One problem related to transmission fluid leaking has been reported for the 2004 Ford F-150. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Ford F-150 based on all problems reported for the 2004 F-150.
2004 F-150 supercrew 2wd automatic. Transmission requires rebuild at 54000. Bought new all seals replaced within 2-3 months due to fluid leaks. Slipping began less than 40,000. Fluid flush alleviated the issue, but slipping returned. At 60 mph trasmission slipped into neutral momentarily at random times. Power rear sliding window does not work; failed within first 2-3 months; no computer code to detail the issue so Ford will not fix regardless of confirmed failure and warranty coverage. Rotors had to be replaced on first break maintenance.