind...

 

[roy826]

It's entirely straightforward. Remove two bolts, and there's a funny-shaped o-ring sealing the body of the sensor, and a round o-ring sealing the plastic switch "nut" on top. Make sure you have both o-rings if you remove the whole thing. All that said, if you unscrew the plastic bit, there is a non-zero chance of breaking it. Plastic gets brittle with age and heat, so no guarantees.

You can just remove the plastic "nut" if you feel an urgent need to do so and the risk seems worthwhile. It's quite simple, just a contact and spring; no deep magicks in there.


So that leads me to ask: are you SURE that's actually what's leaking? It usually isn't.

Oil on this switch is more commonly a leak coming from the seal in the cam chain tensioner just above. Here are my instructions for rebuilding this:
https://www.bwringer.com/gs/camchaintens.html

The tensioner on your bike will look a little different, but it works the same. And they ALL leak after 20-30 years.

If you've already rebuilt your tensioner and you're sure it's not leaking, then never mind...

It is definitely leaking at the base of the plastic sensor itself. I can see it build up oil there with it idling and wipe it off and it comes right back only at the base of the plastic sensor where it joins the lower aluminum piece. Cam chain tensioner above all that is totally dry.

 

[bwringer]

It is definitely leaking at the base of the plastic sensor itself. I can see it build up oil there with it idling and wipe it off and it comes right back only at the base of the plastic sensor where it joins the lower aluminum piece. Cam chain tensioner above all that is totally dry.

Sounds like you've got it pinpointed!

If I were you, I would also be ready for the possibility that plastic nut whatsit is already cracked or damaged, or will crumble when you remove it. It looks like it's still available from Suzuki for about $20, and the same part was used on a skrillion other GS models, so getting another shouldn't be hard at all.

Or, it might spin right off and the new o-ring will fix ya right up... hard to tell from here!

 

[roy826]

I plan to heat up the engine some running before attempting to remove the plastic sensor. hopefully it won't break but if it does I'll just order a new one and wait for it.

 

[roy826]

All is well with the oring replacement. Sensor came out really easy. No drama. Oring was flat in it and hard as a rock. New one on and no leaky. It was barely tight to begin with the old hard oring. I put it in hand tight and 1/4 turn on the new oring. It’s fixed. Also replaced the oring on the tach block off plug on valve cover. Same thing it was hard as a rock.

 

[rphillips]

Yep, sounds like 40 yr. old "O" rings, flat hard as a rock. Glad all went well.

 

[bwringer]

Excellent! Thanks for reporting back!