I had to change both rear calipers.After doing so and spending a lot of time bleeding them I now have very little brakes. the pedal goes to the floor and the light stays on.I get some pedal when I pump it up but it losses pressure the first time I use it.(all fittings are tight and I have no leaks)

 

Jim, go to the BF homepage and in the google search box put in "gravity bleed".

 

Make sure the calipers are on the right sides (bleed screws up) and that the new gaskets are on correctly first,I used a vacuum pump on mine (mitey vac) because the lines had drained while I had the cals off and I didn't want to wait for gravity. Once the cals are partially full of fluid,finish with a traditional pedal bleed.

 

Post #2 in this thread explains the gravity bleed process: https://blazerforum.com/forum/2nd-ge...46/#post559116