Bruno2 Posted September 7, 2019 Share Posted September 7, 2019 I jumped in the boy's 91 F 150 the other day to run down to the store. Pulled up to the stop sign at the neighborhood entrance, hit the brakes and the pedal went straight to the floor! My son Kristopher casually mentions that it has been doing that for a couple of months. Said he slides into intersections when it rains... . Time for a brake hydraulic lesson to say the least. I get to the store by the grace of God and pop the hood to have a look around. The paint is all blistered off of the booster and it's corroded down below it. Looks like a master cylinder. I pull up Amazon and Rockauto to shop. They have OEM for about $65 which I was thinking was good, but I really like Wagner brake stuff. There is nothing wrong with Motorcraft and that probably was the original with 215k and almost 30 yrs of service that was on it. However, the Wagner was $30 including Prime shipping so I went with it. I call the boy this morning to tell him to meet me at the shop. We have brake work to do. I show him how to bench bleed a master cylinder as well as explain why we are doing this. I let him install the bleeder kit. He does and the bench bleeding gets under way. Soon after a few strokes I notice one of the fittings is leaking some. He tightens it and I explain that is was probably sucking air back in the entire time it was leaking. So we are back to square one. Bench bleeding continues. Finally he says no more air is coming out. I reply good, give her another 10 strokes for good measure. I get him tooled up for the removal. I explain what little bit of inside info I have about removing brake lines or bleeder screws. Anything metal that has had extensive contact with brake fluid is usually corroded and seized in place. So you get the correct flare nut wrench of quality that fits the flare nut. These parts are not to be patty caked or candy assed around with. When you get ready to break it loose you GO and GO HARD! Anything less will typically result in rounded off flare nuts or a steel line wrapped around the inside and twisted up. So he does . The removal was successful. He does the reinstall with no problems. I show him how to manipulate the lines with one hand so the flare nut threads in easy with the other hand. Now it's time to bleed the system. I have a mighty vac, but I wanted to go old school with him by using the two man system for bleeding to help him understand what we were doing and why. I have been told that when bleeding an ABS vehicle that the proper place to start is close to the MC and work away from it. I have always used the same pattern I was taught though. I start as far away as I can get and work to it. I have done that on multiple ABS vehicles and never had any issues. So off we goooo. I started by showing him how open the bleed screws(also informed him they were not grease fittings and not to try to grease them:nabble_smiley_tongue:) in order to be sure they would open and were not obstructed. This is a gravity bleed technique that not only checks for flow, but purges out the old dirty brake fluid. He tightens the bleeders back up and I tell him to get in the driver's seat. When I tell you so pump the pedal and hold it down. I will open the bleeder and the pedal will fall. DO NOT let up on the pedal before I say so because I have to close the bleeder or it will suck air back in and we will be back to starting from scratch. We start "pump it up, hold it down. Up, pump it up hold it down (repeat until no more air is visible and fluid is no longer milky looking. I also informed him his job as the pedal operator was to keep tabs on the MC reservoir so it doesnt run dry and introduce air into the system again. It was a successful MC swap and a good educational experience for him. Link to comment Share on other sites More sharing options...
Gary Lewis Posted September 7, 2019 Share Posted September 7, 2019 Well done! But does it stop? Link to comment Share on other sites More sharing options...
Bruno2 Posted September 7, 2019 Author Share Posted September 7, 2019 Well done! But does it stop? It stops really well now. The brakes do not lock up in an emergency stop situation either. I forgot to mention above that I also showed him how to do a brake inspection on the front. I used a new set of pads on the shelf at the shop to show him how they have a separation in them to show wear depth. I pointed out the opening on the caliper where a visual inspection could be done. He looked at both sides. I mentioned to him that he needs to pay attention also to see if both sides were wearing even. Uneven wear from one side to the other is indicative of caliper issues. While we were test driving it after the repair I pointed out that pulling one way or the other when braking is indicative of a caliper problem as well. Link to comment Share on other sites More sharing options...
Gary Lewis Posted September 7, 2019 Share Posted September 7, 2019 It stops really well now. The brakes do not lock up in an emergency stop situation either. I forgot to mention above that I also showed him how to do a brake inspection on the front. I used a new set of pads on the shelf at the shop to show him how they have a separation in them to show wear depth. I pointed out the opening on the caliper where a visual inspection could be done. He looked at both sides. I mentioned to him that he needs to pay attention also to see if both sides were wearing even. Uneven wear from one side to the other is indicative of caliper issues. While we were test driving it after the repair I pointed out that pulling one way or the other when braking is indicative of a caliper problem as well. Good! Well done! Link to comment Share on other sites More sharing options...
Bruno2 Posted September 7, 2019 Author Share Posted September 7, 2019 It stops really well now. The brakes do not lock up in an emergency stop situation either. I forgot to mention above that I also showed him how to do a brake inspection on the front. I used a new set of pads on the shelf at the shop to show him how they have a separation in them to show wear depth. I pointed out the opening on the caliper where a visual inspection could be done. He looked at both sides. I mentioned to him that he needs to pay attention also to see if both sides were wearing even. Uneven wear from one side to the other is indicative of caliper issues. While we were test driving it after the repair I pointed out that pulling one way or the other when braking is indicative of a caliper problem as well. It was hot so we stopped there. I wanted to show him how to inspect the drums and adjust them. Maybe tomorrow morning... Link to comment Share on other sites More sharing options...
Bruno2 Posted September 7, 2019 Author Share Posted September 7, 2019 It was hot so we stopped there. I wanted to show him how to inspect the drums and adjust them. Maybe tomorrow morning... I need to do front brakes on Whitey the 96 F250. We may do those so he can see how that's done and then inspect his drums. Link to comment Share on other sites More sharing options...
Gary Lewis Posted September 7, 2019 Share Posted September 7, 2019 I need to do front brakes on Whitey the 96 F250. We may do those so he can see how that's done and then inspect his drums. That would be a good project to teach him on. Link to comment Share on other sites More sharing options...
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