Hi my brakes are starting to become very dangerous. i had problems with the abs activating during normal breaking, and as a result the steering wheel would pull to the left. i could hear the abs pump pulsating. my mechanic cleaned all wheel sensors, they were pretty dirty, and checked the wiring. sometimes the abs light would come on, but also went out again. it now evolved in the situation that sometimes, when i break, the pedal is hard, and when i brake harder, while hearing the abs pump work, the pedal would suddenly go deeper as if something had been stuck under it and slipped away. today this happened, i wanted to break on the end of a highway exit, but it was harder then normal. when i pushed it further, suddenly it 'jumped' further, the abs was pulsating and the steering wheel pulled to the left sharply... very dangerous and my heartbeat went crazy...! the abs light came on, and when i tested it on a slippery road i noticed that the abs was not working anymore, and the problem also didnt happen anymore when the light was on.

i hope someone can help me here....! thanx, Pim

 

pimmow,

I would take a deep breath and take the ABS valve block apart. The symptoms you describe seem to imply that one wheel is acting under ABS conditions whilst the other wheel isn't. That's typical valve block inconsistency. There are quite a few threads here discussing the valve block and also a number of members who have taken the block apart. The typical problems are dirty, corroded valves and an ageing printed circuit.

Do a search on the Forum and you'll find a variety of threads. Read them all and then dive in.

Good luck

Paul

 

Do you know if you have the Teves III or IV brake system?

If you don't know, you either have a ball shaped accumulator on the passengers's side of the engine, up by the firewall, or you have a large cylindrical accumulator on the drivers side of the engine bay, also by the firewall.

 

Hi Vee, it's the latest system, so teves 4 then? it has the black cilinder on top of the abs module.

thanx, pim

 

Good question Vee,

I was guessing (incorrectly) that it was the earlier system with the problematic valve block.

Pimmow,

Apols, I've misled you. The later systems are not renown for the problems now being experienced by the earlier systems.

Paul

 

Hi pimmow

Could it be the Vacuum Tube is Blocked?

 

sorry, i dont know which one you mean? Where is it? Thanx

 

Hi pimmow

I've got a car the same as yours but She's all covered up at the moment, so I cannot get to the engine in order to take a look but on my V12 the Brake Servo on the side with the Pedal Box has a Vacuum Pipe connected to the inlet manifold

Not sure about my 95 but wouldn't be surprised if she has got one, so maybe someone will know

 

Is the ABS light blinking, or just on steady?

The only common issue to this brake system is that the sensors get dirty and lose their ability to read the wheel. My front passengers wheel sets a code every now and then. A cleaning usually takes care of it for awhile.

It's difficult to access. Anytime you're servicing the suspension there, it would be worth it to go in there and clean it out. If you pull the brake rotor, you'll have an easy go of it as well.

Ultimately when the ABS decides it's not working, you have a normally, non-ABS brake system. Still completely safe, just not enhanced with the ABS benefits.

 

I had similar symptoms with a strong pull to the left and it turned out to be a collapsed caliper hose on the other side.
Replaced bot with a pair of braided hoses and the problem went away.

 

i think this is not the issue since it only happens sometimes; and at the same time the abs activates without reason. When the abs light is on, there are no issues.

thanx, pim

 

hi already cleaned all sensors without succes...thanx, pim
the abs light is on constantly now, and the problem disappeared. Before it was off. And it acted very dangerous, as i described.

could it be the issue with the abs module solder contacts being broken? Not sure if it also was the issue with these years, but ive read several messages about this.

thanx, pim

 

hi already cleaned all sensors without succes...thanx, pim
the abs light is on constantly now, and the problem disappeared. Before it was off. And it acted very dangerous, as i described.

could it be the issue with the abs module solder contacts being broken? Not sure if it also was the issue with these years, but ive read several messages about this.

thanx, pim

 

Odd. I'd love to get that code pulled and see what the ABS is telling you is wrong. Unfortunately, to pull the ABS codes, you'll need a Jag-specialized reader....

 

Hi pimmow

Check all the Fuses under the Passenger Kneepads (UK) Car maybe the one for the ABS is either Blown or Corroded and not making proper Contact