TR3A oil pressure gauge/ pipe to block

[TwinCamJohn]

I need to check out the oil pressure gauge for accuracy and I need to screw the pressure checker adapter into the block.

However, I assumed that to release the pipe from the block a spanner would be needed. But, it is round. So it must be undone with molegrips ??

It doesn't seem right so I thought I would ask. Perhaps I am missing something.

[TR graham2]

Oil gallery take off points have UNC bolts with a copper sealing washer 

[Hamish]

On the basis I have my low oil pressure switch is in one of these oil gallery points 

I’m sure you can check the oil pressure via these ports. 

 

Edited April 19 by Hamish

[BlueTR3A-5EKT]

The oil pressure is measured from a banjo fitting that is attached to a stud that holds the oil filter head to the block.   The banjo might be the round bit you have found.   As Hamish has stated use one of the UNC threaded oil gallery plugs to get an oil pressure reading from.

 

Edited April 19 by BlueTR3A-5EKT

[TwinCamJohn]

Ah, I hadn't thought of that !. The front one should be easier to access.

Thanks Hamish. 

I'll report back

[TwinCamJohn]

I have 10 adapters and not one fits. None is UNC.

I can't fit it where the banjo is as it's a stud.

Bugger

[Charlie D]

Could you not connect your "Testing" pressure gauge to the pipe where it screws into the actual TR pressure gauge on the dashboard?

I would guess that that connector  is a "Standard" (?) hydraulic connector.

Charlie

[Lebro]

1/8" BSPP

[Ian Vincent]

On 4/19/2026 at 6:44 PM, TwinCamJohn said:

I have 10 adapters and not one fits. None is UNC.

I can't fit it where the banjo is as it's a stud.

Bugger

FWIW, I had to make my own adapter to connect a pressure gauge into the oil gallery plugs.

Rgds Ian

[BlueTR3A-5EKT]

The stud is where the oil pressure banjo fits.  The oil pressure passes up the outside of the 5/16 stud and into the 3/8 holed banjo, through a 3/8 hole copper washer.  The outer end is sealed with a 5/16 bore copper washer and a capped nut.

[TwinCamJohn]

15 hours ago, Ian Vincent said:

FWIW, I had to make my own adapter to connect a pressure gauge into the oil gallery plugs.

Rgds Ian

In fact a friend has done just that for me. It worked well and shows that my gauge in the car is ok.

Thanks for all your comments.

[TwinCamJohn]

So, as the gauge appears to be ok I am going to investigate the pressure relief valve and the balance valve.

Thinking of getting replacement springs and balls in advance in case they are needed.

But, are the usual suspects trustworthy for those parts ? Any experiences.

[iain]

Not sure what you are trying to check John?

Is the measured oil ressure oscillating with RPM? If so pressure relief valve the ball just needs reseating.

Iain

[TwinCamJohn]

That's the situation. But I wasn't sure what I might find so thought of having the parts to hand if needed.

I don't have any lead linger. In fact I had never heard of it until I looked at the breakdown of parts.

[BlueTR3A-5EKT]

I find it easiest to unscrew only the lock nut and its adjuster housing. Although others remove the entire valve housing, that disturbs the square rubber seal that the housing sits against.
   If there is no oil seepage from the oil pressure adjuster lock nut, you can slack the nut, 1/4 or 1/2 turn, unscrew the adjuster with the lock nut in position.   This is so you have a clue as to how far the thing should be screwed back in.   Pull it and the spring plus the ball out of the housing.  Do not dig the lead seal out that is in the top of the housing.    Clean and renew or replace spring and ball.   The spring usually has a worn and shiny area on one side that may be what is causing the valve to stick.    Screw it back together but wrap a single turn of lead solder wire (coz you don’t not have lead linger) around the adjuster and between the lock nut and the housing.    Set oil pressure (70 psi at 2000 rpm engine at running temperature) and lock the lock-nut as required.   The single wrap of lead solder wire should add to the existing lead seal as the lock-nut is tightened, and stop any oil seepage.   If not.  Let me know as  I have still got a length of Standard Triumph lead linger in the garage.   I would guess you’d probably use a few more wraps of lead solder wire instead though.  The existing lead linger would need removing from the countersunk area where the adjuster screws in if you wanted to do the full job.

[TwinCamJohn]

Thanks, I'll report back.

[iain]

When removing the ball, magnetising a screwdriver is a good way to get it out in situ.

When replacing the ball, a decent tap on it with a suitable drift and hammer will help it reseat properly before zipping the rest of the valve up.

[TwinCamJohn]

I  don't have a spanner that fits the adjuster housing. Any idea of the exact size? There is not a lot of space so it might be easier to take off the filter head and filter housing and work on the bench?

[iain]

I used a Bahco adjustable ( emergencies only 😂), when this happened on a rally starting in Toulouse. It’s never happened before or since!

Edited May 2 by iain

[Ian Vincent]

On 4/30/2026 at 1:10 PM, TwinCamJohn said:

That's the situation. But I wasn't sure what I might find so thought of having the parts to hand if needed.

I don't have any lead linger. In fact I had never heard of it until I looked at the breakdown of parts.

You don’t have to use lead linger. I’ve used a lead washer made out of an offcut of code 4 roofing lead I had left over from a building project. 

Rgds Ian

 

[Ian Vincent]

On 5/2/2026 at 1:14 PM, TwinCamJohn said:

I  don't have a spanner that fits the adjuster housing. Any idea of the exact size? There is not a lot of space so it might be easier to take off the filter head and filter housing and work on the bench?

It’s a 27mm socket for the housing and if I recall correctly it’s a standard plug socket for the adjuster. 

Rgds Ian

[Brianjone5]

On 5/3/2026 at 6:00 PM, Ian Vincent said:

You don’t have to use lead linger. I’ve used a lead washer made out of an offcut of code 4 roofing lead I had left over from a building project. 

Rgds Ian

 

I did the same. Hammered the lead to a thin sheet and then used small/large punches for gasket perforations for bolt/studs to punch out the linger. Linger was a new term to me.