Good Day to you ladies and / or gents,

I've been lurking on the forum for years benefiting from your posts and responses to fix up my 2003 Disco 2 V8 but today I find myself finally posting myself with a damn head-scratcher Ive been dealing with for a couple months at this point.

I wanted to get fresh pads, rotors, and replace brake fluid. Fair enough no issues until I go for a test drive and notice my brakes locking up a little bit at a time, eventually car would not move when letting off the brakes at idle and would have to hit the gas just to get moving to get back to the driveway. Cue the rabbithole to hell, I read around and figure okay my flex-hoses are ancient lets change those so I do with the upgraded hoses from Atlantic British. Take it for another test drive, same problem, bring it back to the driveway and notice some of my caliper boots are deformed and my calipers are generally nasty so I order all new calipers from RockAuto - Cardone remanufactured. Take her for another test drive and frustratingly , same issue, all 4 wheels lock up. Now I'm getting angry, what can it be ? I crack the fitting at the master cylinder after reading I might have a clogged relief hole in the master considering I stupidly bled gross years old fluid down the whole system, so new master cylinder is now installed, took it for a test drive again felt a bit better but sure enough after enough driving around and braking the brakes progressively locked up and I had to curse it back to the driveway a few minutes later. I don't believe its the brake booster push rod being set at too far a length to allow the cylinder to retract enough as I did not change the setting at any point during the repairs / replacements and my brakes worked just fine before. Now I'm ordering a Nanocom unit for my Disco 2 V8 to bleed the Wabco ABS unit as its the only thing I haven't replaced and I have read some reports here and there that the modulator could be in need of bleeding which can only be done with an adequate diagnostic tool ? So if I receive this Nanocom after burning 600 bucks and the ABS bleeding process doesn't fix this I am damn near close to throwing in the towel here. Any tips you wise sages may offer would immensely appreciated, thank you all.

Cheers !

 

Traction control sounds like a possible culprit, your ABS module could be wonky. It would be a pain but you could unplug the speed sensors and see if goes away, but you will have the 3 amigos.

 

you can power bleed without using a Nanocom just FYI

 

It sounds more mechanical than electronic to me, so my guess is that the Nano (as much as I love it) won’t fix it. I’ve never had such an issue on my Disco, but I did on my 2A after replacing the Master Cylinder. IIRC, the MC was set too tightly and wasn’t releasing enough to let the fluid return. (I don’t think you’ll regret buying the Nanocom though).

 

Thank you all for your earnest replies ! Was fiddling with it today , took it for a short drive to let the brakes start dragging on the rotors then parked it and loosened the two nuts holding on the master cylinder to the booster and as soon as I backed it off a bit from the booster I tested the wheels and they were turning free. So I should be relieved it wasn't something worse involving abs at this point though I imagine when I was having the issue with the original master cylinder it couldn't have been a maladjusted push rod , may have been a gunked up cylinder from the bleeding. Either way now my main concern is adjusting the push rod which seems to be ridiculous considering the rod is hiding in the booster, guess truck might be to have someone hold the brake pedal down so it's sticks out while I try to adjust it. Anyone have any tips or pointers for getting the right adjustment length for the booster rod ?

 

"Some" aftermarket master cylinders = the back piece is slightly thicker which causes the adjustment rod to act longer. Which causes the brakes to lock up or stay locked.

 

I’m glad you’re figuring it out. Thanks for keeping us updated.

 

Took the master off again to try to adjust the booster rod. As I was fiddling with it it came off the booster and I pulled it out completely, made my job of adjusting way easier - took it to the vice and the booster push rod takes a size 7 socket - took it all the way down to it's minimum setting. Placed the booster rod back where it goes in the booster and placed the master cylinder on the rod, can't get the booster rod to stick itself to the booster like it was before but mechanically seems to be performing as expected. as I'm going for a test drive I feel the brakes locking up and I get out and back the two master cylinder bolts off the booster to increase the travel but I'm pretty much near the end where the nuts would come off and it seems to not be where it wants to be yet to perform normally. As I drove and stopped then backed off the nuts every time the brakes seemed to be dragging less but it seems ridiculous to have to come this close to where the nuts are going to come off.

 

Maybe the adjustment should have gone the other way.

 

It may be a failed master. You can try pouring cold water on it when the wheels lock and see if they release. Happened to me more than once with other cars.