Help! Does anyone know what is wrong?

[Attitude Adjuster]

Hi everyone,

On the way home from work, I got on my brakes hard to activate the ABS on my 91 NSX. Now, the pump that increases brake pressure comes on every 12-15 seconds for a duration of 20 seconds. Does anyone know what happened or has experienced this? How do I fix this?

TIA,



------------------
Kenji Ligon
91 Red CTSC NSX

 

[Yellow Rose]

The spool valves inside the ABS assembly are stuck because of dirt. The dirt may or may not eventually work itself loose. Until then, the system senses an internal pressure leak from the high side to the low side and is doing what it is designed to do - activate the pump to restore pressure. Other than the pump is running WAY more frequently than normal, there is nothing severely wrong.

If the system does not fix itself, the system will have to be flushed. Just hope the hydraulic doo-dad doesn't have to be replaced, that is an expensive proposition.

 

[Attitude Adjuster]

Originally posted by AndyVecsey:
The spool valves inside the ABS assembly are stuck because of dirt. The dirt may or may not eventually work itself loose. Until then, the system senses an internal pressure leak from the high side to the low side and is doing what it is designed to do - activate the pump to restore pressure. Other than the pump is running WAY more frequently than normal, there is nothing severely wrong.

If the system does not fix itself, the system will have to be flushed. Just hope the hydraulic doo-dad doesn't have to be replaced, that is an expensive proposition.

Good Morning Andy,

Thanks for the reply. Do you know how much it cost to flush the system? About how much does that hydraulic thingy cost? Any ideas?

Thanks Again,

------------------
Kenji Ligon
91 Red CTSC NSX

 

[Yellow Rose]

Although the actual flushing time once the car is on the rack is less than an hour, I wouldn't be surprised if the dealership charges two hours of labor. Including fluid and shop consumables, the total should be around $200.

The last time I checked which was a few years ago, retail price is around $2300.

 

[Larry Bastanza]

Andy,

I think you meant "ABS selinoids". Spool Valves are for the VTEC (I know you know that!!) Anyway most likely a selinoid has gotten stuck from lack of use. First quesiton is simple. Is the ABS light on? If the answer is no the system is working but having a hard time holding pressure.

If the light is on, drive to an area, loose dirt, or wet road, where you can activiate the ABS. Turn the car off and on so the ABS system is Active (no ABS light). Work the brakes hard to get the ABS to engage. Repeat about 5 times.

In most cases the ABS selinoid in quesiton will free up and your problem is solved.

I have had my car 3 years, and this has cured it twice, mine is a 1991, and I do forget to perform this regularly as has been recommended.

Definately try this before the dealer sells you a mucho bucks ABS system.

If this does not cure it, you may have developed a leaky accumulator, or the ABS system has really failed. I think the odds are with you that the above procedure will cure it.

As far as a flush, visit www.danoland.com and see the DIY section to give you an idea about doing the ABS bleed procedure. It is really quite easy. I have the bleeder tool and have made up the switch needed to activate the pump. It is available if you need it. This is an excellent writeup from DanO and I have used it many times.

HTH,
LarryB

 

[Attitude Adjuster]

Originally posted by Larry Bastanza:
Andy,

I think you meant "ABS selinoids". Spool Valves are for the VTEC (I know you know that!!) Anyway most likely a selinoid has gotten stuck from lack of use. First quesiton is simple. Is the ABS light on? If the answer is no the system is working but having a hard time holding pressure.

If the light is on, drive to an area, loose dirt, or wet road, where you can activiate the ABS. Turn the car off and on so the ABS system is Active (no ABS light). Work the brakes hard to get the ABS to engage. Repeat about 5 times.

In most cases the ABS selinoid in quesiton will free up and your problem is solved.

I have had my car 3 years, and this has cured it twice, mine is a 1991, and I do forget to perform this regularly as has been recommended.

Definately try this before the dealer sells you a mucho bucks ABS system.

If this does not cure it, you may have developed a leaky accumulator, or the ABS system has really failed. I think the odds are with you that the above procedure will cure it.

As far as a flush, visit www.danoland.com and see the DIY section to give you an idea about doing the ABS bleed procedure. It is really quite easy. I have the bleeder tool and have made up the switch needed to activate the pump. It is available if you need it. This is an excellent writeup from DanO and I have used it many times.

HTH,
LarryB

Thanks Andy and Larry,

As for my situation, the ABS light doen't come on. I guess that means that the ABS is still working. Can I still benefit from finding loose grave or a wet area to activate the Anti-lock brakes? Or does this mean that the accumulator/something else is bad?

------------------
Kenji Ligon
91 Red CTSC NSX

 

[nsxtasy]

You don't HAVE to find a loose gravel (or grave

) or wet area to activate the ABS. Just get up to medium speed and stomp HARD on the brake pedal and you should be able to activate the ABS on dry pavement.

You have to stomp REALLY HARD on it though...

 

[DanO]

Originally posted by Attitude Adjuster:
...the pump...comes on every 12-15 seconds for a duration of 20 seconds.

Is it still doing this or has it settled down a bit? If it runs for more than 2 minutes at a time then the pump will shut off and the yellow ABS light will indicate on the dash and your ABS system will be disabled.

I recommend a healthy dose of gravel or wet ABS stopping (gravel or wet asphalt with some amount of steering wheel input will help get the rear tires locking too). Just be careful. I’d keep up the activation until the unit starts behaving normally. If the pump keeps coming on and on….this indicates a problem with the unit and will only get worse over time so the system should be checked and fixed by a dealer or tried DIY as Larry suggested: www.danoland.com/nsxgarage/brakes/abs/abs.htm

Good luck and let us know how it turns out,

DanO

 

[Attitude Adjuster]

Originally posted by DanO:
Is it still doing this or has it settled down a bit? If it runs for more than 2 minutes at a time then the pump will shut off and the yellow ABS light will indicate on the dash and your ABS system will be disabled.

I recommend a healthy dose of gravel or wet ABS stopping (gravel or wet asphalt with some amount of steering wheel input will help get the rear tires locking too). Just be careful. I’d keep up the activation until the unit starts behaving normally. If the pump keeps coming on and on….this indicates a problem with the unit and will only get worse over time so the system should be checked and fixed by a dealer or tried DIY as Larry suggested: www.danoland.com/nsxgarage/brakes/abs/abs.htm

Good luck and let us know how it turns out,

DanO

Thanks DanO

I let you know as I'll try it this weekend.

V/R,



------------------
Kenji Ligon
91 Red CTSC NSX

 

[Attitude Adjuster]

Originally posted by Attitude Adjuster:
Hi everyone,

On the way home from work, I got on my brakes hard to activate the ABS on my 91 NSX. Now, the pump that increases brake pressure comes on every 12-15 seconds for a duration of 20 seconds. Does anyone know what happened or has experienced this? How do I fix this?

TIA,

Thanks everyone for your help. I was able to get the ALB to work by taking the car out after a rain and activating the system a few times. The ALB pump doesn't come on anymoer and the system does work when the wwheels lock up.

WHOA!!!




------------------
Kenji Ligon
91 Red CTSC NSX

 

[nsxtasy]