I just picked up a 93 Si hatch , The guy Just put new brake pads on it but the pedal will sink to the floor if I rest my foot on it at a stop, if I pump them up there fine. Im thinking Master Cyl? Does this sound right? It did this before he put the pads on so its been like that for awhile.

 

Definitely master cylinder. The plunger inside the cylinder is allowing fluid to get by instead of holding steady.

 

I was pretty sure this was the only thing it could be, So deff probley the issue then. Thanks

 

also sorry for posting this in the wrong section , this can be closed

 

it happens on EF's too...

its always the master cylinder if theres no change in brake fluid in the reservoir and you can regain brakes after pumping again.

and it typically happens more on a hot day due to expansion.

 

This just happened to me last week! Change the master cylinder and you will be good!