A Few More ALB Accumulator Questions

[DrewA]

My ALB pump is cycling running 5 seconds approximately every 25 seconds. No leaks. I have done all the solonoid cleansings (DanO proceedure), clean fluid and stops in the rain to activate the system. I have narrowed it down to the ALB accumulator. Either the accumulator (sphere/bladder) or hight pressure switch.

Q1 It appears from the parts manual that this is sold as a system. That is the pressure switch is attached to the accumulator sphere. This may be on purpose as without a pressure reading/bleeding tool you would not know for sure which was the culprit. Are these sold sperately and where? Larry B has a new accumulator for sale but it may be the switch that is the problem in that it is giving a false signal.

Q2 I do not have access to the T-bleeder. How is the pressure in the system released to replace this part? Would activating the solonoids per the DanO proceedure relaese all the pressure? I believe all the stored volume and pressure in the accumulator would go into the modulator resovoir.

Q3 Once a new accumulator is installed and the ALB resovoir filled with fluid will it replenish/pressurize itself or is some type of bleeding proceedure needed?

Appreciate the help I have received already on this, especially from Drew, LarryB and Ron.

Regards,

Drew Altemara

 

[Briank]

Q1

http://www.nsxprime.com/forums/showpost.php?p=656863&postcount=4

Q2
You can dump the pressure via the solenoids or the bleeder with the T handle or some have had luck getting it loose with a box wrench. Since it is most likely your Accumulator is shot it will not take a lot of venting to remove the pressure. Even just loosening it should do the job.

Q3 yes

 

[DrewA]

Thanks Brian. Can take it from here.

 

[nsxinkl]

I have the same problem too. My nsx will click intermittently for 5 seconds. After flushing the system it would remain quiet for 2 to 3 days and then the noise will return.

Do let us know if changing the accumulator will fix this problem.

 

[DrewA]

I'll let you know. If the system is not leaking and there is no observance of feedback/foam in the ALB modulator resovior I don't see that it could be anything but either a faulty accumulator or incorrectly reading pressure switch. Fortunately I'm replacing them as a unit.

Will let you know.

 

[nsxinkl]

Do you have the part number and how much did the unit cost you?

Thanks

 

[drew]

I have a T-bleeder permanently on loan to the NSX community. You can request it by putting your name on the appropriate DIY forum thread.

If the system is holding pressure, then your pressure switch is probably OK.

After the pump stops running and you stomp on the brakes: does the ABS immediately engage? If so, that would indicate accumulator is holding pressure (and the pressure switch is OK too).

I'm guessing it might not be your accumulator, I suspect the modulator is leaking internally.

What is really neat is that other Acura/Honda's use the same accumulator, pressure switch and pump. You should be able to get those parts for very cheap used. These parts are also available new from any brake house that deals with Nissin parts.

Drew

 

[DrewA]

When the pump stops running and I hit the brakes the car stops normally. If I nail the brakes on wet pavement the ABS will activate normally.

Where could the modulator leak to though? I see no signs of it leaking back to the resovior?

I am going ahead and replacing the accumulator and pressure switch as a first measure and will report back.

Thank you for your help.

 

[nsxinkl]

DrewA,

Did you manage to replace the accumulator and did it solve the problem?

Would appreciate your feedback.

Thank you in advance.

Shaw

 

[DrewA]

I just got done installing the accumulator/pressure switch module.

That was the culprit. Everything working perfectly. No more pump cycling every 25 seconds. ALB working great. No ABL light. Tested it out in the driveway that was covered in pine straw. Seems to have a lot more effective; more pulses but that is hard to quantify.

Install was very easy. The 10mm tube nut attaching to the accumulator was a little tight but a good flair wrench got it.

I realeased the pressure by opening up the solonoid valves and refilled the accumulator by using the DanO proceedure.

Thanks for everyone's help.

Regards,

Drew Altemara

 

[nsxinkl]

DrewA,

Congratulations for fixing the ABS clicking problem.

Did you change the ABS accumulator which you bought from Larry B only?

Does the ABS accumulator module come with the pressure switch or is it sold separately?

Thanks

 

[DrewA]

The Acura part that I bought from Larry B includes the accumulator, bracket and pressure switch. That is the only way to buy it from Acura which was fine by me because the problem could be the accumulator diaphram or pressure switch. Yes, I replaced the entire unit.

I am told the parts are available seperately from Nissan but it made more sense to replace the entire unit.

For me the sign that it was the accumulator /pressure switch was the constant cycling and no discharge back into the the modulator resovoir from the solenoid valves.

Drew Altemara