Loost brakes! ABS light on.
#1
Loost brakes! ABS light on.
I recently purchased a 1997 f150 4x4 with ABS. When I was driving it one day at about 10 MPH (thankfully) I went to slow down at a stop sign and my brake petal was ROCK SOLID. It didn't budge. I kinda freaked and tromped on the e brake. Well even at only 10 MPH I skid my rears for about 10 feet. Then the ABS light cam on and I THINK I heard a single clunk noise like a big relay or valve moving. I carefully drove it home but as I suspected because of the ABS light being on it drove fine. The light has not gone out since.
What would cause this? It seems dangerous to have a component in a brake system that could stop the brake pressure from being delivered to the calipers if there is an electronic failure.
Thank you
What would cause this? It seems dangerous to have a component in a brake system that could stop the brake pressure from being delivered to the calipers if there is an electronic failure.
Thank you
#3
#4
I imagine you have it fixed by now... but just in case...
Its not air in the brake lines, that would indeed cause spongy brakes / long pedal travel.
This is very likely a vacuum booster problem. Hopefully just an issue with the vacuum hose and not the booster itself. Start by checking the hose for any holes/cuts. If you do not have any boost, the brake pedal will be very very hard.
To see what this feels like on a good system, shut off your engine and pump the brake pedal about 5 times to deplete the vacuum in the booster - you will barely be able to move the pedal. There are government regulations on un-boosted stopping distance that are taken into account when designing vehicles. This ensures that you have some degree of safety if the booster fails. But its still a big difference from the normal brake pedal feel.
Its not air in the brake lines, that would indeed cause spongy brakes / long pedal travel.
This is very likely a vacuum booster problem. Hopefully just an issue with the vacuum hose and not the booster itself. Start by checking the hose for any holes/cuts. If you do not have any boost, the brake pedal will be very very hard.
To see what this feels like on a good system, shut off your engine and pump the brake pedal about 5 times to deplete the vacuum in the booster - you will barely be able to move the pedal. There are government regulations on un-boosted stopping distance that are taken into account when designing vehicles. This ensures that you have some degree of safety if the booster fails. But its still a big difference from the normal brake pedal feel.