Brake accumulator test
#1
Brake accumulator test
Would turbo owners care to do the following in order to tell me if my brake accumulator is shot or not?
Turn ignition to first position
Wait for brake booster to stop running
Pump the pedal and count how many pumps you do before the booster pump restarts.
I only get THREE pumps. I'm sure it used to accumulate more?!
Thanks
Turn ignition to first position
Wait for brake booster to stop running
Pump the pedal and count how many pumps you do before the booster pump restarts.
I only get THREE pumps. I'm sure it used to accumulate more?!
Thanks
#3
Knight, the OP is testing the Brake accumulor not the Clutch Accumulator. The latter is what U think you tested getting 20 pumps before getting stiff. (OMG that just sounds wrong).
What the OP is talking about is the brake accumulator which is in the frunk. I've never tested mine as it is difficult to hear when the motor comes on. Once in awhile if the car hasn't been driven I need to wait a minute for the system to pressurize.
Johnny
What the OP is talking about is the brake accumulator which is in the frunk. I've never tested mine as it is difficult to hear when the motor comes on. Once in awhile if the car hasn't been driven I need to wait a minute for the system to pressurize.
Johnny
#6
Thanks for correcting me Knight. I'll have to experiment with the brake pedal but it's always a bit stiff. I guess it will really stiffen up when there is no accumulator pressure help.
As far as the clutch, my understanding is that failure in the system that backs pentosin back up the reservoir in the frunk is caused by failure of the slave. A leak from the high pressure (power steering pump) to the low pressure (Clutch mechanism) not necessarily in the clutch accumulator. Once again testing the clutch accumulator should result in 20+ presses of the clutch with the engine off until it stiffens up. This could pass fine but still have an issue with pressure leaking to the low pressure side.
Back to regular schedule programming.
Johnny
As far as the clutch, my understanding is that failure in the system that backs pentosin back up the reservoir in the frunk is caused by failure of the slave. A leak from the high pressure (power steering pump) to the low pressure (Clutch mechanism) not necessarily in the clutch accumulator. Once again testing the clutch accumulator should result in 20+ presses of the clutch with the engine off until it stiffens up. This could pass fine but still have an issue with pressure leaking to the low pressure side.
Back to regular schedule programming.
Johnny
#7
I have a new one to swap it out but looks like a PIA job.
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#8
Well, that's my thought. Three pump of the BRAKE pedal and the pump cuts back in for a few seconds. How many do you get between electric pump runs?
#9
Luckily I managed to buy an unused brake accumulator off ebay for £50, not sure on new cost though, maybe 2 or 3 times this.
So I am now faced with replace brake accumulator and also clutch slave as this is now leaking pentosin all over the transmission.....fun time ahead for me.
#11
#12
I believe I only got about 2-3 pumps too. It's basically the only sound you can hear and it comes from the dash. Pump turns on, turns off, car is silent, pump brake 2-3 times, and sound comes back on - cycle continues.
I was detailing my car and had no run the engine at all while doing this test. I'll drive it later tonight. Anything else to look out for regarding this?
O/T - Do the hydraulic clutch and the power steering run on the same circuit?
I was detailing my car and had no run the engine at all while doing this test. I'll drive it later tonight. Anything else to look out for regarding this?
O/T - Do the hydraulic clutch and the power steering run on the same circuit?
#13
I never did this test (brake) however the clutch once I turn the engine off even leaving the IGN ON, the clutch pedal get stiff again quickly if pressed in this situation. As I understand the clutch system is assisted by the pump steering hydraulic that power up the acuumulator of the clutch hydraulic, etc THAT is driven by the engine when (steering pump) is operating and not a electric pump like does the brake vacuum ? If I'm correct, how does work the 3 or more pumps of the clutch pedal test?
#14
I think that it's true the steering pump powers the clutch too but only with engine on.
I guess my brake accumulator is on it's way out after further testing and driving. I think I can hear it running when I'm driving too. Any further info on replacing the brake accumulator would be welcome - parts to replace, cost of parts, hours to replace, cost with labor at a shop, anything else to do while it's getting fixed.
I'll be doing a search now.
I guess my brake accumulator is on it's way out after further testing and driving. I think I can hear it running when I'm driving too. Any further info on replacing the brake accumulator would be welcome - parts to replace, cost of parts, hours to replace, cost with labor at a shop, anything else to do while it's getting fixed.
I'll be doing a search now.
#15
Bump - Any further info on replacement and repair?
My car must have been this way for awhile I guess - is it dangerous to drive like this? Brake warning light coming on after starting for a few seconds was normal I thought but maybe a sign too of brake accumulator failure.
My car must have been this way for awhile I guess - is it dangerous to drive like this? Brake warning light coming on after starting for a few seconds was normal I thought but maybe a sign too of brake accumulator failure.