Bleeding F150 Brakes

1 Dollar · Jul 31, 2011

I put new front lines, rotors, calipers and pads on my 1999 F150 due to rust and wear last week and after bleeding three times and some short trip driving I cannot seem to get them bled completely. On dry pavement I cannot get enough pressure to kick the ABS on, but it does stop in a hurry.

I've been the one under the truck each time and I've had my helper put pressure on the pedal, I cracked the bleeder open with a clear tube attached, watched the flow for bubbles, then closed the bleeder before the flow stopped to avoid sucking in air there. Then repeat this till I see no bubbles.

I have only been doing the two front lines since I didn't open up the rear, should I do all four each time? The reservoir got pretty low as I was replacing the lines. Any other ideas on getting it back where it should be? In "normal" stopping it feels fine and not squishy, just can't get a whole lot of pressure past that.

Thanks

shawnspeed3 · Jul 31, 2011

Most modern vehicles W/ABS require the use of a code scanner/diagnostic tool to pump the air out of the ABS unit...most cannot be bled in a conventonal manner...consult a sevice manual for bleeding procedure..Shawn

john_Bud · Aug 1, 2011

Probably the ABS system has bubbles in it.

I am not looking forward to the day I have to tackle it.

Hurst · Aug 2, 2011

Does it sink down if you apply a certain amount of pressure? If so, let it keep sinking and see if it gets to a point where it will build up pressure. You can do it while it's stopped. My Dad's 03 does this and it's a bad valve in the ABS module that causes it. Brakes work fine otherwise, just kind of scares someone who jumps in and drives it having never driven it before lol. It almost feels like a bad mastercylinder for a little bit, then catches again lower to the floor (we put in a new master cylinder thinking that was the problem... nothing changed).

Hurst

1 Dollar · Aug 3, 2011

Put on four "Speed Bleeders" and bled it again myself, and got an air bubble from both fronts. Seems to work well now, and the pedal hits hard before it gets to the bottom. Actuated the ABS on a gravel road too.

Check out those speed bleeders if you like quick, cheap and effective products!

kossuth · Aug 16, 2011

I've had this happen on an S10 pickup I owned. Air can get into the ABS unit. There are two ways you can try to get the air out. I made a special adaptor for the master cylinder cap to attach a mitty vac to. Filled the master about 3/4 full of fluid (vacuum draw has to be above the fluid thus why 3/4 full. You want it to pull the excess air vs fluid) and put a good vacuum on the system. I then pumped the brakes to see if I could get the air out. Don't be alarmed if the pedal goes to floor, it's pulling the fluid up to the master (and hopefully the air) out and into the mitty vac catch can. If the air is in the front half of the ABS this probiably will get it. If it's down in the vain assembly good luck! You're gonna need to get the proper scan tool and follow the factory procedures to bleed that bad boy if it was like my S10.

Bleeding F150 Brakes

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