Brake Issue

[Crawlchevy]

So I am driving down the road in my '95 chevy and the abs light come on and a few second later it goes off. I come to the stop sign and press the brakes, they are still there but not as strong as they normally are. I get off the road and open the hood, resivour is full, no obvious leakes. I have my girlfriend pump the brakes while I watch for spray/leakes, nothing I can see.

Brakes have staid like that all day now, still working but just not as well as they were. Its kinda like I lost pressure. Like air in the system (nothing has been done to it) but even with pumping it does not come back up

Any Ideas of what to look for?

[f250rollinon37s]

have your abs system checked for failure codes by a shop - is it rear abs or 4 wheel ? -

if its 4 wheel it sounds like a pump problem -