Oil Pressure Switch Socket Size

[mark_53]

I did a search for the OEM oil pressure switch socket size.  Found results indicating 15/16 and 11/16.  Anyone know the correct size?

[Ron Hill]

Mark : Just go to search and type in "Oil Pressure Switch" and you get all kinds of INFO.  I found that it takes  15/16" socket!!

A few thoughts

[Catalina007]

I did a search for the OEM oil pressure switch socket size.  Found results indicating 15/16 and 11/16.  Anyone know the correct size?

Yes but you may not be able to get the socket past the manifold.   Search more and you will find there is a poster here that has a customized cut down socket he will lend you.  `

[mark_53]

I did a search for the OEM oil pressure switch socket size.  Found results indicating 15/16 and 11/16.  Anyone know the correct size?

Yes but you may not be able to get the socket past the manifold.   Search more and you will find there is a poster here that has a customized cut down socket he will lend you.  `

Thanks, I got it out with a 15/16 deep socket.  Looks like a normal 15/16 would work too. Access through the head access door is relatively easy.  I will seal treads with high temp thread sealant.

[KWKloeber]

I did a search for the OEM oil pressure switch socket size.  Found results indicating 15/16 and 11/16.  Anyone know the correct size?

11/16?  15/16?  1-1/16?  26 mm?

Mark

11/16" wouldn't be correct, but 15/16" might not be as well.  Follow me on this.

Matt had an issue (as others have) getting a socket onto the switch -- very long story shortened, his switch was 26mm (very close to 1-1/16".)
https://c34.org/bbs/index.php/topic,9533.msg72047.html#msg72047

15/16" fit Matt's genuine Kb replacement (as Ron noted) BUT it wouldn't be shocking to find out that the Kb switch might actually be metric (24 or 25 mm, very close to 15/16".)

It ALSO wouldn't be shocking if over the decades Kb got switches from different suppliers or the same one supplied switches with different sizes.  Remember in the heyday of the 70s and 80s Universal used whatever parts it could get hold of (different Sherwood pumps, different Oberdorfer pumps) and it wouldn't be surprising if Kb had similar supply issues.  The switch size wouldn't be an issue (and probably not even be noticed on a tractor, etc.) until a large container of coolant is bolted in front of the switch, making it difficult to get a large socket to it.  The switch on Matt's engine was definitely OEM, but was not 15/16".  It was closer to 1-1/16".

NOTE also that Wb's Service Bulletin on the oil switch cautions to "use the correct type socket specifically designed to fit..." (doesn't specify the size.)  What that means is an oil pressure switch socket -- these sockets are most-commonly seen for 1" and 1-1/16" switches. Possibly Wb had seen 1-1/16 (26mm?) switches on some Kb engines (as was on Matt's???)  Just a thought; no supporting data for that hypothesis!

These sockets aren't like a typical 12-pt socket -- they're 6-side and match the shape of the switch (see pic 1.)

Just as an aside it might be that an oil switch socket of the type in pic #2 (this one is a Snap-On 24mm [~15/16] for a Kia/Hyundai) might be easier to get in behind the exhaust manifold?  Just a thought. 
I didn't have that issue and don't know what size was on my '83 M-25 (the switch was located elsewhere so luckily I never needed to shoehorn a socket into that tight space.)

[Ron Hill]

Guys : I don't recall if my 15/16" socket was 6Pt or 12Pt?    I suspect it was 12Pt!!

A thought