Rear Brake Engagement on a 90

[chevyaddict]

Hi All! Happy Thanksgiving! Hey, quick question. On a 90, are all four calipers supposed to engage under normal braking or only the front? My driver's side rear caliper is engaging (and maybe the other too but I know that side is), even when I barely tap the brake. I know on other chevies the braking is primarily the front and only the rear engages if you depress the pedal more aggressively. How about vettes? My suspicion is I have a "tight" rear caliper and now that I'm doing the back brakes I'm wondering if I should replace the calipers too. Thanks!

 

[vetteoz]

All four work at once.
There is a proportioning valve build into the M/C that regulates front/ rear line pressure plus you have ABS to prevent brake lockup

 

[helphos]

What he said

All four work at once.
There is a proportioning valve build into the M/C that regulates front/ rear line pressure plus you have ABS to prevent brake lockup

All the brakes get some pressure immediately, and it would be equal pressure except for the effect of the proportioning valve. That being said, you may have a sticking caliper or TWO.
I was frustrated when a brake job I did on my son's Saturn gave mediocre improvement. I went back and replaced both front calipers and that did the trick. Both were sticking. It's not always easy to tell.
Good luck!
...and Happy Holidays!