B7100 oil leak - sealing of oil pressure sending unit threads?

[grossgary]

I have an oil leak that appears to be by the oil light sending unit.

The parts manual does not show any kind of oring or seal there....how is that sensor sealed?

*** Reading/searching the forum - one person mentioned that this engine has an oring that fails in the headgasket right around that area too, anyone comment on that...?

 

[ibnxe]

You will find that the sending unit to block is a tapered pipe thread... most likely 1/8" NPT It is not unusual for these sending units to go bad and start leaking. Clean the area and keep an eye on it to be sure.

 

[Code54]

How do you know if the unit is bad? Is there a way to test them?

 

[ibnxe]

In this case it is bad if it starts leaking oil. Electrically, it is bad if it doesn't have continuity with no pressure, or doesn't open when the oil pressure comes up. It is basically a switch, turning on the warning lamp on the dash.
These units are cheap and available at most any auto parts stores.

 

[j t huskins]

You will find that the sender is a taperd british pipe thread and you will not find one at a basic parts store. This is a good time to install a gauge to monitor your op. The O ring mentioned is just above the sending unit in the head gasket and seals the oil pressure port from the block to the head. Clean the area real good then keep a watch to locate the source. Just remember that the low pressure light does not iluminate until the oil pressure is low . If you fail to see the light in time then the results can be very expensive.

 

[grossgary]

I reinstalled the same sensor with teflon tape on the threads and cleaned the engine up thoroughly. No signs of leakage yet but only an hour or two run time.

The sensor had very old remnants of thread tape from eons ago squished up under the sensor when I removed it. can't decide if that's:

1. a good sign that the stuff was ancient and needed replaced
or
2. a bad sign that someone tried to fix the leak before and didn't get it!

 

[murky]

In my b8200 it is M10x1 taper. You can order the part from several places for about $15 plus shipping.

I went through a bunch of hassle trying to find a T with the right threads to add on a pressure gauge.

 

[grossgary]

I went through a bunch of hassle trying to find a T with the right threads to add on a pressure gauge.

you eventually found a T with that thread or had to get an adapter?

great i have tap, dies, and bolts of that size and bigger and smaller too so i should be able to easily figure it out. i work on Subarus which are all metric, my Kubota oil filter is even the same as one of my Subaru's!

 

[grossgary]

Why not just loose the original oil light? Nice back up to have both I guess...just curious.

So you thread the original sensor into one port of the T adapter.
Then for an aftermarket oil pressure gauge will they fit into an M10 or I need an adapter?

here is an M10 x 1.00 adapter that looks like it would work.
VDO M10x1 Male T Adaptor

here is one that fits into the tractor engine but all the ports are NPT so you'd have to convert the original sensor to NPT:
http://www.ebay.com/itm/LMA-Oil-Pre...W%2BFICS%2BUFI&otn=10&pmod=190636009737&ps=50

 

[murky]

The VDO doesn't fit. It is M10x1 straight and factory is M10x1 taper, at least on the B8200.

I bought an adapter from UK that has male and female to match the tractor and pressure switch plus 1/8 NPT for standard pressure gauges (this is from memory but I can verify).

I think the name of the company is Merlin. It was something like $30 or so shipped and maybe took 10 days. I haven't had a chance to install it yet. Too many projects and the new switch seems to work and light doesn't come on.