pressure in accumulator

[s4st04z]

hi ...
How much pressure from break pump ?
I will change new accumulator on break system but i don't have spec for charge nitrogen to accumulator .
somebody know pressure in pump or pressure of nitrogen to charge??
thank you...

[bojangles]

The pressure for the BRAKE (that is a spelling correction!!!) accumulator is written on the label. Take a close look. It is in bar I think so you may need to do a conversion.
There is some discussion about this in the history. maybe just look under my profile. I think there is something there.
Bruce

[fflyingdog]

Its pre-charged so dont try and charge it you will blow yourself up !

[s4st04z]

thank you for correction.
I'm bring the new accumulator from my company .It's don't charge nitrogen.
I saw spec on accumulator. That is maximum pressure on accumulator not pressure from pump(my engineer said).
I will try to find again.thank you

>> Edited by s4st04z on Sunday 12th March 05:03

[bojangles]

I cant remember the label because my car is in winter storage. The Brake fluid pressure must be higher than the empty N2 pressure in the accumulator. I think the accumulator is about half full of brake fluid when fully charged. That means the pressure must be DOUBLE what the empty chage is.
Can anyone tell me (us) what the label says exactly?

Bruce

[s4st04z]

From the manual:
G. PUMP MOTOR OPERATION

1. Turn off the ignition and depressurise the accumulator.
WARNING: Ensure the accumulator is fully depressurised (apply brake pedal hard and release up to 40 times with ignition off) before removing the accumulator.
Remove the accumulator and install pressure gauge TOOOT1112. Install accumulator on the pressure gauge adaptor.

2 . Turn on the ignition and allow the pump to run for at least 20 seconds. Turn off ignition and check for leaks, correcting as necessary. Depressurise the accumulator.

3 . Using the ‘Tech 1’ tool, perform the ‘Total Pump Run Time Test’. Observe the pressure gauge while turning on the ignition. Is there a sudden jump from 0 to 3500 kPa (0 to 500 psi) or more almost immediately after the ignition is turned on? (This initial jump in pressure is the amount of accumulator precharge) If not, and the pump motor is running, perform step 9 of test D ‘Pump Run Time Too Long’. If the jump in pressure is to less than 4150 kPa (600 psi), replace the accumulator.

4 . Note the pressure at which ‘Tech 1’ indicates “OK” pressure. If this pressure is not within the 11,700 to 13,100 kPa (1700 to 1900 psi) range, replace the accumulator pressure switch. Note the pressure at which the pump turns off. If it is not within the 17,900 to 20,000 kPa (2600 to 2900 psi) range, replace the accumulator pressure switch. If the pump continues to run but maintains
a constant pressure, perform step 9 of test D ‘Pump Run Time Too Long’.
NOTE: When depressing the brake pedal to cause the pump to run, press the pedal slowly and carefully until the pump just begins to run. Do not continue to press the pedal after the pump begins to run, or pump run times which are too short may be missed.

5 . When the pump has stopped, press the brake pedal until the pump begins to run. If this pressure is not within the 14,150 to 15,850 kPa (2050 to 2300 psi) range, replace the accumulator.
. . .
6 . If: accumulator pressure switch points are all within range, and; accumulator precharge is greater
than 4150 kPa (600 psi), and; battery voltage is greater than 11.8 volts when the pump is running:
if the total pump run time is greater than 40 seconds, replace the pump and motor assembly.

HTH.

Dr.Hess
I'm copy from Dr.Hess

I will change working pressure to nitrogen pressure .
Somebody please tell me what is working pressure of pump ?
thank you..