Hydraulic pump test port threads?

Lesfen · Post by **Lesfen** » Thu May 14, 2009 6:02 am

Would anyone know offhand what the threads are on the Dexta/Super Dexta test port that comes out of the pump housing by the brake pedals?

Thanks,
Les

Post by **Brian** » Thu May 14, 2009 7:48 am

Your easiest test point is on the auxillary service chest where the trailer pipe/loader fits. This is where we always tested from in the dealership.

Lesfen · Post by **Lesfen** » Thu May 14, 2009 3:41 pm

Thanks Brian,
That's really good to know and much handier just to adapt a guage to what I think are pipe threads?

But.. I'm curious as to what the actual threads are on the service plug as well as the threads on the oil filler plugs on the transmission and differential?
They all have a copper ring to seal.
On one of our Super Dextas a return line has been teed in to the filler on the differential using pipe threads but I'm sure that is not really the correct thread.
Thanks again,
Les

Post by **Brian** » Fri May 15, 2009 8:11 am

The threads are either NC or BSP (British Standard Pipe) as far as I remember.

Tubal Cain · Post by **Tubal Cain** » Fri May 15, 2009 1:05 pm

The thread on the auxiliary valve is 1/2" BSP parallel.

The test point plug thread on the pump housing measures 0.555" x 18 tpi and is probably 9/16" UNF.

The filler plugs for the rear axle and gearbox I am almost certain are 1.9/16" UNF! They are definitely not a pipe thread.

As all the above threads are parallel, Dowty seals or copper washers should be used.

Gerald

Lesfen · Post by **Lesfen** » Sat May 16, 2009 5:13 am

Thanks Brian and Gerald,

There are more threads out there than I thought.
Have now found adapters available here to go from BSPP (British Standards Pipe Parallel) to ORB (O-ring boss) or NPTT (National Pipe Thread).

Les