carton30643 Posted November 23, 2011 Report Share Posted November 23, 2011 I have recently with through the whole brake system on my brother's '87 Starion. New brake m/c, new pads all the way around, new fluid through whole system, and new rotors. I've bled the system as the FSM shows and tells. Car still has ABS. The brakes work fine but by fine I mean like a old hot-rod that has manual brakes(the harder the pedal is pressed the harder the braking). The booster isn't making any noise like a vacuum leak and all vacuum lines have also been replaced. I'd like to add the car sat for awhile with no fluid in the system. So what would cause the booster not to work? Thanks a lot in advance!!! Link to comment Share on other sites More sharing options...
Dred_85.5_TSI Posted November 23, 2011 Report Share Posted November 23, 2011 What about the calipers and flexible lines? Did you bench bleed the master cylinder? Link to comment Share on other sites More sharing options...
carton30643 Posted November 23, 2011 Author Report Share Posted November 23, 2011 What about the calipers and flexible lines? Did you bench bleed the master cylinder?Yes all those things were checked and bled correctly. Booster could be bad but just thought I would get some input before tearing it all apart and replacing the booster. Link to comment Share on other sites More sharing options...
Indiana Posted November 23, 2011 Report Share Posted November 23, 2011 (edited) How about the hose to the intake manifold? Is that cracked and leaking? You were able to bleed the front calipers? How about the rear calipers? Did you bleed the ABS modulator? You might want to remove the proportioning valve and clean it, there's a screwed on cap and a spring/piston inside and those fill up with crap and the rear brakes won't do crap and that valve is on the firewall down below the booster near the tranny tunnel. How about the caliper guide pins, did you lube those and they aren't rusty or the boots torn? Does your parking brake cables work? If the cables aren't seized and you pull the handle and the levers on the calipers won't move then the pistons in the rear calipers won't move either when you push the brake pedal because the pistons are seized in the cylinders. Edited November 23, 2011 by Indiana Link to comment Share on other sites More sharing options...
carton30643 Posted November 23, 2011 Author Report Share Posted November 23, 2011 How about the hose to the intake manifold? Is that cracked and leaking? You were able to bleed the front calipers? How about the rear calipers? Did you bleed the ABS modulator? You might want to remove the proportioning valve and clean it, there's a screwed on cap and a spring/piston inside and those fill up with crap and the rear brakes won't do crap and that valve is on the firewall down below the booster near the tranny tunnel. How about the caliper guide pins, did you lube those and they aren't rusty or the boots torn? Does your parking brake cables work? If the cables aren't seized and you pull the handle and the levers on the calipers won't move then the pistons in the rear calipers won't move either when you push the brake pedal because the pistons are seized in the cylinders.All the things you have asked are in good shape and have been checked for use. I'm sure it's just the booster is bad because the car has brakes just not power brakes. Bc we can drive the car and get up to speed and all brakes work fine and stop in a straight line except for the pedal being hard to push thus not having power brakes. Thanks for all the input will swap out with a new booster and will update soon. Thanks again. Link to comment Share on other sites More sharing options...
Indiana Posted November 23, 2011 Report Share Posted November 23, 2011 (edited) Even with a bad booster if the brakes are all working and you mash the pedal to the floor you should at least lock up both fronts and hear the ABS working on the rear. I've never seen one of these boosters go bad. Take the hose off the booster with the engine running and see if you have vacuum there, maybe your check valve(s) have stuck. If the booster is bad, you'll hear a vacuum leak because the vacuum has to go somewhere. Edited November 23, 2011 by Indiana Link to comment Share on other sites More sharing options...
carton30643 Posted November 23, 2011 Author Report Share Posted November 23, 2011 Ok I will try that. Thanks! Link to comment Share on other sites More sharing options...
carton30643 Posted November 24, 2011 Author Report Share Posted November 24, 2011 Update! I feel like an idiot...I pulled the hose off to check for vacuum and I was getting nothing so I traced it back to the nipple on the intake itself...well come to find out the nipple was completely blocked off by rust of some sort. So we took the nipple off and drilled it out and cleaned it up. So now the brakes are fine!!! Thanks for all the help!!! Link to comment Share on other sites More sharing options...
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