Soft brake pedal.... at times

[ylwiron]

I could use a little diagnostic help. I have a 94 NSX that at times the brake pedal will slowly drop all the way to the floor. If I "jab" the brake pedal the pedal is solid and the car reacts quickly. If I slowly apply pressure to the pedal, the brakes function properly, but the pedal gradually continues to go all the way to the floor. It is especially apparent at stop lights. This characteristic may occur for 2 or 3 uses of the brake pedal, and then will not recur for a couple of days of driving.

There is no fluid leaking out of the system. If anyone can reccomend some places to look and procedures to diagnose the problem I would be very appreciative.

 

[Briank]

Time for a new master cylinder :smile:

 

[EIFFEL]

Briank is right, This is the classic symptoms of brake master cyl. failing. Esp. more frequent at hot ambient temp.

 

[zomby woof]

exactly. just had mine replaced last week for the same reason.

 

[Sulley]

Sounds just like my '93. Replaced it last week and good as new.
Sulley

 

[ylwiron]

Thanks for the help, I'll get one on order ASAP!

Regards,

Tom

 

[Gearbox]

Might as well replace the slave at the same time.

 

[drew]

Might as well replace the slave at the same time.

That would be for the clutch master sir.

Replacing the 4 calipers (aka brake slaves) would probably be quite unnecessary and quite expensive.

Though I do recommend bleeding out the ALB (ABS).

Make sure you have flare nut wrenches befores you start. This is a mandatory too, unless you want to use vise grips to remove and tighten your brake lines (not recommended).

Drew

 

[ny2ca]

hey guys, this just started happening to me too. Do you recommend I take it to an acura dealership or just a normal brake shop? And how much should this fix cost me?
Any help would be appreciated.

 

[nsxtasy]

Do you recommend I take it to an acura dealership or just a normal brake shop?

Take it to Jerry at Greenlight.

 

[ny2ca]

Before I call, I would like to know an estimate of what you guys have paid for this repair work. Do you have a number for Greenlight?

Thanks

 

[EIFFEL]

Before I call, I would like to know an estimate of what you guys have paid for this repair work. Do you have a number for Greenlight?

Thanks

$315 for part
$150 for labor
$10 Brake fluid
$475 Total + local sales tax.

 

[nsxtasy]

Do you have a number for Greenlight?

It's on their website.

 

[SugrueNSX]

It's an easy DIY
I did mine and I'm an idiot

Regards,

Patrick

 

[ny2ca]

thanks everyone...sorry to be a pain - but I am moving to Long Beach next week - anyone know a good shop up there?

 

[Spudboy]

Probably the master cylinder (mc)... but I also had an exhaust leak once that was heating up my brake fluid, causing the fluid to boil putting air in the lines giving me the same symtoms. I discovered this after changing the mc first only to realize it didn't fix the problem. (At first it seemed like the new mc fixed the problem but once I drove long enough to heat the fluid again the problem returned.)
Look for that and/or bleed your brakes before replacing the mc.

 

[OLDMNSX]

Be sure that they flush the brake fluid when they change the master cylinder. Look at the brake fluid. If it is dark and dirty looking, this is an indication of a master cylinder going bad. It pays to flush the brake fluid every couple years. The brake fluid will get dirty and will also absorb moisture over time from the heating and cooling of the fluid. The moisture and dirt is what causes most of the problems. I have gotten a lot of parts from Mike at Norm Reeves Acura in Temecula, CA 951-491-2440 or 1-888-236-5839, he has saved me a lot of money on parts. Give him a call. If nothing else buy the part from him at a savings and then pay the labor to have it installed. There is really nothing to doing it, if you are mechanical at all and have some tools. If you do it yourself be sure to use a wrench that is made for the nuts on brake lines, they sell them at Sears. You can ruin a brake line by using a plain open end wrench.