Had front-end collision, left front, on a 1995 Grand Cherokee Laredo, ABS disc brakes. Replaced front axle and related parts, kept original brake calibers and everything was fine. After road test noticed smoke from left front wheel, investigated and found the disc to be hot. Assumed brake caliber was sticking, tried to bleed could not unscrew brake bleeder, replaced with another caliber, bled that cylinder and brakes would not hold. Bled entire system, starting with the wheel farthest away, gained brake pedal but when ever I would take foot off brakes, for a minute or two, reapply the brakes, brake would go to the floor. Brake bleeding procedure completed several times.

Replaced master cylinder with rebuilt cylinder, begin by turning on ignition, bleeding the brakes from the master cylinder modulator, loosen and tightened brake line fittings, bled remaining brakes conventional way.

When vehicle is not running the brake pedal is where is should be. Each time after applying brake pedal gets higher as they should but when vehicle is running, when first applying the brakes they go completely to the floor then they will build up where they should be. If you remove your foot from the pedal, wait a few minutes and reapply the brakes again the brakes go completely to the floor with the first pump.

Followed instructions from a Haynes Repair Manual. The manual said to check the booster, place foot on brakes, start vehicle, and the brakes should pull down slightly, which it does. Is this problem associated with an ABS or if the master cylinder that I replaced is defective? Is there some way to check ABS in order to isolate the problem?

Its hard to diagnosic a ABS problem with out a Scan Tool. Once you opened up the system it can require bleeding with a sacn tool. Usally you bleed normal then use a scantool to bleed the system ABS solenoids then re-bleed The conventonal way. Is your ABS light on? and does it saty on after the Jeep is running? Could also be a bad booster but my guess is the ABS sysrem has AIR in it and will have to be bleed with a Scan Tool.

Not sure about bleeding the ABS system, I worked on a 94 GC that had a bad poportioning valve. I replaced the valve, did the conventional bleeding and all was good( I had to go through twice to get all the air out) (conventional, using 2 people, the "one-man bleeders don't work well with the GC's) I would look at your master cylinder first. Those are supposed to be bench bled first, usually it comes with the lines to do this. Then install on the vehicle, with ignition OFF bleed out the rest of the system the conventional way. As far as your ABS system, your solenoidsonly work when required by the wheels locking up. Should not effect your bleeding the system.

Your system for 95 which has Teves Mark 4 ABS bleeding procedure is-1 to do normal bleeding, 2 then a scan tool is used to cycle the pump and solenoids to bleed the system of air, 3 nonmal or basic bleeding is reguired again to remove air. You can get lucky at times and not have to use a scan tool alot of times you do! Some accumaltors have up to 2700 psi and that is why the pump and solenoids are activated during bleeding.