Oil Pressure Gauge - Change to Mechanical Advice, Parts List and Result

[Rich Goddard]

With the electric-to-mechanical oil pressure conversion (Duratec) I’m having trouble replacing the electric oil pressure sender into the oil filter / modine mount, with the steel adapter (to take the hose).

The thread (I think) is supposed to be 1/4” NPT. 

The electric sender (Variohm EPT2100 94245002) seems like a perfect fit (it can be hand-tightened up to about 3-4 threads in then smooth/gradual spanner tighten. 

Whereas the adapter (an MMS 10-3-4, from Think Automotive) cannot be hand tightened in at all, and only embeds about 2 threads in before becoming very tight…so I backed-off with spanner.

At the ‘starting thread’ the outside diameter of the electric sender thread is 13.04mm.

The adapter starts at 13.29mm diameter. 

The thread pitches look identical to me, so I’ve concluded it’s just that small increase in diameter making the adapter an uncomfortably tight fit. 

I’m assuming just 2 threads inserted on the adapter is not enough?

Any suggestions very welcome. Anyone else overcome this? 

Assuming there aren’t different ‘specs’ of 1/4” NPT (?), all I can think of is just trying a different supplier of the adapter at random?

Thanks, Rich 

 

 

 

Edited March 17 by Rich Goddard
Corrected NPT size. Fitting point clarified as Modine mount.

[SM25T]

NPT can be parallel or taper thread. Sounds like you may be screwing male parallel into female taper ?

Edited March 17 by SM25T

[Jonathan Kay]

Is this relevant?

 

Jonathan

Edited: Crossed with previous.

[John Vine]

I think you may have the wrong adaptor.  Those notches suggest a metric thread, whereas (according to Think) the MMS 10-3-4 adaptor is 1/8BSP x 1/4NPTF. 

This was the one I got in the Think kit for my R400D:

 

 

JV

 

 

Edited March 17 by John Vine

[Rich Goddard]

Thanks very much for the replies guys.

I’ll start with trying to determine whether I’ve been sent the wrong adapter. 

[John Vine]

4 hours ago, Rich Goddard said:

I’m assuming just 2 threads inserted on the adapter is not enough?

Correct.  You should aim for 3-6 threads in contact.  Something like this:

JV

[Rich Goddard]

@John Vine looking at your photos I’ve realised I have a different set-up. My car has a Modine oil cooler (I’ve edited my post above), whereas it looks like yours connects directly into the filter housing plate.  Maybe the Modine mount isn’t same thread for the sender port. 

[John Vine]

Yes, my car has an oil cooler in front of the rad,  with a sandwich plate behind the oil filter for the oil hoses.  The MOPG line connects directly to the oil-filter housing.

I know nothing about Modines, I'm afraid.

JV

[Rich Goddard]

Resolved.   Think Auto had sent me the wrong spec adapter first time round.

Don't know what thread it was, but it was very close to the correct 1/4" NPT to fit the sender port in the Modine mount. 

[John Vine]

49 minutes ago, Rich Goddard said:

Resolved.   Think Auto had sent me the wrong spec adapter first time round.

Don't know what thread it was, but it was very close to the correct 1/4" NPT to fit the sender port in the Modine mount. 

Thanks for the feedback.   For general interest, it would be good to know what the thread was.

JV