QuestionI own a 1955 Cadillac Coupe Deville and I am in need of a fuel pump. What do you recommend I get? I'm not sure if I should use an electric fuel pump. I do not have much mechanical knowledge, so I appreciate any help. Thank you.
Jerry
AnswerThe original fuel pump should be replaced if it is failing, because one of the possible failure modes is to allow gasoline to contaminate the engine oil, which is dangerous and also causes rapid wear of the engine bearings. Rebuilt fuel pumps are available from most of the old car parts houses. For example, you can call Egge Parts house at 1 800 866 3443 and order one. They will probably need to charge you a "core deposit" which they will refund when you send them back your old pump. The pump is fairly simple to change, although it is a dirty job, and requires a bit of manual dexterity. Any mechanic who works on your car for you will be quite used to doing this job, however.
An electric pump is sometimes added to an old car, but it is not essential. The reason some add an electric pump to their car is to save wear and tear on the starter motor if the car is sometimes left for weeks or months without being run. When that is done, the gasoline in the carburetor evaporates, and one has to operate the starter motor for quite a while to pump gas all the way from the tank to the engine before it will start. If you've added an electric pump, you can switch it on with a hidden switch to pump up the gasoline before you start it in this situation, thus saving wear and tear on the starter.
Another reason is that in some circumstances, for instance in very hot weather, some cars are beginning to suffer from "vapor lock", because the modern fuels are much more likely to boil than the old fuels these cars were designed for. Modern cars all have electric pumps and other facilities to avoid this, but our old timers just have to suffer with it, unless you have added an electric pump which you can then switch on temporarily if you feel a loss of power when starting out on a very hot day.
If you do have an electric pump added, make sure that it is mounted low and toward the rear of the car, safely out of the way of any road debris, and wired such that it cannot operate if the ignition key is not on. As for plumbing, the two pumps are connected in series - in other words, the fuel line goes from the tank to the electric pump, then from the electric pump outlet to the original pump inlet, then to the gasoline filter, and finally to the carburetor.
I hope this is helpful and clear enough,
Dick
