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Discussion Starter · #1 ·
Hey every one Im new to the forum here and looking for some help. I have a 2002 P38A with a serious abs issue, everytime I apply my brakes the ABS engages more so on uneven surfaces thus making the car extremely unsafe at any speed. There is no ABS or TC fault coming up and ive pulled and checked all the sensors and they seem fine. Im no stranger to Range Rovers and know that it is not typical for the brakes to act in this manor. I dont mind loosing ABS, I did away with it on my disco when a reoccurring ABS fault nearly killed me. When I pulled the fuse on the P38 (fuse 25 if I recall) I had amazing brakes could stop on a dime and even get it to lock up, but my speedo and odometer cut out and I cant have that happening so I put it back in. I know fuse 23 works on pre 99 Rangies to disable ABS and keep speedo working but is there a way on the 02.. Boy do I miss my 96 HSE this 02' is a real POS with its bosch molested 4.6 and silly doodads trying keep the archaic P38A competitive in 2002 they should have left it simple.

My interpretation of the "ABS engaging" is pedal gets hard, kicks back, groans, ratchets and pulses, while the car literally grinds to a halt, lurching as the ABS pulse. During all of this my hand is constantly griping the E Brake so a human can intervene when the computer controlled system fails as a child crosses the street.

Does anyone know what could be happening? No faults and brakes that will soon enough kill me or others in the state they are now
 

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LIFETIME CONTRIBUTOR
2002-2005 Range Rover MkIII / L322
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5,668 Posts
Check the part. no stamped on the brake booster/modulator. The symptoms you describe certainly apply when a later unit is fitted to an early car.

Dunno if the reverse applies.
 

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Discussion Starter · #3 ·
Ill check the part number tomorrow, but you say the symptoms are typical when you put the later part in an early car... Mines an 02 about as late as a P38 gets. I was going to put all the ABS parts off my 96 HSE on the 02 until I found out they were different
 

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Hi,

This is a good question... My RR is doing something like that.. Can I disengaged ABS without lose the TC? There is any way to do that? The ABS on my RR just turn it on a unsafe vehicle, you hit a something on the road while you are braking and brakes just go lose.. ABS it's not effective on the RR...

Regards,
 

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Discussion Starter · #6 ·
looking at the Rave would unplugging C506 from the ABS ecu have all the effects of removing fuse 24 without the loss of speedo and odometer readings? or will I just be left with no brakes? Im going to retrieve the part number off my abs booster/modulator when I get home to rule that out, and maybe take a trip to the rover shop to check that relay.

C506

1
Front left ABS solenoid control valve
Output
2
Front left ABS solenoid control valve
Output
3
Reference earth
Input
4
Front right ABS solenoid control valve
Output
5
Front right ABS solenoid control valve
Output
6
Not used
-
7
Rear left ABS solenoid control valve
Output
8
Rear left ABS solenoid control valve
Output
9
Not used
-
10
Rear right ABS solenoid control valve
Output
11
Rear right ABS solenoid control valve
Output
12
ETC Normally open solenoid control valve
Output
13
Isolating valve
Output
14
Isolating valve
Output
15
ETC Normally closed solenoid control valve
Output
13
Not used
-
14
Brake pedal switch 2 (normally open)
Input
15
Not used
-
16
Not used
-
17
ETC warning lamp
Output
18
ABS warning lamp
Output
 

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Hi,

I have similar symtoms with my 98 HSE 4.6. A small bumb or curb will set off my abs and tc rendering the brakes pretty useless. Additionally I have very little braking power when in reverse - which makes backing out of hilly driveways quite dodgy. When I start the car, the abs and tc lights stays on for a while (over 10 secs), and seems to stay on till I pushing the brake pedal. Its been of the road while I was rebuilding the eas, which is now working reasonably well.. well enough to look at fixing the brakes. Man this car has been frustrating, so many things dying at once!

I was considering downloading the abs book from falconworks, has anyone got it? is it worth buying? http://www.jewellamberoil.com/sales/ind ... cts_id=230
 

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2002-2005 Range Rover MkIII / L322
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callum76 said:
Hi,

I have similar symtoms with my 98 HSE 4.6. A small bumb or curb will set off my abs and tc rendering the brakes pretty useless. Additionally I have very little braking power when in reverse - which makes backing out of hilly driveways quite dodgy. When I start the car, the abs and tc lights stays on for a while (over 10 secs), and seems to stay on till I pushing the brake pedal.
The ABS and TC lights will stay on until the car has exceeded a certain speed.

Braking power in reverse should be the same as when travelling forward. They are disc brakes (not drum brakes with leading shoes which become trailing shoes when travelling backward and thus not self-energising). However, if you are going ito reverse immediately after startingf and before the brakes builkd up brake pressure, then yes, you will notice a distinct lack of breaking. If that's happening, it is likely your accumulator needs replacement.

Do a search on here to see how to test it.
 

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Nacra52 said:
Hey every one Im new to the forum here and looking for some help. I have a 2002 P38A with a serious abs issue, everytime I apply my brakes the ABS engages more so on uneven surfaces thus making the car extremely unsafe at any speed. There is no ABS or TC fault coming up and ive pulled and checked all the sensors and they seem fine. Im no stranger to Range Rovers and know that it is not typical for the brakes to act in this manor. I dont mind loosing ABS, I did away with it on my disco when a reoccurring ABS fault nearly killed me. When I pulled the fuse on the P38 (fuse 25 if I recall) I had amazing brakes could stop on a dime and even get it to lock up, but my speedo and odometer cut out and I cant have that happening so I put it back in. I know fuse 23 works on pre 99 Rangies to disable ABS and keep speedo working but is there a way on the 02.. Boy do I miss my 96 HSE this 02' is a real POS with its bosch molested 4.6 and silly doodads trying keep the archaic P38A competitive in 2002 they should have left it simple.

My interpretation of the "ABS engaging" is pedal gets hard, kicks back, groans, ratchets and pulses, while the car literally grinds to a halt, lurching as the ABS pulse. During all of this my hand is constantly griping the E Brake so a human can intervene when the computer controlled system fails as a child crosses the street.

Does anyone know what could be happening? No faults and brakes that will soon enough kill me or others in the state they are now
You've checked the wheel speed sensors then? It can be difficult to test a hall effect sensor and get reliable results, at least in my experience with ABS on a few different vehicles.
 

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p38arover said:
callum76 said:
Hi,

I have similar symtoms with my 98 HSE 4.6. A small bumb or curb will set off my abs and tc rendering the brakes pretty useless. Additionally I have very little braking power when in reverse - which makes backing out of hilly driveways quite dodgy. When I start the car, the abs and tc lights stays on for a while (over 10 secs), and seems to stay on till I pushing the brake pedal.
The ABS and TC lights will stay on until the car has exceeded a certain speed.

Braking power in reverse should be the same as when travelling forward. They are disc brakes (not drum brakes with leading shoes which become trailing shoes when travelling backward and thus not self-energising). However, if you are going ito reverse immediately after startingf and before the brakes builkd up brake pressure, then yes, you will notice a distinct lack of breaking. If that's happening, it is likely your accumulator needs replacement.

Do a search on here to see how to test it.
TC should go off fairly quickly...ABS stays on til 5mph IIRC.
 

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NikeCheck246 said:
p38arover said:
callum76 said:
Hi,
They are disc brakes (not drum brakes with leading shoes which become trailing shoes when travelling backward and thus not self-energising). However, if you are going ito reverse immediately after startingf and before the brakes builkd up brake pressure, then yes, you will notice a distinct lack of breaking. If that's happening, it is likely your accumulator needs replacement.
Do a search on here to see how to test it.TC should go off fairly quickly...ABS stays on til 5mph IIRC.
I'm aware of drum pad direction, have previously ownded 2 older landies and a cruiser - back in the day I rebuilt my 52 series 1 with cruiser running gear and a 283 :). I ESPECIALLY don't reverse as soon as the car is started.. I'd have no breaks at all if I did that! Not sure why it would be worse in reverse - perhaps its just because where I park at work is on a steep driveway so I notice it more. Sure does sound like an accumulator problem, I'll have a poke around to learn how to test it and report back. Just for interests sake my HSE has freshly-ish machined discs and new-ish pads all round. Thanks for replying, much appreciated!
 

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ghur said:
A bad accumulator does not cause constant running of the pump. A good way to check its operation is to switch on the key and wait for the pump to switch off when the system is pressurised. Then apply the brakes a few times. If the accumulator is bad the pump will run virtually every time the pedal is pressed - maybe every second one. You should get four or more applications before it runs.
When I switch the ignition on it takes about 4-5 secs for the system to pressurise (whining whhaaaar kinda noise). When I press the pedal the pump comes on every time, with out fail, and the TC light turns on with each press of the pedal. I have bled the system in the past - at the time I was not aware of the insanely complicated bleed proceedure (which I've just read) is it possible it just needs a propper bleed?
 
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Possibly, but not likely. That noise you hear every time is the pump kicking in because it's not using pressure from your accumulator, because it's shot.
As said above, test the accumulator, replace (fairly straight forward) and both forward and reverse brake operation should improve dramatically.
 

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Mr. Range Rover said:
Possibly, but not likely. That noise you hear every time is the pump kicking in because it's not using pressure from your accumulator, because it's shot. As said above, test the accumulator, replace (fairly straight forward) and both forward and reverse brake operation should improve dramatically.
1998 HSE 4.6
I tested my accumulator (described in my previous post) and yes as suspected it apprears poked. However I didn't describe this next bit in my initial post, the other issue is, after starting the car (after it has sat over night) the first pump of the brake pedal almost goes to the floor - after 2 or 3 sucessive pumps the brake pedal feels normal. I've just visited the local rangie fix-it guy to pick-up a new accumulator but he actually talked me out of it - he suggested that although the accumulator will fix my original problem, it won't remedy the soft pedal in the morning. In his experience this is a failure of the one way valves in the pump. He sends the pumps away to get the valves drilled out and replaced, but its costly (about $1000NZ). Has anyone had any experience with this?
 

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"TC should go off fairly quickly...ABS stays on til 5mph IIRC"
Not in mine it doesn't. Takes 300-400 yards, no matter what the speed.
 

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Hmm. Sounds like this light going off thing can vary widely. Mine always goes out pretty quick, it's off before the end of the driveway (about 40 yards) and seems to go off at a very low speed, perhaps 5mph, certainly no more than 10mph.

Clarification - I mean the ABS light above.

The TC light goes off a few seconds after it's started up.
 

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Mr. Range Rover said:
sounds like a vacuum leak somewhere in the system (maybe master cylinder). Could be valve leak as well.
Well i've ordered an accumulator anyway, so will chuck that in and hope for the best.. sounds like I've got more to consider though. Thanks very much for your input!
 

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Cornishman said:
"TC should go off fairly quickly...ABS stays on til 5mph IIRC"
Not in mine it doesn't. Takes 300-400 yards, no matter what the speed.
Your pump may be running longer than it should. Sometimes, if I jump in my car and try to take off quickly, my three amigos take a little while to go off. If I wait for the pump to quit cycling, it goes off at 5mph.
 

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callum76 said:
New accumulator is in, brakes are bled, reservoir cleaned (as much as possible), problem pretty much solved.

The brake reservoir was seriously gunked up inside, i called my local rangie guy (Top Of Range) and he claimed to have never sold a replacement reservoir so I pulled it out and spent about an hour or 2 attempting to clean it with fuel-lite, brake cleaner, turps, and an air compressor. Before I cleaned it out fluid barely dripped out, afterwards it was trickling out so some improvement.

First thing in the morning I still get a slightly spongy pedal (to about 1/2 way) for the first press if I stomp on it as soon as I've started the car, but after that the brakes are all good. Pedal feels good, abs and tc lights are behaving normally and the brakes work in reverse now too . Its been suggested I probably have a leaking return valve and this might well be true but I'll never find out because i'm going to sell this worthless p.o.s. if anyone will buy it! (this comes from someone who genuinely loves landrovers). At least its road worthy now!

I've never had so many problems with a car and they're not even all fixed, I still have steering play and the aircon works randomly!
I've posted my reply to the topic 'Brakes! Need help in determining cause?'
viewtopic.php?f=3&t=34333
 
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