I have a 1987 Chevy S10 4x4 Blazer with 2 front calipers and 2 back drum brakes. We were working on the front left wheel on a new brake hose and we decided to change the fluid out of the reservoir we drained it to the bottom and put new fluid in. We bleed the front 2 brakes and took it for a ride it's brakes worked fine. Do we have to bleed the two back drum bakes even though we didn't take the fluid out of the lines?
Do I have to bleed the back brakes?
I would for a couple of reasons. First, there is a chance that some air may have gotten into the rear brake lines. Second, the rear lines will have the old fluid left in them. This fluid will most likely have absorbed some moisture and could make your brakes fail if it boils and turns into steam.
It is all about safety, while you may not have to, I think that you would want to, just to be on the safe side.
good luck
Do I have to bleed the back brakes?
you don't have to, but the old fluid is still in the line from the master back.
if the pedal isn't spongy you're probably OK, but you may have gotten air in the lines. If it was my car I would go ahead and bleed the back brakes too.
no, if you didn't mess opening the bleeders in the back you don't have to.
if the front was the only place you were working on then the back don,t need bled, just bleed the front because you have a double master cylinder and air won,t go to the back.
