Posted by Caleb in Kansas [172.68.34.7] on Monday, January 02, 2017 at 23:09:14 :
Got a neighbor with a 96 F350 4x4 Powerstroke 5 speed truck, 78,000 miles. Early this summer he was having problems with a soft pedal and some air intrusion in the rear brakes. We replaced both rear wheel cylinders and bled everything since one was found to be leaking slightly and the problem went away for awhile. After that while, he found out that he was still having issues when he went to stop hauling his trailer with his large JD skid loader, bucket, pallet forks, 200 gal water tank, and Gator in tow....front brakes locked (quasai...the abs was working as well as 90s ford front abs works) rears apparently did nothing and luckily his trailer brakes were able to get him stopped. This was not an emergency stop, just a normal stop on an off ramp. After that, we bled the brakes again and found some air. Back to normal. About 2 or 3 days later, he jumped in and the pedal went right to the floor. Bled again and found air so we cracked the rears, and started lettimg them drain through clear hose and the plastic nipples so we could kind of see air. 2 bottles of fluid, and sevwral beers later, no air. Brakes worked great. For 2 days. The next time, we got a bunch of air right off the bat...said screw it, and warrantied the new wheel cylinders. 2 more days, more air...chased all the lines and found no sign of leaking. Kinda ticked, we successively did the following: new master cyl, properly bench bled according to manufacturers instructions, new abs module on the frame rail below the MC, finally, new rear rubber line. It was fine for about a month, then right back to square 1. He took it to the shop where they hooked up their fancy bleeder and pulled air out, checked over "everything" and sent the truck out. A couple days later and same thing. Back to the shop. They kept it a couple of days to try and recreate the problem, which they did. Now saying its a bad vac booster....how would that explain air in the lines? Is it pulling a vaccuum on the MC which in turn is pulling suction on the rear cylinders and drawing in air? Another symptom that has started up is that the pedal will continue to fall slowly to the floor under pressure.....im at a bit of a loss on thia one.
Dodge Content: He just picked up a new 16 Ram 3500.
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