68 GT500 Power Steering?

I had the same trouble and the steering seemed to float around alot as well.

 

It would help to know where it is leaking from. But, here are some things to check;
The resevoir: with some replacement pumps, all you get is the pump, not the reservior. So then you have to takeyour reservior off to install it onto the new pump. Often, the lip of the reservior develops rust. Then the O ring cannot seal. Or, if it comes with a reservior, maybe the place that did the rebiulding did not look close at the lip (on the inside).
And, also, there is a gasket between the reservoir and the pump where the pressure hose adapter screws in.
Make sure the reservior lip is clean and the gasket is there.
On my 67, I found a small gash where the metal hose lip meets the pressure hose fitting. On this I filled the small gash with brazing, then carefully sanded the fitting smooth.

 

I took an easier way with my 67. Converted the power steering
to manual and lowered the upper arm one inch per the Boss 302
chassis manual. My GT500 has a 289 HiPo and HEH-BX 4-speed
instead of the 428. The car runs real well in corners and I have
the road feel you miss with the power steering set up.
However, maybe one day I build it back to a GT500, who knows.
Texas Swede

 

I had one. some people remove them to cure the prblem. I sent everything to Rhode's Restoration in Galion Ohio. he rebuilt the entire system and I reinstalled it. I did not have any leaks and I sold the car before I got it completely adjusted. they all float with the power steering. feel like you are driving a Boat.