Mechanics

SOFT BRAKE PEDAL

1998 Ford Windstar

Brakes problem
1998 Ford Windstar 6 cyl Front Wheel Drive Automatic 144 00 miles

I have a 98 windstar with 144 000 kms on it. The problem I am having is that the brake pedal keeps going down to the floor very slowly. Lots of brakes, but the pedal goes all the way down. We changed master cylinder, front and rear brakes are all good, and no leaks. Also, no brake light or abs light, once in a while the trac light will start flashing while im driving, but is not on when I re start it. Could this be a problem with the ABS unit?
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Pweb
December 20, 2008.



MASTER CYLINDER
Changes in brake pedal feel or travel signal something could be wrong in brake system. When diagnosing brake system problems, use brake warning light, pedal feel/travel and fluid level as indicators. Following symptoms indicate brake trouble: Pedal goes down fast: Check for leaks or air in system.
Pedal goes down slowly: Check for external or internal leaks.
Pedal is low and/or feels spongy: Check for empty master cylinder reservoir, reservoir cap vent holes clogged, rear brakes out of adjustment or air in system.
Pedal effort too high: Check for binding or obstruction in pedal linkage. Check for poor booster assist.
Brake warning light is on: Check for low fluid level, ignition wires too close to fluid level indicator assembly, damaged indicator float, low vacuum (diesel) or applied parking brake.
HYDRO-BOOST UNIT
Use following list of symptoms to aid in diagnosing Hydro-Boost problems: Brake pedal returns slowly: Check for restriction in return line between Hydro-Boost and power steering reservoir.
Check for incorrectly connected return line.
Reposition brake pedal or add return spring.
Replace Hydro-Boost.
Brakes grab: Tighten power steering belt.
Flush steering system while pumping brake pedal.
Replace Hydro-Boost.
Hydro-Boost chatter/Pedal vibration: Tighten power steering belt.
Check for low fluid level.
Accumulator leaks down/No reserve brake application: Replace Hydro-Boost.
High brake pedal effort: Tighten or replace power steering belt.
Low fluid level.
Replace Hydro-Boost.
Brakes apply by themselves: Restriction in return line.
Return line not connected correctly.
Replace Hydro-Boost.
TESTING
POWER BRAKE FUNCTION TEST
With engine stopped, remove vacuum in system by pumping brake pedal several times. Push pedal down as far as it will go. If pedal moves downward slowly, hydraulic system is leaking. Check hydraulic system for leaks.
With pedal pushed down as far as it will go, start engine. If pedal moves downward, vacuum system is okay. If pedal does not change position, a problem exists in vacuum system. Check vacuum system for leaks.
MASTER CYLINDER
To check master cylinder for internal leak, disconnect brake lines at master cylinder. Plug outlet ports of master cylinder. Apply brakes. If pedal height cannot be maintained, master cylinder has internal leak and must be rebuilt or replaced.
BRAKE WARNING LIGHT
Brake warning light should only come on when ignition switch is in START position or when ignition is on with parking brake applied or fluid level low. On diesel vehicles, brake warning light should also come on when vacuum is low.
If brake warning light does not come on when brake fluid is low, manually push reservoir float to bottom of reservoir. If light still does not come on, check fuse, wiring and bulb. Repair as necessary. If bulb and related circuitry are okay, replace reservoir assembly.
If brake warning light does not come on when parking brake is applied, check parking brake switch, wiring and bulb. Repair as necessary. With parking brake released and master cylinder reservoir full, turn ignition on. If warning light is on, check for shorted, grounded or defective warning switches or wiring. Repair as necessary. Turn ignition switch to START position. If brake warning light does not come on as a bulb check function, check fuse, bulb and wiring. Repair as necessary.
BRAKE PEDAL RESERVE
If brake pedal is low or bottoming out, run engine at idle with transmission in Park or Neutral. Lightly depress brake pedal 3 or 4 times. Wait 15 seconds for vacuum to build in booster. Depress brake pedal until it stops moving downward.
While holding pedal down, increase engine speed to about 2000 RPM. Release accelerator pedal. Brake pedal should move downward as engine speed returns to idle. If results are correct, system has proper pedal reserve. If results are not correct, check for adequate vacuum. If vacuum is okay, replace vacuum booster.

Dave H
Dec 20, 2008.
Thanx for the info, but this vechicle is already at a garage with qualified techs and they have tried all that. Still cannot figure out the problem.

Tiny
Pweb
Dec 20, 2008.
You might want to look in the windstar section of this forum

Posted at Mon Jul 23, 2007 9: 47 pm
By frenchbull, Likes cars!
Give Feedback | Votes: 0

I had the front pads replaced and rotors resurfaced and rear brakes serviced. And at the same time the ABS and red brake warning light came on. The mechanic was dumbfounded said he didn't do anything to make that problem occurr. He changed the pads and the problem seemed corrected. Approx. 200 miles later. The brakes were applied hard, and soon after, the lights came back on intermittently. Seems like the lights come on quickly when the car is hot and been driven a while. If the car is cold or has sat overnight, the lights don't come on. Took it to the dealer, they ran a diagnostic ($100) said it needed a new ECU ($700). Don't mind paying if that's what it really needs, but it just seems like the problem occurred when the pads were replaced and maybe the original mechanic bent or tore something. The dealer is adamant that the C1185 code would not be affected by anything the original mechanic did (replacing the front brakes, resurfacing the rotors and rear brake service). I feel backed into a corner. Your thoughts.

Find a car repair manual for your Ford Windstar Repair Question.

Dave H
Dec 20, 2008.