Hydraulic test port kit

[racerboy832]

On both of my mini excavators on the pressure side 90 degree fittings there is a allen plug. On my cheap micrometer it shows the outside diameter of the plug threads is .375 The 1/4-28 thread seems to match the pitch of the plug but not the diameter. 1/8 pipe seems too big. I am trying to come up with an adapter to check pressures. The machine in a Kubota KX 121-2 excavator. Anyone have any adaptor leads?

 

[countrybumpkin]

Could be BSPT 1/8- 28.

 

[oldnslo]

Does this plug have a seal washer or does it look more like a tapered set screw?

If seal washer could be 1/8 BSPP

 

[BHD]

3/8" bolt?

 

[DLTTrekkers]

m8 or m10 ?

 

[racerboy832]

It is a tapered thread with no washer. I am thinking its 1/8-BSPT The manual says 1/8 PT but when i google around, alot of people have run into this trying to put oil pressure gauges on their tractors. The gauges are NPT and the factory Hole is BSPT. All I can find is brass adapters but I am not sure about 3000+ PSI on Brass.