2002 Ford Excursion 7.3 Diesel. Driving along and some D&%k pulls in front of me and slams his brakes. I slam mine and pop peddle to the floor and just barely stop. Limp it to work and then back home again. I know bad idea.

Inspect for leaks and find fluid from right rear calliper. It is crushed like rocks never have I seen a piston fail like this.

So I order up the power stop kit from Rock. I put them on the front last year and they have been awesome. Vented drilled slotted rotors, ceramic pads, new callipers and brackets. Change everything over and start the bleeding. And more bleeding and more bleeding. Bleeding furthest from master cylinder to closest. Yes i'm bleeding properly not my first rodeo.

Brakes grab, I slow down, and then peddle sinks to floor where I still have stopping, just peddle to the floor. Peddle is easy to push have power assistance for sure. Everyone and there dog says you blew the master cylinder. During my full 10th or 12th inspection nothing is leaking from behind. Oh well replace the Master cylinder brand spanking new. I knew driving that I could wreck the master.

I bench bleed the master cylinder for at least a half an hour using short strokes. I mean there is absolutely no way there is any air left. the fluid is flowing perfect no air. Install master cylinder and the brake light is on now. Wasn't on before. Think Maybe a broke a wire when screwing in the sensor. Does anyone know which harness is for the brake light??? drivers side or passenger side master cylinder??

Bleed bleed and more bleed. The peddle is exactly the same. Drive it for a bit and bleed again. And again.

So if you made it this far THANK YOU for staying with me lol.

Power steering is great, wifey easy to turn at a stand still lol. No fluid leaks in the hoses running from the power steering pump to the hydro boost area. When the brakes are pushed I can see the hose move though no sure if thats normal? Brakes grab about half peddle then slowly sink to the floor. The peddle comes back up slow too.

Now I have done a lot of reading about hydro boost vs vacuum brake boosters. I'm guessing that the two systems are very different and have very different symptoms, which leads to a lot of mis diagnoses like people saying no your peddle would be hard to push its not your booster.

Is there anything else I should check or do before I drop $200 on a hydro boost unit? and what are the recommendations for new vs old. I mean at this point my brake system is dam near all new already lol.

Sorry for the lengthy post but wanted to include everything I could for everyones consideration. Luckily its Mustang season and I have had time to let the truck sit. However cabin season is coming fast lol.

 

Crushed

 

Little brake ****. This is the power stop kit from Rock