Jeep Grand Cherokee brake trouble

I’m at a loss and I can’t find suggestions of things that I haven’t already replaced. I’m going to start at the beginning so this may get long.

About a year ago my brake pedal started acting funny. Sometimes it was normal, other times it would be nothing till almost the floor but Ive never not been able to stop or even had increase in braking distance. I never even felt unsafe driving it aside from worrying if and when they may stop working.

A few months ago the pedal stopped ever getting hard. Always to the floor but always could stop fine. My control arms got really bad so I stopped driving it till I got money to fix them. Replaced them, the master cylinder and the brake booster. Bled all the lines. Couldn’t get bleeder on rear right open my dad bled from where the flex hose connects to the caliper. While bleeding these, I was pumping the brake pedal. I don’t know if it’s relevant but when bleeding the rear, pedal is firm with 1 pump. When bleeding front left, took 10+ pumps or about 30 seconds of waiting. When bleeding from front right side I could never get a solid pedal. Every pump went to the floor but fluid always came out. Eventually got no air from all tires but still spongy pedal. We bled forever. Bled from master, bled from abs and all tires over and over, no air.

So I bought a vacuum pump. I hooked it up everywhere. First each tire except rear bleeder that didn’t work. So rear and front right bled with no air, vacuum held suction. Bled from front right and almost all air, hardly any fluid. Followed that line to the abs, bled from all spots on abs, no air. Bled straight from master with the pump, no air. Everything held suction like it should. So I replaced the front right caliper, still consistent air. I unhooked the line from the abs and submerged it into a cup of brake fluid, bled from caliper, all air. Took the line off the caliper and submerged that end in water, bled from abs side with vacuum, straight fluid, no air. I replaced the flex hose, still same results.

I don’t understand how vacuum bleeding the line one way gives me air bubbles and reversing the flow of the fluid gives me straight fluid.

When using the vacuum method to bleed brakes, air can leak past the threads of the bleeder valve causing small bubbles in the brake fluid.


1 Like

I would replace the caliper that you cannot get the bleeder valve open. even though you bled the line you can have air in the caliper. always bleed from right rear first then left rear, then right front and then left front, always making sure the reservoir is full. And I am sure you know to make sure the bleeder valve is closed before lifting your foot off the brake pedal.

1 Like