I have been replacing the brakes on my 87. Did the rear, and lines awhile back and everything went ok. Well I replaced the calipers, lines, etc on the front, and I accidently let the master cyl. go dry. Now I cant seem to get a firm peddle. Is it necessary to bench bleed the master cylinder if it is allowed to go dry? Thanks for your help.

 

If the master cylinder went dry, you probably will have to completely bleed it.

 

By, completely bleed it, do you mean to remove the master cyl. and bench bleed? Thanks

 

That, or use a vacuum bleeder on it.

I use this unit from Harbor Freight myself, but there's others out there: http://www.harborfreight.com/brake-f...der-92924.html

RwP

 

Ok thanks to everyone for your advise. I got it done this morning. I have one of the vacuum bleeders like above, and its always worked well to bleed, but for some reason, I could not pull the air out, which was in the back left wheel.
But FWIW I talked to a mechanic I know, and he said as long as I didn't let it go dry on both cylinders I would not need to pull the master and bench bleed.
What he told me to do, and it worked was, have a helper, (my wife) sit in the truck, for me to start at the RR cylinder, open bleeder, push down brake pedal, close valve, and repeat several times. I did all 4 wheels, but mainly found air in the LR cylinder.
Again, FWIW he told me some are harder then others, said sometimes they use the above method, sometimes they pump it up, and then open the bleeder.