cruise control

[Pooh]

2000 f150, 120,000 miles, 5.4L, 4x4. cruise turns on, but wont keep speed and kicks off after losing 8-10MPH. Truck wont accelerate when pushing the accel button. The cruise is trying to work speed drops farily slow. It takes 20 seconds or so to lose 8 mph. Any ideas where I can start?

[Scott K]

I would first check the cruise deactivation switch that is screwed to the master cylinder for brake fluid leaking into it. Then unplug the cruise control servo electrical connector and look for brake fluid in the servo electrical connector.

There is a recall for this concern, it maybe covered by Ford if there is fluid coming from the deactivation switch.

[K_Josh87]

i believe there is a recall out there on this...

[Pooh]

I see no fluid leaking out of the master cylinder. Both connections are dry.

[Scott K]

Try checking for flash codes

[Scott K]

Also try cleaning the heater element on the Mass Air Flow sensor, incase it is loosing power, and not being able to hold throttle.

[Pooh]

thanks guys cleaned the MAF sensor and it came back. I put a K&N air filter in approx. 3 months ago and that probly did was the culprit.

[Scott K]

Yup, K&N filters are a big culprit to bad fuel economy because of allowing dirt through to the MAF sensor. Just think, they sell them, saying they give you more power, better fuel economy, and clean as good, or better then OEM filters.

But being a mechanic, you see the total opposite, you get to see many vehicles coming in for lack of power, poor fuel economy, and what you find is a MAF sensor that is full of dirt. Hmm... I wonder how that dirt got there? It is always the first thing I look for is the after market cleanable air filters.