Triumph Stag User Guide

   Compiled by 

Danimere Bean

To open the bonnet, pull the release handle which is located in the passenger footwell below the dashboard but above the parcel shelf


One of the most important pre-driving checks is the checking of the engine water level.  To do this with an engine that is cold (i.e. not been run since the previous evening) remove the expansion bottle cap by pushing down and twisting anti-clockwise.  The level should be half way up the bottle.  If it is too low, top up as necessary and replace the bottle cap.

Next, check the radiator level by removing the top bung and fill to the top as required

To check the Stag's engine oil level, remove the dipstick which is located on the driver's side of the engine.  In the opening between the cylinder head and exhaust manifold.

The level should be between the two lines on the dipstick.  A helpful note is from minimum to maximum is 500ml

To top the oil up, remove the oil filler cap and top us as required.  We recommend using good quality 20w50 mineral oil

To check the dashpot oil level, remove the dashpot top by unscrewing it.  Top up the level using engine oil until the level reaches the lower parts of the thread (see picture).  Repeat this to the other dashpot.

The brake fluid held in the brake master cylinder.  To check the level, remove the top.  Inside you will see a weir. the level must be slightly above this.  Top up as required with Dot 4 Brake Fluid

The power steering fluid is held in the resevoir located on the front of the engine near the battery.  To check the fluid level, remove the cap.  You will notice the cap is also a dipstick with clear Hot and Cold markings etched on to it.  Top up if required with Automatic Transmission Fluid (Dexron II).

The windscreen washer fluid is held in a bottle attached to a bracket on the turret on the driver's side of the engine bay.  Remove the cap by unscrewing it and fill the bottle with a diluted screen wash mixture.

The clutch fluid is held in a reservoir next to the brake master cylinder.  To check the level, unscrew the cap and inspect the level.  The fluid should be close to the top.  Top up if necessary with Dot 4 Brake Fluid.

If for any reason you plan not to use the car for a reasonable amount of time, you should remove the negative terminal of the battery to stop the possibility of the power being drained.  Using a 14mm spanner, undo the nut a few turns until loose, then wriggle the clamp off the battery terminal and place in front of the battery

To correctly start a Stag from cold you may need to use the choke.  Fully depress the accelerator pedal and hold.  Now pull the choke out fully and rotate 1/4 of a turn.  Release the accelerator pedal.  Now start the engine as per normal.  Once the engine has started you will notice the revs are high.  Twist the choke knob back the opposite way 1/4 of a turn then push in halfway.  Now the engine will be a driveable speed.

If, when you are out driving the car seems to loose power and then finally stops, here are a few helpful pieces to look out for:-

The most common and likely scenario is the engine is not getting fuel, this can be caused mainly be two things.  The first is the fuel inertia switch.  This is located in the engine bay on the passenger's side, in the corner by the windscreen wiper motor.


With the ignition on, pull the top piece up and twist it anti-clockwise, then push and pull it up and down to clean the internal contacts.  If this is at fault, you should now see fuel running through the fuel filter located the other side if the windscreen wiper motor.

The second fault may be with the fuel pump.

To gain access to the pump, open the boot and remove the interior panel on the driver's side.  You now see the pump.  With the ignition turned on and using the wheel brace, tap the pump repeatedly.  The pump should now start ticking which means it is pumping again.

If after a long run you come to a junction and the engine cuts out and will not restart, it is the symptom of a piston sticking up in the top part of the carburettor assembly.

The solution is a simple fix.  Open the bonnet, unscrew each of the tops of the dashpots and push the damper inside down.  You will discover one or both at fault by hearing the piston drop to its seat with a metallic click.

Once you hear this, screw the tops back into place and the engine will restart as normal.