If I want the best possible brake setup on my 1999 D1 what should I do?

Ever since I have had the Disco the brakes have sucked and when put under a load, like off road, or in the mountains, I lose braking completely.

I have already replaced the MC, removed ABS, put on new EBC pads and rotors all around and SS flexi lines but am less than satisfied and I can barely brake.

I have gotten my brakes flushed multiple times at the dealership and they said air came out of the rear right. Pedal was firm and a week later it goes back to soft. (rear right caliper is new from AB if that helps)

Please help I have already wasted a ton of money
Matt

 

Sounds like you have been throwing money and have not really diagnosed the issue to figure out the cause.

When do you brakes lose feel? When they get hot? Just after a certain amount of time? This isn't a BMW, the brakes aren't very good to begin with.. I find myself giving the pedal a quick pump to build some extra pressure when I need it under hard braking.

 

Exactly that is the most frustrating part, that's why I am here cause I hate doing things twice.

I understand it won't stop on a dime, which I actually compared to new cars that do a stoppie if you barely touch the brakes, however I can be going like 20mph and stomp on the brake, lifting my butt off the seat and it just gradually slows down. Driving on a college campus I really need to stop quickly if I need to.

I know I am getting air comes out of the Rear Right after about a week of driving.

The second part is when they get hot the pedal goes to the floor, like after I go around 2 switchbacks on a mountain road I am forced to pull off

What am I missing???

 

Is the booster any good

 

Not sure but with the engine off pedal is hard and depresses when I start the car so I think its ok but I could be wrong.

 

You have two issues... air in that caliper (which can be anything from the master back to it) and overheating. Grab an IR thermometer and go drive around until you lose the pedal and check the calipers with it. If one is way hotter than the others, inspect and find out why. When you say you removed the ABS.. did you just pull the fuse or did you remove the accumulator and run new lines?

 

I agree that I probably have air in the caliper, which is frustrating because it was "new" but I realize reman. parts are usually worse.

As far as the ABS goes, it never worked when I got it, (had the fuses out) so in an attempt to rule out probable causes for crappy brakes I removed the whole pump and re-ran the lines.

While that modification may raise some concerns the problem was there prior to that and has returned to the same symptoms it had before.

When coming to stops it also feels like a rotor is warped because when coming to a stop it "grabs and lets go", "grabs and lets go" and then sqeeeeks to a stop

thanks

 

You did right by re-plumbing the lines. Did make sure all of the lines are below the height of the MC? You can swap the left and right rear calipers to see if it makes a difference (bleeding will be a pain, you'd have to do it with a block of wood or something off of the rotor) but it is something to try before buying a new caliper. That "grab and let go" does seem like an ABS issue. Weird for sure.

 

I don't see how you could have air in only one caliper without a fluid leak. There's 14.7psi of air trying to get in, and several hundred psi of fluid trying to get out...

Also, in one of your earlier posts about over heating. Two switch backs are not enough to over heat your brakes and loose the pedal.
Brake fluid boils at a rather high temperature. Boiling fluid produces bubbles, when you press the pedal, the bubbles compress instead of the pistons squeezing the rotor... the result is loss of brakes and pedal going to the floor.
Before the fluid gets hot enough to boil, you should have had plenty of warning... the smell alone should have been enough.

The only thing that comes to my mind that would introduce air to one caliper is a steel brake line too close to an exhaust pipe. Hot exhaust could boil fluid in a section of steel line and do some of what you have described... but not all.
When you re-plumbed the lines, did you keep them well clear of the exhaust?

One other thing. Excessive effort to apply the brakes is often the result of a defective vacuum booster... but not always. Don't over look the check valve in the vacuum supply line.
And lastly, boosters can be intermittent, often between individual strokes of the pedal. One time it works, the next time it doesn't. The little valves that vent to atmosphere stick. They even sometimes fail and apply the brakes without your foot being on the pedal.

 

Are your hub bearings too tight? If so they will overheat, overheating the rotors and eventually causing your fluid to boil in the calipers.

Since you say you've had the system bled several times and air bubbles come out every time, I suspect you have a leak somewhere in the system.