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TR3a Fuel Pump Gasket etc…

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Hi folks, I’m brand new to TRs having seen the light and traded my vitesse…….

Can anyone help with the two problems I am tackling with my 1959 TR3A?

Having started with a fuel leak at the pump and the fuel tap, I changed the cork, the pump and the pipe from tap to pump.  The cork from Rimmerbros was useless but I now have some compressed fuel pipe in place of the cork and the fuel has stopped leaking. Pump works fine but the supplied gasket hasn’t done the job. Fairly big oil leak. Should I have used some sealant with it or is it just a bad gasket?

Also, it has a brand new dynalite dynator from powerlite. Appeared to be working fine but now the ignition light comes on after a few minutes. In fairness the battery voltage when not running is only 12.4 which seems low. I know the dynalite doesn’t have an overcharge function so I wonder if the battery is creating the problem…as you can tell, I’m no auto electrician!  I do know the ammeter is past it’s best so any diagnosis with that is unavailable….I do have the trusty multimeter though.

Any suggestions would be appreciated.

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Welcome to the forum 'rookie' - can we have a name to call you by ?  

The ignition light being on means there is less voltage coming from the Dynalite than from the battery. Unfortunately those alternator-in-a-dynamo-case devices tend to suffer failure from overheating because the ventilation is poor, and that may be happening here if it stops working after a short time.   12.4v is a bit low for a battery 'at rest' which may be because it isn't getting charged properly.  Pity your ammeter isn't working as that would show the real story.  With the engine running at a reasonable speed you should measure circa 14.7v on the battery. 

A 'big' oil leak from the pump flange can only be a bad gasket or something not seating properly - is the new pump flange flat and undamaged ?  A gasket fitted dry might perhaps weep slightly but that is all.  

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Horrid job taking the pump off unless you have a selection of small sockets to undo the two nuts.

When you refitted the pump did the 'P' clip that holds the oil pressure pipe get trapped between the block and pump rather than between the pump and retaining nut?  Easy to poke a finger down there to feel

Petrol taps are an ongoing challenge.  This article guides you through some of the issues and the modifications to cure leaks.  Yous rubber pipe trick is an established &  good mod.


Peter W


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Thanks folks, the pump looked fine on fitting and it was a new part. I have just been back out to the garage and checked the oil pressure pipe and it is well clear. I think Rob’s suggestion about the gasket is about right - thanks also for the tips on voltage. I spoke with powerlite before this snag turned up and apparently the fan part of the wheel should be enough to cool it. They suggested that if the battery is a dud, there is no way that the dynalite will get to full steam…not sure if that is a fob off but it is a £400 unit, rather than a cheap import…

I think the pump will be coming off again, which is a shame as I’ve already gone through one set of knuckles! Thanks also for the steer to the fuel tap stuff. A bit of correct gauge fuel pipe is doing much better than the cork but not sure for how long. 



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12 minutes ago, TR rookie said:

They suggested that if the battery is a dud, there is no way that the dynalite will get to full steam

That is definitely a fob-off Jon.   If the dyno output is less than the battery voltage, which is what the light shows,  it isn't the battery at fault. 

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16 hours ago, TR rookie said:

Thanks Rob. They also suggested a lifetime warranty so we’ll have to give that a test.

If they repair it then when you refit it I would fabricate a heat shield for it as even with a standard cast iron manifold they are very susceptible to heat as the casing restricts the air flow, fine for a dynamo but not for an alternator. When you refit the fuel pump make sure you engage the lever correctly on the cam too.


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Stuart. Thanks for the tips regarding the alternator; I charged the battery and then started the car and no red light…if the alternator can’t run everything and charge a battery, probably faulty.

 When I put the fuel pump on last time I felt the lever push against the cam….is it possible to get this in the wrong place?

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