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Brake Warning Light going on and off

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  #11  
Old 12-17-2018, 08:59 PM
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You found your problem.. Unless you are very mechanically inclined use the replacement master cylinder as suggested by Best.
 
  #12  
Old 12-18-2018, 01:41 AM
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Your fluid goes down in the reservior as the brake pads wear, too. So, it may not have a leak...just the pads are wearing down from normal or abusive driving. It is normal to have to add/check brake fluid during the lifetime of a brake pad. So, with that being said...just keep an eye on the fluid level from here on out, and in the near future...check the conditions of your brake pads and rotors. Also, if you have a nice stiff pedal, no drop after applying (no dropping to the floor while holding pressure for length of time), no seepage below master cylinder and good stopping sensation...l'd say the reservior and master cylinder are probably fine. Yes, they can leak internally, past o-rings...but you usually get a weak pedal or sometimes have to pump the pedal to get a good stiff pedal.

Also, cracks me up that you let your son go rock crawling with a brake fault light going off on dash...must not like the kid much...lol.

Brian.
 
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Old 12-18-2018, 10:54 AM
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Not rock crawling, rock climbing -- just drove the D2 out to his favorite climbing area.

The pedal does seem to be a little soft and my take a pump or two to stiffen up, but can't check right now as I am out-of-town at the moment.

I recall that if you crack open the abs system,you need to reprogram it (the abs system), but I am guessing that if I just replace the master cylinder, then I'll only need to bleed it the same way as if I had removed a caliper and will not need any regrogramming. Am I right?
 
  #14  
Old 12-18-2018, 11:14 AM
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If the paint is missing from the black master cylinder = it’s leaked at some time or another (they tend to leak more in the cooler months in TX). Easy way to spot if someone has repaired the seals at one time or another = the reservoir itself. From the factory the reservoir has Land Rover on it, and if it’s been replaced along with the reservoir seals it will not say Land Rover on the reservoir. Replacing the MC is a breeze, disconect the lines, remove it, install new one, fill with DOT4 brake fluid & loosen the two lines that go to the WABCO ABS Unit. Then bleed the MC from there, and once you have a good flow of brake fluid tighten up the two lines, then go to your fuse box under the hood, remove the ABS relay & use the F/R slots and connect a 15-20ft piece of 2 conductor wire into the relay slots, then just have a toggle switch or push button switch on the other end, then crawl under the D2 and do RR, LR, RF, LF, flip the switch the ABS pump will run, open the bleeder, and do it a few times until you have fresh clean brake fluid coming out. Then close the bleeder, top off the MC if needed, and move onto the next wheel.

 
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Old 12-18-2018, 11:27 AM
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Originally Posted by austinlandroverbill
Not rock crawling, rock climbing
Who would want to climb rocks by hand...when you have a rover available...lol.

Yeah, sounds like you may have a bad master cylinder if brakes are soft and need pumping.

Brian.

 
  #16  
Old 12-18-2018, 02:49 PM
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Originally Posted by Best4x4
...then crawl under the D2 and do RR, LR, RF, LF, flip the switch the ABS pump will run, open the bleeder, and do it a few times until you have fresh clean brake fluid coming out.
The RAVE says to bleed in the order RF, LF, RR, LR (page 70-31). Has the collected wisdom of this forum amended that?
 
  #17  
Old 12-18-2018, 03:24 PM
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I don’t look at the RAVE manual everytime I touch a LR. On all the other vehicles I’ve bleed the brakes on you always start from the furthest away & work your way up to the closer ones. Whatever wheel you start at doesn’t really mean a hill of beans in the end so do as you want. The main & very important thing to do is get all the air out of the brake lines!

I guess my workaround on how to bleed the brakes by jumpering the ABS pump is bad info as well. Pretty sure the RAVE manual will mention using a T4 to bleed the brakes properly.

I understand why LR is saying to bleed from the closer to the furthest wheel, but by just changing a brake line or a master cylinder you are not going to introduce that much air into the system normally. Now if you changed out say the WABCO ABS Unit then yes I’d follow the RAVE manual to eliminate air from just being pushed around the system.

To the OP just take your LR to Austin Roverworks. Ken Parker, Billy Atwood, and Justin will fix you up if you aren’t comfortable doing it yourself.
 

Last edited by Best4x4; 12-18-2018 at 03:43 PM.
  #18  
Old 12-18-2018, 04:30 PM
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I don't refer to the RAVE every time either, but this is the first time I've ever worked on a vehicle with ABS so I tend to follow others' recommendations when dealing with those systems. I was just wondering if you had any specific reason for doing it in the order that you do. (I would normally go furthest-closest myself but since the RAVE method doesn't go closest-furthest I figured there must be something behind its specific order.)
I just ordered a replacement master cylinder unit based on the recommendations of this forum (particularly this thread) so I will be bleeding in the near future.
 
  #19  
Old 12-18-2018, 05:32 PM
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I agree with Best4X4. I've been a mechanic for forty some years, yes...this makes me older than dirt. But, in all bleeding situations l've read, used or observed...you always start in the farthest bleeder from master cylinder and work to the closest. Why LR does it opposite...l have no clue. However, l have no clue why they have a heater control that has to go back to the lowest setting from the highest (instead of just going back to the next lower setting), or why your fingers have to play "twister" while trying to close all four windows at once, or why you can't decelerate the cruise control, or why they made the drivers compartment for midgets, or why they etc, etc...

Anyhow...

​​​​​​​ Brian.
 
  #20  
Old 12-18-2018, 07:05 PM
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The reason LR is advising it is "if" say you had the WABCO unit out you could get air trapped in all four lines directly at the WABCO unit and it's a "possibility" that you could just push air around inside the system if you don't bleed it from the wheel which has the shortest line to the WABCO unit. This makes sense, but at the same time it doesn't. You don't normally bleed a D2 manually anyways for the best results. With a T4 or equivalent LR scantool (or my backwoods jumper wire/switch at the ABS relay) you'd purge the WABCO unit first, then power bleed each wheel so with that being said air trapped inside the WABCO unit shouldn't happen anyways.

I normally end up doing brake jobs on LR's that haven't seen a brake fluid flush in a very long time so the fluid is brown vs almost clear, so whenever I'm bleeding I push a lot of fluid thru the lines until it runs clear. I've always done RR, LR, RF, LF on a D2 and the pedal comes back nice and firm and the LR stops great. I've also in the past done a single power bleed then take it for a spin, find a hill and enable HDC just for kicks, and then go back and bleed it again, but lately I've just used either my Nanocom or my old faithful backup the wire & switch. I had one D2 that always came back with a nasty pedal. I probably bled it 3-4 times until I tracked it down to a vacuum leak on the booster line at the intake manifold. After I fixed that I had a nice solid pedal.

Whenever I do a MC replacement I think the key is to bleed it above the WABCO unit itself via the two main lines. I've seen some people just slap a MC on, add fluid and then power bleed it or bleed it manually and they always complain about a spongy pedal after bleeding and that to me is introducing a lot of air into the system.
 


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