Oil pressure switch

Is it possible to clean an oil pressure switch? Mine is bad, and I wondered if I took it out I could clean it, or is it sealed and I have to buy another one. This is on an R80ST. I know it is the switch, cause if I ground the wire from the switch to the case, the oil light comes on, and I dont get continuity to ground from the spade connector from the switch.

lorazepam said:

Is it possible to clean an oil pressure switch? Mine is bad, and I wondered if I took it out I could clean it, or is it sealed and I have to buy another one. This is on an R80ST. I know it is the switch, cause if I ground the wire from the switch to the case, the oil light comes on, and I dont get continuity to ground from the spade connector from the switch.

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Take it to a discount cage bits place and get a new one (without the roundel on it) with matching threads for about US$3. The thing is supposed to make the light turn off at about 2PSI.

hey thanks Flash, beats spending 5 times that amount for a gen u wine BMW part. Will I lose much oil when I remove it? I wouldnt think so, it sits pretty high up on the block it seems

lorazepam said:

Will I lose much oil when I remove it?

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Nah, just two or three drops.

Thanks Flash

Since you are on a roll dispensing your wisdom this evening, the dang neutral light is real erratic, but seems to work better when the bike is moving.

the schematic shows a normally open circuit, that closes when neutral is engaged.
Is this something to hold off on until a major job comes up, or can I check this switch without removing the tranny. the manual isnt very clear about this.
I am also working in an unheated garage, and Dont really want to tear this thng down till it gets a bit warmer.

lorazepam said:

Since you are on a roll dispensing your wisdom this evening, the dang neutral light is real erratic, but seems to work better when the bike is moving. the schematic shows a normally open circuit, that closes when neutral is engaged. Is this something to hold off on until a major job comes up, or can I check this switch without removing the tranny. the manual isnt very clear about this. I am also working in an unheated garage, and Dont really want to tear this thng down till it gets a bit warmer.

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Assuming it is a 5-speed, the odds are that the switch is bad. Though you might remove the light bub and clean the contacts and socket and see if that helps before you mess with the switch.

To replace the switch:
Remove however much exhaust system you have to in order to remove the muffler under the trans. Drain the trans. Put a jack under the rear of the motor and raise it until it JUST takes the load. Pull the rear motor mount bolt all the way out. Take a BIG screw driver and pry the aluminum tube out of position, it is the spacer through which the motor mount bolt goes. Replace the switch. DO NOT OVERTIGHTEN. Those things are easy to make leak if you get ham fisted. Be SURE that you removed the original crush washer before you install the new switch and washer. Take a file to the big spacer and put a SLIGHT chamfer on one half of each end. This will make it lots easier to pound into place. Reassemble in reverse order.

Thanks again Flash

Well it isnt as bad as I thought it would be, but still sounds like lots of fun. I have checked the bulb and I am going to make sure the connectors are all cleaned up at the switch.
These old airheads are fun to work on and arent nearly as bad and the oilheads.

Is it possible to clean an oil pressure switch? Mine is bad, and I wondered if I took

Buy a new one. Mine was $8 from Capital....

Gmac

Yeh, just buy a new one, auto replacement or BMW. The long socket needed to replace it will cost more than the switch.

To replace the oil pressure switch, you'll need a long socket of the correct size. If you're really lucky, you might have a thin-wall cheapo socket in your tool kit that will fit.

With that new socket, you need to grind off an arc around a portion of the outside to clear the bulge in the engine case. Assuming you've remembered to shut off the engine, there won't be any oil squirting out of the gallery when you remove the switch. Clean the surface, and screw in the new switch with a fresh crush washer.

So, an hour to buy the switch, another hour to find a long socket, 15 minutes to grind off the socket to clear the case, and 1 minute to swap the switch.

Flash is spot on with his explanation of the neutral switch. You can reach that one with an open end wrench after popping out the spacer. It's easier with the rear wheel removed. While you're checking out the switches, unscrew that bolt on the lower left of the transmission--the one with a little brass connector and a single wire. Clean it shiny, scrape the surface of the case clean, grease everything with Vaseline, and reconnect.

pmdave

With that new socket, you need to grind off an arc around a portion of the outside to clear the bulge in the engine case.

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Ummm, what engine is that? I found that on my '95 R100 a plain old wrench did the trick, no grinding or any weirdness with being able to reach the switch.

Update

I had to get the switch from the dealer, since no one at the cage parts stores had one with the same threads. I guess I live right, cause I was able to remove the old one with a standard depth socket, (just couldnt bottom out the extension in the socket due to the connector) It also kept me from over tightening the new switch when I reinstalled it.

Once underway, the neutral switch works fine, and I will tackle replacing it once the weather warms up. Laying on a concrete floor in 20 degree weather is not my idea of fun. It is good to see that BMW has a history of putting stuff in the way of other things you need to fix, and not just on the oilheads.

My R80RT had a leaky oil pressure switch the day it was delivered new.My R100 PD leaked at 5K,and I saw an R100R with a blown engine when the rider didn't notice his leaking switch.Lesson? Carry a spare,check it often!

lorazepam said:

snip
Once underway, the neutral switch works fine, and I will tackle replacing it once the weather warms up. Laying on a concrete floor in 20 degree weather is not my idea of fun. It is good to see that BMW has a history of putting stuff in the way of other things you need to fix, and not just on the oilheads.

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It's just me but...this is the kind of thing I would put on the list of things to do next time I wanted to lube the clutch splines and hit it while the tranny is out.

Steve

whicks said:

I saw an R100R with a blown engine when the rider didn't notice his leaking switch.Lesson? Carry a spare,check it often!

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Hunh?

Can you explain how a failed oil pressure switch "blew up the engine" without turning on the oil light first?

Carry a spare? I've never heard of one failing catastrophically. In over 200k miles on airheads, I think I replaced all of two oil pressure switches, cuz they were leaking and the bike was "marking it's spot," like a Hardly Davidstone.

I had no problems using a deep-well socket to remove/replace the oil pressure switch.

For the neutral switch...

Rather than prying out the spacer, just tap it forwards. Do it carefully, keeping it nice and even. Once it clears the frame, you can easily grab it and pull it out. I removed the whole back half of the exhaust to make the job a LOT easier.

To reinstall it, grind the edges just a bit to round 'em. Put the spacer in the freezer for a few hours, then tap it carefully in place. Start low as you can always tap it a bit upwards if need be, but can't the other way round.