Okay...so, I had to change a leaking rear wheel cylinder on daughter's Neon. Was wanting to bleed that cylinder while I had the wheel off, but discovered I had no brake fluid onhand. Run to O'reilly Auto and see that all they have is Synthetic Dot3. I'm thinking...I don't recall buying synthetic brake fluid in the past and thought I had heard to never mix synthetic with non-synthetic. Ask the clerk and he says O'reilly corporate pulled all the non-synthetics maybe 9-12 mos ago. He says they are compatible. I'm not sure and figured I'd do some online research (putting brake job on temporary hold). From what I'm reading, Dot3,4 & 5.1 have always been "synthetic"...just never labeled as such on the retail bottles (I know Dot5 is a whole different animal and is silicone-based...and, not compatible with the others). So anyway, what's the deal? Am I having a brain fart...or, has the game changed? Really didn't want to bleed the entire system as it's hard enough to corral someone for even 5 mins. to pump the pedal while I'm manning the bleed screw. Please...not looking for advice in alternate methods to bleed brakes...I've tried them all and am not a fan of anything but old fashioned pedal pumping.