1992 Honda Prelude Soft Brake?

Question

I bought a good condition 1992 Honda Prelude 2.3 L auto 2 years ago. I'm very unsatisfy with the brake, because it is soft.

My expectation is that it should perform like brand new car, where a gentle press is sufficient.

Few of my mechanics suggest to rotate/polish the discs, check leaks, brake fluid issue, leak brake hose, bad brake pad. So in 2 years, I done the following, but no improvement

1) Top up brake fluid
2) Replaced all 4 brake pad with sport performance ceramic compound
3) Ensure brake hose no leakage
4) Ensure brake caliper and related parts function
5) Rotate/polish all 4 brake discs
6) Replaced front rotors with sport performance ventilated slot discs

None of these make the brake respond any better. I still have to push the brake hard to react like new car, which only need to press gently.

Front sport slot disc does make front wheel to lock better during hard brake.

Mechanics are thinking I'm asking too much, but I believe they miss something

Rotate the rotor = Turn the rotor

Flushed the brake fluid 2 years ago, when I got the car.

Will try to breed the brake in next few days to share the result

Just bleed the brakes, and replaced the DOT4 fluid. Brake is 50% better, but not as strong as new brake. Any more suggestion?

Answer 1

Have you looked at bleeding the brakes? Your fluid may also be contaminated. I would look at having the fluid in the brake system completely flushed and clean new fluid added. as well as all 4 wheels bleed completely. If this still does not resolve the issue, it's possible you may have a bad power brake booster or poor vacuum to the booster. A properly equipped brake shop should have equipment to test the pressure produced from your brake system. from there they should be able to properly trouble shoot and diagnose the issue. If the shop your going too can not do this or is equipped to do it, take it some where else. most dealers are equipped to do this. Your not asking too much, a certain feel used to be there and if it is not longer there then you do have a problem.

Answer 2

Either you just need to bleed the brakes or the servo has failed.

Rotating? You mean 'turning' the disks? That's just a con, it does absolutely nothing useful, just prematurely wears the disks.

Easy way to test the servo, switch the car off, pump the brakes. If they go solid after a few strokes then chances are the servo was OK and the fluid isn't full of air. If they stay spongy then your lines are full of air. If the pedal is already solid then apply a good amount of force, just normal braking force, then start the car. If the pedal doesn't sink as the vacuum system comes up, which should be inside the first second, then either the brake servo is shot or you have a vacuum leak.

Yes, old car brakes should work just as well as new. Slotted and drilled brakes actually reduce braking effect, you just get less friction surface and less thermal mass, both bad. Especially with those nice ceramic pads, I use EBC Red Stuff myself.

Answer 3

Could be your master cylinder or try bleeding the brakes,sounds like you have air in the lines.