Problems With Abs System

[damtrx]

Hi to all

Recently I notice a serious problem with my ABS system on my IS200 manual

When I press the brake gently the car stops in a straight line. No vibration on the steering wheel or moving on the sides of the road.

When I press the brake pedal hard to activate the ABS System my car starts to spinning . The pedal is "pumping" my foot telling me that the ABS should work , but the car is not performing like it should be .

I went to my local garage and told them for my problem. They checked everything on the car and confirm that the ABS sensors work fine. After a few days of tests they can't tell me what is the real problem. There are no lights on the dash , no error codes on the ECU or something.

My mechanics told me that the ABS pump is failing or the ABS ECU but they can't confirm what cause the problem.

Any ideas or people with the same problem ?

[KentIS300]

It might be a problem with the EBD??

There might not be able to regulate the pressure to the appropriate wheels properly??

I do know a few Lexus and Toyota's had a recall regarding a regulating pipe in the braking system.

I would not know if any IS's were affected by it?

[damtrx]

Thanks for the answer but what is EBD :)I found that if the pressure in the pipes drop ABS system will not work correct.I read the service manual and found that there is a pretty good diagnostic way for this problem.So i think that i have to find another garage in my country/location

And the other thing that i found for now is when someone mess with the pipes and ABS actuator.

[steve2006]

If there are no warning lights or fault codes present and the car stops in a straight line under normal braking conditions why do you think there is a serious problem with the ABS?

If the ABS is activated the pumping you can feel through the brake pedal is normal as the system applies and releases the brakes to prevent the wheels locking up.

ABS is very difficult to physically test on a road test, the nearest way you can simulate testing is on a slippery or icy surface.

[damtrx]

@steve - ABS should not make the car spins. In my situation when I press the brake pedal with ABS activated (extreme stopping) the car tries to make an 90 degree turn. Imagine this with a 100Mph (160km/h) that happened to me few weeks ago.

For me this is extremely important to work because in my country because after a month everything will be in snow or ice.

I know how to test and I know that it depends on the road conditions but on a clean road that looks almost straight the symptoms are the same. Left or right turn depends how the stars are aligned :) (random situations )

Sometimes the car goes left or right , or sometimes the rear end of the car tries to move in front almost like a drift

[KentIS300]

I would look for a seized caliper?.... did you check them?

If they are not seized make sure the pistons are working well

The pins as well

As they tent to rust .... and maybe one side is gripping faster than the other.

I Noticed on my IS that when I refurbed the calipers... the one disk (left) was burned once... but not warped. That side was always slow to grip ... and the car would always pintch to the right (opposite side of the one it had the problem). it seemed as the disk material has lost its ability to perform 100%

[KentIS300]

PS EBD is Electronic Brake Destribution

[damtrx]

@Kentl300 - My mechanics told me that these calipers are cleaned and looks good.

They told me that the problem should be with the pump

http://lexus.solar3.eu/rm/rm684e/m_br_0049.pdf

They told me that the front disks are very worn-out and must be replaced with the brake pads. So I guess that maybe you are right somehow.

This is the test instruction for the pump and stuff so I will try to figure it out how to perform these test

http://lexus.solar3.eu/rm/rm684e/m_br_0045.pdf

[Mr.Rudus]

check your brake weight distribution under braking. as mentioned above earlier it could be something to do with one of your brake calipers sticking or a slight worp on one of the brake disc which the naked eye can not always seem to tell.

I only get this problem when the car is driven hard with high tyre pressures & braking hard last moment going over a pot hole or uneven road surface, the abs slightly rejects as its on maximum pressure.

[damtrx]

I found another garage that have the Toyota SST hand held device that can perform all the test and we will see what is the problem after Friday .

If i have problem with weight distribution my car should be move sideways on every stop not only when ABS is activated on dry road.

[damtrx]

Well today the mechanics from my local Toyota did the diagnostics of the ABS Actuator and all of the braking system. It seems that the front right and rear right solenoids that control the brake liquid stayed open for a longer period compared to the other side. The brake system stops the right wheels harder than the left so my car goes right .

The period is only 0.6sec . They tried with different ABS ECU but with the same results. They are almost 100% sure that the pump is failing so I guess that I'm looking for another one.

The new one is 1250 Euro so I guess that I will buy second hand from eBay. (they are some for 15-30 pounds that is way cheaper )

I will post what happened after the pump is changed

edit: Problem solved. Some idiot had changed brake lines . After we correct them ABS system works perfect