Sealing SU H6

[Richardtr3a]

My float chambers are showing signs of leakage. The holding bolt is tight and I am planning new gaskets with some small quantity of sealer, maybe grease. Has any forum user found a better way to mend small leaks ?

The car is a 1958 TR3A with refurbished SU carbs and the leaks are small but leave a stain on the chamber.

It is better not to have any fuel leaks in the engine bay. ?????

Thanks Richard & B

[BlueTR3A-5EKT]

If the leak is down the side og the float chamber from the joint with the lid it is probably the lid gaskets needing renewing.  If you have done that and they still leak then perhaps the lid or the top edge of the float chamber is distorted and the gasket cannot take up the gap.  Are the lid nuts screwing down enough?  Remove the vent pipe 2 gaskets and reassemble with the vent pipe only between the nut and the chamber lid.  Does the nut tighten enough to grip the lid?  If not that may be the area of problem that the nut is not able to tighten properly onto the lid.

I would prefer not to smother the carb jointing and gasket faces in some sealing compound.  It was not specified nor used originally.  A lot of the jointing compounds are petrol soluble so would wash out when the petrol touches them.  Be wary of using jointing compounds that replace gaskets, as getting the assembled items to bits in the future could cause irritation, and the use of grown up words.

Cheers

Peter W

[MKTR]

Hi Richard - maybe a need to confirm float heights?

Mark

[Andy Moltu]

Very few sealants cope with petrol immersion.

New seals fitted dry should sort it unless it's actually coming out of the overflow in which case it's the chamber overflowing from a sunken float or needle valve not seating (debris or wear) or excess fuel pressure. (Usually this is with electric pumps giving too much pressure without a regulator)