Help with brakes(!)

[Dr Fildo]

So I have recently replaced all 4 rotors, new pads all around, and bled all 4 calipers. My brake pedal is soft, and I failed NJ state inspection for rear brakes after all this work. I know the rear brakes are working, b/c the rotors are shiny where the pads are doing their job. Why is the pedal so soft, and what gives with the rear brakes? Oh, I also put in a new master cylinder last summer b/c the pedal felt soft, but it didn't change anything. Are the rear calipers bad? Do I need a new vacuum booster? I do not have testing equipment for that, and do not want to throw a lot of cash at this problem if I can help it. No codes with computer test.

HELP!!!

 

[Codycougar91]

they didnt tell you why they failed your rear brakes?

 

[sbr420a]

do you have a v6 or v8? if it is a v6 i think they come with drums so it could be a wheel cylinder, or if it is a v8 it may be a crappy master cylinder

 

[GDTrumbo]

All '94+ have 4 whl. disc.

Sounds like air still in the lines. Was the MC bench bled before the install? Then the complete system bled?

GT

 

[sbr420a]

with draw my drum statement i just read it again and you said 4 rotors

 

[Dr Fildo]

It's a V8. Already replaced master cyllinder. They gave me a print-out with a diagram that shows that the driver's rear is grabbing like 10% and the passenger rear is like nothing at all. The fronts are doing great. Grabbing 100%.

No, did not bench bleed the MC, but the brakes were soft before the change of the MC.

 

[GDTrumbo]

With one rear grabbing 10% and the other 0, sounds like the rear calipers are either not floating on the pins correctly or the caliper's pistons are seized up. The pedal should feel hard rather than soft. Kinda strange....

GT

 

[Dr Fildo]

I greased the pins well when I changed the pads and rotors. I also rotated the piston when pushing it back in. I was VERY difficult at first, but by the time I got them all the way in, they were moving smoothly. They seemed to be alright (the calipers) when I re-installed them. But I'm not a mechanic (and it shows, by the crappy performance of the brakes immediately following my work). Maybe I'll bleed them again.

 

[GDTrumbo]

Now , there is a certain sequence or order that the calipers are to be bled in. RR, LR, RF and lastly the LF. Rule of thumb is do the farthest corner from the MC first and work your way to the closest, constantly checking the MC fluid level.

Your rear calipers could still stick at some point shy of their full travel. The calipers are not too expensive to replace.

GT

 

[Dr Fildo]

I did not know that. I'm sure I did it bass ackwards. If I have to replace them, where's the best place?

 

[atlanticblue98]

do you have a v6 or v8? if it is a v6 i think they come with drums so it could be a wheel cylinder, or if it is a v8 it may be a crappy master cylinder

V6's have 4 wheel disc brakes

 

[sbr420a]

thought some had drums. oh well

 

[riored96gt]

All '94+ have 4 whl. disc.

Sounds like air still in the lines. Was the MC bench bled before the install? Then the complete system bled?

GT

I was just thinking the same thing...

 

[riored96gt]

I did not know that. I'm sure I did it bass ackwards. If I have to replace them, where's the best place?

$35 last year at Advance

 

[GDTrumbo]

I did not know that. I'm sure I did it bass ackwards. If I have to replace them, where's the best place?

You need a Haynes or Chiltons service manual for that car. Worth it's weight in gold.

GT

 

[Dr Fildo]

I have the Haynes manual, and it is a HUGE money/time saver. Anyway, I re-bled the rear calipers and finally passed inspection, although I have to say that I don't see a huge difference in the way the pedal feels or the way the car stops.

 

[GDTrumbo]

You bled only the rears? Another thing when bleeding, avoid the classic "pumping" of the pedal. Contrary to popular belief, this does not help. Gravity bleeding works well too.

GT

 

[riored96gt]

You bled only the rears? Another thing when bleeding, avoid the classic "pumping" of the pedal. Contrary to popular belief, this does not help. Gravity bleeding works well too.

GT

Speed Bleeders FTW! I have them on my 3/4 Ton Chevy now too.