Topic: 84 Mustang 5.0 GT water pump - HELP!!

[the60sgirl]

HELP please! We have a 1984 5.0 GT and have been told that the water pump we have on it now is the wrong one. Doesn't overheat, but in the morning there is a little puddle of antifreeze underneath it. I've looked up water pumps and have found two that seem to be the right one(s) - BUT - I need to know if this car takes a 6 vane impeller or an 8 vane impeller! I also see that there is either a 3.5" diameter or a 4.4" diameter - how do I find out which one mine is?? Any help would be greatly appreciated - we're trying to get the car ready to go to Carlisle, PA next weekend!! Thanks in advance!!  Alex.

[Jerry Baker]

Hello.   I don't know the answer but I did forward the question out if I get any hits I will post them for you.

[Thierry]

Welcome to the forum the60sgirl.
I made a search and found out that the water pump impeller diameter was increased to 4.4 in. (8 Vane Impeller) to provide better flow capacity for the 85 model year. If your car is stock and a 1984 model you should have the smaller diameter (3.5" and 6 Vane Impeller) pump.
I hope this helps.

[my83horse]

if there is a puddle under the car then you didnt tighten the pump very well.  The only other reason for a leak on the ground is thst the pump is shot and antifreeze will come out of the hole on top,