my name is josh. i'm a newbie 2 da forum and i seriously need some assistance. i bought a 91 integra gs 4 $1200 back in april from i guy that allegedly "raced" the car. i virtually got it for a steal, becuase it came with a r33 body kit (no bumper), stage 2 clutch (not sure what brand yet), short shifter (not sure what brand), adjustable coilovers (tokico), 17 in. enkei rims, catback exhaust (not sure what brand), and a recent motor swap. (still a B18A1). the only thing truly wrong with it was that the brakes didn't have enough pressure to stop the car on a dime. so far i have changed the brake booster (its a junkyard booster from a 4 dr 91 teg), i've replaced the rear driver side caliper (due to it being frozen), put slotted rotors with ceramic pads on all 4 sides, (summit racing brand), and have bled the lines several times to make sure that there's no air trapped in them. even after this, it still seems to be no pressure building when i pump the pedal. the calipers are functioning, but i have 2 press the brake all the down 2 get them 2 even begin 2 slow the car down. please give any feedback that you may have on the matter. thanks in advance.

 

Possibly a bad master cylinder.

 

how will i be able to tell if its bad?

 

Does the pedal sink to the floor? Can you ever produce pressure when pumping quickly?

 

could be a leaking brake booster

 

That would result in a hard pedal, not a low pedal.

 

possible brake booster leaking....go start the car, and get your head next to the brake pedal and press it with your hand...do you hear a whooshing sound or the engine revving? if so its leaking.

 

Check all your brake lines, and caliper bleeder screws, can also be a bad valve that goes from the booster to the manifold, or a bad prop valve...check everything twice...Also there is a gasket that goes between the booster and the master cylinder that goes bad, check that as well.

 

i put two gaskets between the master cylinder & the booster. when i press the pedal, it feels like its functioning normally, but for some odd reason there seems to be no pressure building when i pump the brakes. the pedal doesn't get harder. its not quite a spongy feeling, just more so.... weak.

 

the only things i haven't changed are the prop valve, the valve that comes from the manifold, & the master cylinder. all of the bleeding screws are good and tight.

 

try replacing the brake master cylinder make sure to bench bleed

 

i did the bench bleed when i put the old master cylinder back on. i may do it again, because i'm not too sure i did it rite after reading a detailed description of it.

 

It's prolly your master cylinder. Same thing happened to me last week and I replaced it. Problem solved.

 

There should be only one gasket between the master cylinder and brake booster. That said I believe you have a leaky master cylinder.

 

now that i think back on it, it may be the master cylinder, because when i was bench bleeding it the brake fluid only came out of the front valve when i fully pressed the piston. it would occasionally shoot from both, but when it did the stream was very weak for the valve in the back. after i let it sit for several minutes, a solid stream shot from both valves after a full press. can this be an indication that its possibly malfunctioning?

 

Well...have you checked the fluid?...sometimes people go way into depth with things thinking there is something a lot worse wrong when it's just a simple problem with a simple solution.

 

the fluid is fresh.

 

Oh ok, well then yeah...most likely the master cylinder.

 

Replace MC, and only use one gasket/seal. I used to have a problem of the pedal sinking to the floor while sitting at a stoplight. New MC fixed that. Then later I had a problem with vacuum in the booster leaking out after shutting the car off. New MC seal fixed that.

Also please type "to" instead of 2 everywhere, it's kind of annoying to read.

 

gotcha. i'm currently saving up in order to replace the master cylinder and possibly the brake booster as well as a set. once i change them, i will notify you all. thanks for the help guys.

 

Look in the area of your barke pedal, if its wet, its bad. I had to replace the clutch mater cylider. It was all wet near the clutch pedal.
But I could be wrong...

 

i actually checked that first, because a friend had the same problem that you had. when i crunk the car up yesterday i had a buddy of mine take the MC cap off and i pressed the pedal down repeatedly. he told me that the fluid in the MC didn't rise or bubble at all as if there was nothing flowing from it, but when i bled the brakes before it seemed to be functioning correctly, because it pumped fluid whenever the brakes were pressed down.

 

I'm changing the master cylinder today (finally had money left over after paying bills). I'll give a report afterwards.

 

I changed the master cylinder and nothing changed. there still seems to be no pressure building up in the systems what so ever.

 

found the problem. turns out that the valve in between the booster and the intake manifold was bad. i got a few of them from the junkyard and tested them until i found one that worked. thanks for the help and feedback as to what might have been the problem.