My brakes sound like a machine gun!!!!! 90 RRC

[kjj0506]

There is suddenly an intermittent rapid fire tick coming from under my dash near the pedal and when this happens the braking goes whacky and I can't stop. The pedal is kicking back when the this occurs as well. It seems as though its trying to go into antilock mode but I am at parking lot speed and in no threat of skid...

I would love to disarm the ABS if possible and have seen info in places about  disconnecting the sensors. Would my symptoms be cured by this ? Does some one have detailed ( read: chimp-proof ) instructions on how to rid my ABS woes ?


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Definitley sounds like your ABS is kicking in.

 Try giving the reluctor rings on each wheel a go with a wire brush. The reason it is coming on is that the system thinks that one of the wheels has stopped rotating or rotating alot slower than the others, so the problem is more than likley located at the business end. The only other thing I can think of is checking the air gap on the sensors themselves. (I don't know whether it's adjustable or not)

After that it gets more complex :?  start with the simple stuff 8)

[Guardian.]

sounds like one of the abs sensors gone u/s.
but not gonna tel you anymore.
cus i dont know anymore!
but hopefully will not be to bad to fix, i did bypass the abs on a rrc a few years ago, from memmory what isnt very good, we just bypassed everything, i dont think it takes that much to do, definately did it in a day / morning, just have to make up a few pipes, im sure we used the same servo, master cylinder ect.

[waveydavey]

I would think that you could disable it by pulling a fuse or something equilly basic?

You will get a lighton the dash which in the UK is an MOT fail but I don't know the rules over there.

Mind you ABS is good stuff; especially in places where you get snow!

[Evilgoat]

No MOTs so no fail :)

As already mentioned, the ABS ECU thinks that you have a locked wheel. Clean the reluctors off and take a look at the sensors. I've had an ABS lamp before now because the sensor had actually fallen out of the hub!

[kjj0506]

How should I go about making the reluctor and sensors clean ? Isn't there hub disassembly and such involved ? I just had the front right apart to freshen the leaking seals for the Swivel ball..... dang ! Shoulda done it while I was there huh?

A friend said to just clean the sensors as well but I can find instructions on removing them in the limited manuals that I have .

and ... yes , Senor Wavey , I agree ABS is certainly a good thing when working properly but when its malfunctioning and as problematic as these systems ( and as expensive to repair ) can be ...sometimes it's more reasonable ( read; affordable for me ) to disarm it and plan for later ....

thanks all who help ...

[Range Rover Blues]

Ok, the front sensors are inside the top swivel pin, held in by a clip that should be replaced if they are ever removed.  The exitor ring is cut into the CV joint ans as this runs in oil, doesn't suffer from rust.

A loose wheel bearing or exhuberant off-roading can force the sensor out but you should be getting a dash board light, assuming the US spec ABS works the same way!

The rear exitor rings are bolted tot he very inside face of the disks, the sensor sits on top of the axle tube and is secured in the flange that the stub axle bolts into, the stub axle flange has a cut-out for it.  These can get covered in muck if the hub oil seal goes and again wheel bearings etc can drive the sensor out of line, resulting in a fault.

The condition of the ABS can be tested by a blink code test on an ABS system that's working, though I've come accross one that wasn't and wouldn't play ball.  I've also seen one whewre some nugget wired the ABS light to the ignition light to fool the MOT tester.

That's damn stupid, the back brakes are only operated by the ABS, not by your foot and only the primary front circuit is pedal operated too, the rest relies on the ABS, so pulling the fuses out is just asking for trouble.

First thing then, do you get the ABS warning light at startup? it should stay lit untill the car goes above 5mph, during this phase the system is in diagnostic mode and checking the sensors.  Once all wheels have gone above 5mph the system drop diagnostic mode, unfortunatley you cannot then read the inputs by any means :roll:

[carbore]

I once had the same issue on a VW golf.

I put an ohm meter over the abs sensors and the faulty one registered as a dead short, all the others had a resistance of the same value

(I did cheat and also tried diags software so I knew that the ohms test was valid, I actually only tries the meter as id read it on tinternet and wanted to know if it worked)

It may be worth trying this so you can get the right (or left) one as the sensors may be haded, but I dont know anything about range rover specifics.

good luck.