Brake troubleshooting

[cyberegg]

Hi, everyone, long time, no post.....been working on other things.

Having a brake problem, I'd appreciate experienced opinions.

Not long after I bought my Disco '96 occasionally I'd press the brakes, the first time after starting the car, they would shudder, make kind of a grinding noise, but they would work. And then they would be fine for a few weeks. My heart would stop, too. I asked my mechanic about it, he shrugged his shoulders and said it was just the booster not kicking in yet, and not to worry. He also told me that the ABS wasn't working, it would cost too much to warrant fixing it, and the brakes would be fine without it. OK. He also told me the master cylinder was leaking into the booster, and the mc needed to be replaced. I replaced it with a used mc, but didn't have a new rubber gasket to put between the mc and booster, so I reused the old one. I suspect it's still leaking because the fliud is still dropping, but nowhere as bad as before. I plan on fixing it asap...

Well, the shudder and grinding noise when I press the brakes, the first braking after starting the car, is happening more frequently. (twice in the past 2 days) My heart can't take much more. I'm scared the brakes will go out. I don't know what is causing it, I'll probably take it in tomorrow, grit my teeth and pay the mechanic. Any ideas on what it could be?

And I've always heard if the brakes go, to use the parking brake....

Thanks, Summer

 

[Slam]

Summer. You really don't want to take any chances with the brakes. How are your rotors? How are the pads? How are the calipers? How many miles on the vehicle?

 

[discomike]

Well, I thought I might have an idea, but the more I read your post, the more confused I get.
I still think your booster is starting to fail do to the master cylinder leak, which if it has gotten into the booster, will cause a vacuum leak to occur. may be that over night you loose all your vacuum and when you hit the brakes the first time the booster is unable to give its normal presure and makes the noise.
Just a thought,
Mike J.

 

[Jaak]

Could be a problem with the ABS ... sometimes it calibrates it's self the first time you use the brakes. Used to have this problem with my 96 Safari ... ABS sensors could be dirty.

Jaak

 

[cyberegg]

Thanks so much for your help.

On friday, I went to drop off my Disco at my mechanic's......and found out he's moved to the mainland! I've been trying to figure out what to do next, continue working on it myself or? I'm not wild about taking it to the local firestone or equivalent. Or to the upscale Jag / expensive import mechanic that's already been snotty to me. I've been doing some research, since it's appearing I'll be doing it with your help.

Before I replaced the MC, I changed the front pads; calipers and rotors and rear pads all look OK. I've done the Booster / Vacuum Servo Unit test suggested in the Haynes manual, and it passed (depressing the brakes, then turning ignition on). My 96 Disco has 103,000 mi, and I don't think the previous owner did much maintenance on it. I've been trying to fix it up. I wasn't feeling well today (small pain problem), but hope to take a good look at it tomorrow.

I already talked to Atlantic-British about ordering a new O-ring that fits between the MC and booster, but they didn't have it. I called the dealer on Oahu (I'm on the outer island of Hawaii), asked about it, and he didn't know what I was talking about-he said that there isn't anything between the MC and booster. I wish I could just go in, show them, and say "I need this". What do LR owner's do that live out in the boonies?

What do you experts think of me taking the O-ring to the local car parts, or ACE hardware (they have the most extensive selection of hardware here) and try to match it? - I'm a little hesitant to try this.

To clarify my problem a little more: The strange brake feeling happens usually when it has been parked on an angle, altho it's happened when it is parked on the level. It's sporadic. The brakes can be fine first thing in the morning, but the most recent incidents happened later in the day, after I'd driven it back and forth to work, when it was only parked for about 15 minutes after being driven a ways. Is this weird or what? The fluid level is fine, the brake idiot light is functioning correctly. The anti-lock light is lit(always has been), but my mechanic told me it's becauses the ABS is shot. He assured me that it probably wasn't worth replacing it, because the brakes would work ok without it, it just won't have the ABS feature. When it happens, is the first time I use the brakes after it has been off and parked. It usually happens the first one or two pushes, acts like I don't have power brakes, makes a grinding, grunting sound as I push, and I have to push really ******* the pedal, almost standing on it. Then it brakes fine, altho I'm pumping it to make sure. It's hard to break down when it happens, because of the adrenalin rush, and I'm thinking more about what to do next if it doesn't stop. When it first started, it would do it about once every 2 or 3 weeks, and then be fine. That was when I talked to my mechanic, and he didn't act concerned about it. I thought I had it fixed when I replaced the MC, but like I said, I had doubts about re-using the O-ring. When it did it two days in a row, I decided I'd had it, damn all the other fires in my life, and here I am.

For reference, I have my Haynes manual and a LandRover Workshop manual - I purchased it off e-bay, and found out after I got it that it was one of the copyright infringement burned CDs. I feel guilty about it, I'm more careful about what I purchase now, but it's been a great help.

Thanks again, oh-those-that-have-gone-before-me

 

[RoverChic]

Summer:

Is it like a pulsing sensation? Like the pedal is fighting back when you brake(highly descriptive I know)? Have the brakes ever been really hard or really soft (Soft meaning all the way to the ground and still not stopping)? Lastly, did you pull the fuse on the ABS? The ABS is probably a sensor gone bad or has backed out of their seat(s), or the ABS pump took a ****. The fuse is under the hood near the black charcoal canister/maybe behind the battery. HTH

 

[cyberegg]

It's not a pulsing sensation, doesn't seem as if the pedal is "fighting back". It's a Brakes have been the same all along, "soft", matching the description in another brakes post. I'm driving a friends jeep cherokee, and the power brakes on it feel sooooo different, I wish I could get mine to feel that responsive.

Would an OBD code meter help? (I've been thinking about getting one, now that my mechanic is gone. Since I've got a 96, I don't think I've got the on-board code reader, at least I haven't been able to find anything resembling one around my passenger seat?

On a more trivial matter, I don't know why my "signature" says at the end. It's supposed to have a smilie with a smug lsmile on it, I've tried to change it......Can you tell I'm putting off working on the brakes?

 

[cyberegg]

Fuses and links all seem to be okay, couldn't find anything else obvious wrong. Disco Mike gave me some good advice on the "soft brakes" thread. I think my booster is trying to get my attention, and going down for the third time. But I'll ask the same thing on this thread, has anyone had any experience installing a booster and how hard is it?

I picked up some 0-rings at Loewes, but I'm going to try and talk to the dealer again tomorrow about the part I need. I guess I don't understand what is difficult about "I'd like to get the O-ring that is between the master cylinder and the booster"?

I fixed my signature....

 

[virginia]

I am having the same problem and think I know

Hi, I have a 96 Discovery and after getting my brakes changed at the shop my husband is a manager, the exact thing started happening to me. Kind of crunchy feeling the first time you brake when you start up. I find if I pump the brake a couple of times before I take off it doesn't happen. Well, my husband didn't know what it was and we were too scared to find out ($$$) until he had someone come into his shop with a different car make (ford or something) that was doing the same thing only much worse and all the time. It was the abs module. I believe it is the same thing with the disco, when you think about it it makes sense, the brakes are trying to resist your foot because the abs is engaging when it shouldn't be, for some reason the abs thinks the wheels aren't turning for some reason. Could also be a bad speed sensor sending the wrong message to the brakes (that your wheels aren't moving). I haven't had mine fixed yet, because I was told that to replace the abs module was $$$$.
Hope that helps. And please post if you find out anything more. If it helps I have been told that despite sounding really bad it is not unsafe to drive that way.

 

[discomike]

To find out for sure and not buy parts you don't need, have someone use a test book and the brake system, it doesn't lie.
Mike J.