BMW X5 E53 Rear Brake Hose Change

[@BenJamesNewman]

Hi mate, cracking video. One of the best step by step's I've seen on KZbin. Easy to understand and to the point. Problem is this gave me too much confidence to try myself and whilst left with two brand new (not leaking) rear brake hoses I have a very soft peddle after bleeding all 4 corners :( I'm guessing I might have a unique problem, in that the rear n/s brake hose was corroded and broke, leaking the contents over the driveway over night until there was nothing left in the line. When checking the reservoir in the morning the fluid had gone down to the minimum/bottom of filter. So, I replaced both rear hoses (little to no fluid came out, no need to clamp off), then filled the reservoir back up to max, attached the pressure bleed bottle with half contents full of new fluid, pressurised to 10/12 psi and bled all four corner in this order RL, RR, FL FR until no more bubbles, kept the bottle top off with fluid and pressure, reservoir never dropped below max or introduced air bubbles. (Didn't need to change front hoses, but bleed all four as don't think its has a fluid change in 15 years.) No bubbles whatsoever from front lines. I did not pump the brake peddle or start the car at any point since the hose broke, until I finished the complete process to test. Result is a semi hard peddle when engine off and pumped a couple of times, then peddle goes soft and almost no resistance straight to the floor with engine started. It is activating the callipers though enough to stop a gentle roll forward or back. Any ideas mate? I keep reading that I might have to activate the ABS pump using INPA and a cable, as because the line on one side emptied I could have air in the module? However the reservoir never fully emptied, could the master cylinder have been run dry from the rear callipers to the back of the piston? Why would this have left a minimal amount in the reservoir and not fully drained though, may this also suggest a broken seal in the master cylinder as clearly can't be completely sealed between front and back side of piston? All I have is the BMW Scanner 1.4 software and OBD which I don't think is compatible with INPA for ABS activation. Any advice would be greatly appreciated.

[@retromechanic2238]

Hey BenJamesNewman - I don’t usually come back to videos this old but I see your going through the motions a bit buddy & put a huge amount of detail into this comment so I thought it was only fair I respond. That is quite a unique fault, I think despite the reservoir “not fully emptying” - it’s still hard to determine if air has made its way to the module - because what “can” happen is air can travel back up the line if it’s low pressure & open to the elements (like yours - if it’s broken, it’s not sealed, there’s a pressure drop & air could have entered into the line from the break & travelled UP) - really hard to say but with the symptoms I would say there is still 100% air in the system. It may just be, air knocking about the caliper area & you just need to keep on bleeding - whilst the fluid is coming out of the nipple, a few light taps on the caliper with a hammer will aid air bubbles from detaching from the walls of the caliper, the side of the piston or the inside of the brake hose - sometimes they stay around & if they’re around they are simply compressing under pressure = a soft pedal. Once you get a bit more pressure & if feeling brave, you could take to a gravel road / car park / safe space & slam your foot on the brake engaging the ABS which will pulse and help purge air if it’s in. But ideally the computer to tell it to prime / pulse is key IF air is that far up the system. Report back! Persistence is often key.

[@Preditah.]

To prevent the brake fluid from dripping, I always depress (press down) the brake pedal with a small spirit level and wedge it against the front of the seat. It's just the right size to fit against the seat and keep the pedal down (to simulate someone with their foot on the brake pedal). You can of course use a piece of wood or anything else of similar size. No mess to clean up and you don't have to worry about emptying the master cylinder.

[@SilverGoat]

Awesome video! I just bought an x5 that's the same year as yours! Thank you for showing good angles it helped so much fixing mine.

[@retromechanic2238]

Thanks for the comment! Glad I could assist 😁 best of luck with the X5!!