brandenc

my 93 teg special editon has a problem where if i press on the brake pedal, i get good pressure for a moment and then the pedal starts to sink to the floor and braking power is gone until the pedal sinks real low and then if I keep pressing on it i can stop the car. If i pump the brakes the pressure builds up more, but will go away sometimes quicker than others, allowing the pedal to sink down again. I have no fluid leaks, I can find no air leaks, and the resivoir is full. I have been reading archived posts, and most similar problems seem to point to the master cylinder, but i have seen at least one post that suggested the booster, and I have a friend who suggest the booster as well. I think it is the master cylinder, but If anyone out there has had a similar problem please let me know what you think, thanks in advance!

zilverz

I would come to a complete stop.... with the same amount of pressure on the brake pedal still being held .. sometimes the car would start to roll forward a little ... my master cylinder was failing internally... new Master Cylinder was not very expensive .. like $150 after installation... fill with fluid ... have friend pump the brakes 4 or 5 times then hold it down to the floor ... you pop the bleeder screw .. and air/fluid will shoot out ... keep doing it on the same side until you get nothing but clear fluid shooting out 3 or 4 times or so .. and you should know for sure you got all the air out of the lines... do that at all 4 points ... put the rims and tires back... brakes should be good as new

dnt94civic

i am having that problem right now. Since you are not sure if it is the MC or BB, I just buy both. most people around here sell both of them together for less than 150. That's what I did.

However, IMO, I think it is the MC.

4doorRS5spd

The master cylinder is your problem, and you probably won't need to get a new brake booster. The brake booster works on a vaccum, and it actually assists in helping you to brake. If your brake booster was failing, it would be hard to push in the brakes, because you would not have that vaccum there to assist. Get a new master cylinder. They're relatively cheap and it is a do it yourself job with the right tools and a buddy.

GSRaCeRbOI

https://honda-tech.com/zerothread?id=209010

I think its the brake master cylinder also... look in my thread (above) it has some prices for your to compare w/... I did this about 2 months ago.. so the prices should be the same/similar... I also had similar problems.. mushy/spongy pedal and if you kept steady pressure it would sink slowly.... changed the MC and everything has been fine for the 2-3 months I've done it...