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How do I test to see if the accumulator or pump is working. Should the pump make a noise or vibrate.

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No visual or audio cues from the accumulator. It's just a tank with a nitrogen filled bladder. I can hear the ABS pump working on mine even when driving- gives me a chance to fuel my paranoia counting how many pedal applications between pump runs :-)
What exactly is your problem? You'll know if the pump's not working as you won't have any power brakes. Accumulator failure is normally signalled by the 3 amigos (ABS/ TC/ Brake lights) flashing at you when pushing the brake pedal.

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Just turn the ignition on and you should hear the pump running, mines a noisy bugger so, like Orangebean says, it can be heard while driving. If the accumulator is OK then you should be able to press the brake pedal 3 or 4 times before the pump cuts in, less than that, particularly if it cuts in every time you use the brakes, means it's on it's way out.

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The brakes have always been funny ever since ive had the car. It has never bothered me too much as Ive always had excellent braking power but occasionally the braking would feel weird,usually at slow speed, Sometimes feeling/hearing a judder on the pedal .
I decided to change the accumulator today as I got a new one cheap but I cant hear the pump going and when I think about it I dont think I ever have, the only thing I hear is the eas compressor.

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Are you sure it's the EAS compressor you can hear? I have to put my hand on the box to tell if the EAS compressor is running or not but the ABS pump can be heard easily. When you turn the ignition on after it has been left overnight, it will run for around 30 seconds, the EAS compressor will usually run for much longer than that. If the pump wasn't working you'd know about it, you need to use both feet and all your weight on the pedal just to get it to slow down.

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I will have a listen tomorrow but my EAS is quite noisy, I think its doing overtime as I need to change my front air springs, a job I'm not looking forward to on the side of the road.

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Rears are dead easy but fronts aren't too bad. Getting at the pipe is a lot easier and although RAVE says to remove the wheelarch liner, if you pull it out to get in there and jam a lump of wood or a WD40 can in there, you don't need to.

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There's a possibility that it could be the infamous Brake Modulator failure from the symptoms you describe. Have a read through the 40 or so pages on http://www.rangerovers.net/forum/7-range-rover-mark-ii-p38/15632-please-read-all-p38-owners-up-mid-1999-brake-modulators.html
As an aside, cos I'm too lazy to fix the mounts on my EAS compressor, I can also hear that running when I drive so I can enjoy double paranoia listening to how often that cuts in as well as the ABS pump. A symphony of aural feedback!

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It does sound similar to that Orangebean.
I do get the clicking noise as well but my car is a 1999 Thor and from what I am reading the modulator kit does not apply as RR updated the modulator.

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Updated in mid 99 apparently. If you have 4 wheel traction control, you have the later system

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Is the brake modulator fault a real problem? I'm not keen to start hauling mine apart.

Easiest way to see if the accumulator is poor is to pump the brakes hard a few times. You'll hear the pump kick in but the warning light on the dashboard should stay off. Mine was utterly shot, took two minutes to change, and improved the pedal feel no end.

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Still not sure I can hear the accumulator. I put my ear right to it, I could feel vibration but that could be the eas causing that. The brakes feel no different to before, they work & there are no dash warnings so it must be working I guess.

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Sounds that way. You shouldn't confuse the vibration from the ABS pump running to the EAS pump running. EAS pump is on the passenger side (left as looking from the drivers seat) and the ABS pump is on the right next to the fusebox. I though all Thor models had 4 wheel TC?

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No confusion on location, its just my EAS is extremely noisy and vibrates a lot which makes me wonder if what I'm feeling is the EAS vibration through the engine bay rather than the ABS. People are saying the abs is quite noisy but Im not hearing it.

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Why not try pulling the EAS fuse so that doesn't run? Then you should be able to hear the ABS pump.

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I knew I followed you here for a reason.

Great ideas are usually simple.

Thanks.

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The one you want to pull is Maxi fuse 2 (30A), that supplies power to the EAS pump.

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Maybe time to reset this problem? The only issue is an occasional clicking/ vibration through the pedal at low speeds. In addition you've replaced the accumulator. If the pump wasn't working you'd know it! As Gilbertd says, you'd need 2 feet on the pedal and a few prayers to your chosen gods to stop. You're lucky to have such a quiet pump! I suspect that the occasional clicking/ vibration is an over-sensitive ABS sensor. Maybe the air gap on one of your wheels is a little large. I have to drive a fairly extreme off road track to my workshop and when driving down the hill slowly, trailing the brakes gently, the ABS will always kick in on a particular pothole even though that wheel is not close to locking. I don't actually think you have much to worry about. To get used to what your ABS feels like when it operates, find a muddy lane, bit of grass or whatever and step on the brakes at slow speed. I bet you'll find that's what your noise is.