Tuesday, March 06, 2007 - 02:25 pm, by: Dave Hart(Davyboy)
This is the motor with the pump on the end. You'll need to pull the whole ABS/TRC unit out as this is slung underneath. One of the problems is that brake fluid leaks back along the motor/pump shaft and gets mixed up with the dust off the carbon brushes. The stator cover will come off the motor and it can be cleaned up and the commutator skimmed. All this may not be enough if the motor is genuinely rooted in which case you can buy the whole ABS/TRC accumulator and master cylinder unit for about $3k. If you can find a s/hand unit it might be ok for a while or it might not because they'll be about the same age.
Friday, March 16, 2007 - 10:39 am, by: Tom Richards(Tomr)
hi dave
thks for the help. what does the pump actually do.
i only have the error code some of the time. everthing seems the operate the same, error code or no error code. I havent checked if traction control works when the error code is on.
Am i correct in thinking that the pump is a part of the traction control (not abs).
do you know the connections to the pump. What wires are the "sensor" wires that trigger the error. My thoughts are if the pump is traction control only, and you are happy to live without traction control, you can "disable" the sense wires and have not error message displayed.
Friday, March 16, 2007 - 05:21 pm, by: Paul Drane(Paulwd)
I was getting brake system warnings a while ago, replaced the accumulator, problem fixed. Then about six months later, brake system warnings, ABS warnings, TRC light flashing, I think the codes were 41 and 53, couldn't be bothered stuffing around finding out what was causing the faults, so I replaced the whole master cyl assembly, no more fault codes.
Tuesday, March 20, 2007 - 04:38 pm, by: Dave Hart(Davyboy)
Tom, the pump keeps the available brake fluid pressure up to a certain pressure by filling the accumulator which has a nitrogen cap. Over time that nitrogen pressure will leak away and the pump will need to pump more often until it runs nearly continuously and it can't keep up. The thing is to replace the accumulator before the pump gets rooted. Think of it as a tyre and it gets a leak so you blow it up. If the leak is very small you only need to inflate it now and again but as the leak gets bigger and bigger you wont be able to inflate it fast enough. Paul did the sensible thing and replaced the lot. Costly I know.
Wednesday, March 21, 2007 - 09:27 am, by: Tom Richards(Tomr)
dave I have followed with interest a lot of talk re the accumulator being regassed with nitrogen and the problems of not knowing the correct pressure etc. The accumulator is a sealed unit, why is nitrogen used? is it because it is inert and more stable to temp change than air?
I have wondered why an air valve hasnt been fitted, and pressure progressiveley increased until correct operation occurs.
Back to the problem of the leaky accumulator, is only TRC affected by the acc/pump being stuffed.
Wednesday, March 21, 2007 - 02:36 pm, by: Dave Hart(Davyboy)
Tom, there's not much metal thickness on the accumulator to fit a valve. The screw at the top is quite small in diameter and length so any valve would need to be small. In saying that I don't think it would be too difficult and as the unit unscrews it could have the o-rings replaced and go back good as new. ABS is affected and any ABS fault will knock out the TRC as well. When mine finally gave up I lost all brake assist so had to limp home at slow speed in order to stop the car with just foot pressure.
Dan McColl Goo Roo Victoria Active V8 and a Factory Manual XF.
Sunday, March 25, 2007 - 03:40 pm, by: Tom Richards(Tomr)
my car is a V8 without TRC, but my sons has TRC.
In the car with TRC, he gets the error 51 code. the error code in itself is the ennoying thing, not the lack of TRC, as the conditions and how the car is driven mean TRC is never operated even when it is working.
Driving the car with no TRC (as mine is) is not the problem, it is the error message that drives you mad. My understanding f the accumulator was it was pressurized to enable the TRC to apply braking to the rear wheels in the event of loss of traction. With this the faukt in the car, turning off TRC does not get rid of the error message. On start up, the pump runs for ~ 10 secs then stops, but the error message is still there.
The car drives and brakes with normal foot pressure on the brake, but the error message is still there. Rather than spend $3k to fix the error message, we would be happy to drive the car as mine is without TRC, and not have the error message displayed. The error message must be generated from a sensor of some sort. The brakes work great with normal pressure, only the TRC function is not working. I would have thought it is possible to "stop" the error message and drive the car without TRC, as it is currently being driven.
Dan McColl Goo Roo Victoria Active V8 and a Factory Manual XF.
Sunday, March 25, 2007 - 07:32 pm, by: Dan McColl(Hoon)
But yours has a vacumn booster. The cars with TRC use the pressurised brake fluid as the booster.
To remove the trc, you would need to remove the entire assy, and replace it with a assy from a non TRC car, including the booster. Then you would also have to fit the non TRC ABS unit and get that working as well.
I'm sure there would also be 1 or 2 ecu changes in there as well.
Probably cost as much as just fixing the TRC properly.
Friday, March 30, 2007 - 03:14 pm, by: Tom Richards(Tomr)
hi guys.
taking a step back, a lot of owners fix the brake fluid level error message by unplugging the faulty sensorand checking the level visibly.
I am trying to do something similar with this error message 51.
The symptoms i have are:
1)error message is only present some of the time. Brakes are the same with or without the error message. 2)the acc pump only comes on for ~10 secs on start up. It is the same with or without the error message. 3)there are no brake fluid leaks 4) error message sometimes comes on with the self check immediatly after start up and at other times when driving.
Because of the random nature of the error message coming on and at all times the feel of the brakes being the same, my thoughts are that it is a faulty sensor or connection (ie the fault is electrical not mechanical, and does not indicate a real failure in the system)
does anyone have a cct or know what are the sensor wires and locations that are able to trigger error code 51. If I can find out the origin of the error wires, I am hopeful of being able to find/fix the problem ( I have a technical background)
Friday, March 30, 2007 - 04:10 pm, by: Dave Hart(Davyboy)
Tom, I'd be inclined to take the car to Toyota to clear all the error codes (or do it yourself by disconnecting the battery for 15 min) then take it back after you get another error and ask what exactly it means.
Saturday, April 07, 2007 - 10:25 pm, by: Rodger Clarke(Rodger2604)
is this the accumulator ?
i have the brake error light coming up on the dash. after about 2 miles of driving,the pump that runs on start up runs after i apply the brakes then i get the warning light . does this need changing? if so can somebody tell me how to d.i.y or is it better to get the garage to do it ? thanks for your time all ... RODGER