Brake and Acceleration Problems!! HELP

[64mechnate]

I have a 2001 sport trac 2wd. it has 160,000 miles. I have for a month or two been having a lag in the acceleration when taking off. It will start accelerating then just fall off like its bogged down. if i let off accelleration then slam on it, it accelerates normal sometimes it takes even a couple pumps. What could this be?

And as far as the brakes go i went on a 5 hour drive to dallas let it sit for a day not having any previous brake problems and the i get in it and as im driving go to hit my brakes and the pedal sinks to the floor pretty quickly as it gets close to the floor it does catch but i wouldnt trust slamming on them. Although it i do let off it sometimes goes back to normal with a little give. Sometimes it even gets really firm for one time then i brake at the next light and it goes to the floor. Im so confused and want to figure it out. PLease help any ideas????

 

[ncranchero]

Did both of these begin at the same time? Check engine light on? Have you had the codes pulled. Sounds like maybe the booster has failed causing the bad pedal and a vacuum leak which is affecting the engine/acceleration.

 

[64mechnate]

No they didnt the acceleration problem began a while ago and has gradually gotten worse. The braking problem however began a few days ago. Is the anway i can go about checking the booster? and no the check engine light is not on

 

[Newfy Trac]

I wouldn't think it would be the brake booster or vacum line to booster. When the booster fails or line leak, pedal will be very hard to step on.

How about an ABS sensor ? When my sensor/hub started going bad, my pedal would go to the floor then catch. Try pulling fuse for ABS (under hood) and testing brakes. In a wide open area.

 

[JohnnyO]

Try some heavy duty fuel injector cleaner like BG.

 

[WidgetTrac]

The acceleration thing sounds a lot like a worn out TPS, but checking for codes is the first thimg to do on that issud.

Did you check your brake fluid? Has it ever been changed or bled?

You can unbolt the master cylinder from the booster to check for rear fluid leaking from the MC bore into the booster. Fluid can also leak past the front piston and not show up in the booster - don't know how to check for that...

Does the pedal go too far down ALWAYS, or just sometimes, or just that one time only?
When down, can you "pump it up" to a firm pedal at normal height?
If you maintain a light pressure on the pedal, will it slowly go all the way to the floor?

 

[64mechnate]

no i havent checked the brake fluid yet need to do that. And it only goes to the floor sometimes. If i pump it once or twice it goes to regular height and seems to get kinda hard too harder than normal. ANd yes i have kinda noticed that it slowly goes down if i lightly press it

 

[WidgetTrac]

Sounds like worn/hardened piston seals in the master cylinder, but i'd try changing the fluid first.

 

[64mechnate]

Today i took out the ABS fuse and the problem still occured it however got worse to the point that i push the pedal to the floor and it sticks at which point i have to pull it off the floor to get it back up. Pumping it a couple times will sometimes stiffen it up but i still dont know. Checked the master cylinder and the fluid is exactly where it is supposed to be. So should i just go ahead and pull the master cylinder or how do i check the seal? Replace the fluid first?

 

[waskly]

Today i took out the ABS fuse and the problem still occured it however got worse to the point that i push the pedal to the floor and it sticks at which point i have to pull it off the floor to get it back up. Pumping it a couple times will sometimes stiffen it up but i still dont know. Checked the master cylinder and the fluid is exactly where it is supposed to be. So should i just go ahead and pull the master cylinder or how do i check the seal? Replace the fluid first?

check for leaks no leaks put a master in it.