Antilock light question

[Bodhi]

Sympton: antilock light comes on after starting (only when engine is running). It is not dependent on time (as little as 30 sec. and as much as two minutes after starting). I checked the vacuem hose from the throttle body - no problem there. I checked the master cylinder, did not see anything suspicious either. I do not think it is a function of the Ebrake as it is independent of time. I have added brake fluid which was a little low. Good pressure on the pedal, no fading and no pump up. The brakes do not seem to be affected and the car does not pull, dive or pitch. I did not see any such description in the service manuel... Any ideas?

 

[drew]

The brake system is divided into two sections: conventional brake and anti-lock brake (ALB).

You are checking the conventional brake parts, which are probably working well.

Take a look at the modulator, accumulator and pump. The 120 seconds after moving forward is caused by your system "timing out" because it is not seeing enough pressure.

I've opened a Wiki on the ALB for further info.

 

[Bodhi]

I knew someone would be able to point me in he right direction. Thanks Drew! The wealth of information that is available in this forum never ceases to amaze me. Any stock tips? :wink:

Bodhi

 

[Larry Bastanza]

Most likely you have a stuck selonoid in your ABS modulator. You can check to see if your ABS fluid reservoir is wet on the outside(pretty common) If so, you need to "excersize" the ABS.

Go to a dirt parking area. Turn the car off and restart it. BEFORE the ABS light comes on again, get the car rolling and hit the brakes hard and force the ABS to engage. You should feel it in the pedal, it will kick back at you.

Repeat 5 to 10 times. You should end up with working ABS and no ABS light. If this fixes it(has for all the ones I have worked on), get it serviced (flush and bleed) and make sure you use the ABS at least once a month, all will remain functional.

HTH,
LarryB

 

[Bodhi]

Larry,

Thanks so much for the excellent advice. You are a credit to the car and to this forum. I will perform the steps you suggested. I will post my results afterward.

Bodhi

 

[Bodhi]

Larry,

I tried the suggested steps. After 20 locks ups on a dirt road and then 5 on asphalt, I turned the car off. I restarted and tried the brakes again to no avail. I noticed a smal amount of brakes fluid around the fill cap on ABS resevoir. The strange thing is that the first time I hit the brakes, I felt the ABS kick back on the pedal but not after that. Now I'm really confused. Any suggestions?

Bodhi

 

[Larry Bastanza]

Are you getting an ABS light now??

LarryB

 

[Bodhi]

Larry,

The light is still on after a minute or so (no definative time). There is no feedback from the brake pedal and the wheels lock up on dirt and pavement. The cap pulls left in dirt but not so on pavement.

Thanks for your insight on this as it has me baffled.

Bodhi

 

[Larry Bastanza]

OK, When you start the car and it has moved fast enough to get the ABS pump to start, stop, go under the hood and open the reservoir. If it is foaming up in there(assuming the fluid is correctly filled) then you still have a stuck selonoid. You should go to http://www.danoland.com/nsxgarage/index.html and review Dan's write up in freeing the selonoids.

If the reservoir is not foaming you may need a new accumulator, located under the ABS pump. I would then check if there is any fluid leaking around the accumultor ball seal.

HTH,
LarryB

 

[Bodhi]

Thanks Larry,

I printed the link you provided and will follow the directions. I think I will do the entire brake system this weekend as well. I have not bled the brakes in over a year and it will give an excuse to do some detail exam of the rest of the car as well. Thanks again for all the good advice. Too bad I don't live closer to your shop. I could just drop it off, haha:wink:

Bodhi