Bentley's repair manual mentions a "sealing washer" that needs to be replaced whenever the oil pressure switch is removed and reinstalled.

I went to realoem.com and looked at the exploded view of the oil filter housing assembly (which includes the oil pressure switch), and it shows no "sealing washer" for the oil pressure switch.

Not only that, but the threads on the switch are 3/8" pipe thread, which generally only requires a fresh bit of plumber's teflon tape and to be tightened to the specified torque to seal.

Is the Bentley manual pulling my leg? I'd like to put my oil pressure gauge sender in place, but don't want to take the oil pressure switch out if there's a "sealing washer" that I need to replace to put it back together....

C ya,
Dutch

 

There will be an o-ring used. My guess is it comes on the new one.

 

That's the rub--there is no new one. I'm removing the oil pressure switch to install a sender for my oil pressure gauge (with the old switch tee'd in to preserve the oil light's function).

The one (seven year old) thread that I found here that details installing an oil pressure gauge (which is for a mechanical gauge, but the parts interfacing the engine block are equivalent) mentions no "sealing washer"--just the customary plumber's tape you'd expect when dealing with pipe threads.

I *think* it's a typo in the Bentley book, but I don't want to go ahead and pull out the switch without knowing for sure, since I don't have another car to go get the "sealing washer", if such a thing exists for this application....

Thanks for your input, though!

C ya,
Dutch

 

You don't want to put plumbers tape on straight threads, which you probably have, if there was a sealing washer under the sender. If it isn't broken, you can re-use the old washer or you can just go to your local auto parts store with the old washer and get one that is the same size.

Dave

 

Dave--
If it's straight threads and a washer, yes, you're right, no plumber's tape. It would be the oddball of oil pressure switches amongst all the cars I've worked on if it had straight threads and a washer, though. All of the others were pipe threads, which take no gasket and use plumber's tape.

RealOEM's diagram shows all the parts involved in the oil pressure switch and oil filter assembly, and it shows no washer on the sender. The Bentley book talks about this washer you have to replace. I'm just trying to find out what to expect before I get it all taken apart. MINI of Tempe is a long walk (at least 9 miles each way), especially when it's 110º out! The local shops seem to have difficulty finding stuff by specs.

I guess, if MINI of Tempe's guy doesn't return my call with a definitive answer, the next step is to call a shop that does both repairs and mods to see if I can find someone who has had the oil pressure switch out, and find out which one's wrong--the RealOEM diagram or the Bentley manual....

Thanks for the info!

C ya,
Dutch

 

Let me know when you’re going to do it and if you need to get another part I'll take you to MINI of Tempe. Just need to know when to make sure I can be available.

Jerry

 

Apply teflon tape and screw it in. That's what I did, and have had no leaky problem.

Jim

 

Thank you!

That's what I figured, but given the "you must replace the 'sealing washer' when reassembling" admonition, I didn't want to take it apart to see if I was right.

Apparently the Bentley manual has a typo....

Awesome! Maybe I can get this thing hooked up on Friday morning!

C ya,
Dutch

 

You are over thinking this, take it apart and see what you have. Manuals always say to replace sealing washers, if you have one, but if your washer looks good, it is good.

You can tell by just looking at the threads if they have a pipe taper, then just use teflon tape.

If you do have a sealing washer, wrapping the straight threads will do no good, it will leak.

Dave

 

I have had mine off a couple times on two different R53s. There is no washer. I used teflon tape on the threads. No leaks.

 

Dave--
You're right, of course. I feel like Norman, the robot in that episode of Star Trek, "I, Mudd", when Harry Mudd tells him "Everything I say is a lie." followed by "I'm lying to you.", setting up a paradox that paralyzes the robot....

Although I've done a lot of work on other cars (and hopped up bicycles and, later, mopeds as a teen), I haven't done much work on *this* car, so I rely on the repair manual for procedures so that I can read through and see if there are any "gotchas" to watch out for, since the Germans have their own unique way of approaching things of a mechanical nature (I grew up around air-cooled VWs) that differs considerably from, say, a mid-'60s Pontiac wagon or Chevy pickup (the other cars I grew up around).

A typo like this can really mess with my gourd....

Thanks!

C ya,
Dutch

 

Jerry--
It looks like the info provided has negated the need for a ride, but thanks for the offer!

C ya,
Dutch

 

Thanks for all the responses!

I got the oil pressure switch out and the hose and tee setup installed to keep the "idiot light" and (finally) add the oil pressure gauge. No runs, drips, or errors.

As it turns out, the Bentley manual has a typo--there is indeed no washer involved in the oil pressure switch, and it's your standard tapered pipe threads deal, like every other car I've ever worked on....

C ya,
Dutch