940 Fuel Sender Unit

[Forrest]

As others havre said, it’s worth finding out exactly where the leak is. Although the fuel senders are NLA the rubber sealing ring and the large, threaded plastic ring that holds the sender in the tank are both available from Volvo. You should also use a new 6” hose clamp on the outside of the plastic sealing ring to stop it working loose.

If the actual sender is broken and beyond repair then a breaker is your best option. If buying remotely then make sure the replacement isn’t badly corroded or broken itself and has been removed with the electrical cable attached back to the plugs. There is one on eBay at the moment which looks a complete wreck so don’t waste your time with it.

It is worth finding out if you have the older, low-pressure lift pump or the later high-pressure single in-tank pump. It might be possible to convert one to the other but you do not want to inadvertently fit the wrong type. If your car is 1994 or earlier it probably has the two-pump setup. Check for the presence or not of an external (high pressure) pump next to the fuel filter underneath the car.

Whilst a bit of a tricky job, it is possible to get the whole thing clean, secure and leak-free in one hit. The tip to pass on to your mechanic is to soak the threaded ring in hot water before trying to reinstall it. It both expands it and lubricates it enabling you to get it tight enough to make a good seal first time without breaking it.

Good luck.