Hi. I have 1994 f150 with a 300 straight six. having troubles with brakes. when driving i either have no brakes or all brakes where the tires just lock up. i have bled and bled the brakes but still doesn't seem to improve. everytime i bleed the brakes there is always air in the lines. but brake fluid is not going down and not leaking anywhere that i can see. not to sure how to fix. any ideas?

 

Welcome to the forum! I'd begin with master cylinder replacement (or repair kit, though new part is always better). I'm not sure how the air gets into the system. If air is "distributed" to all wheels - master cylinder seems a good starting point.

 

thanks for the reply

 

Do you have a 'low' pedal feel?

Sometimes brake & clutch mater cylinders like to fail in a half working type of way - basically the cylinder only pushes half way making it seem like you need to bleed the system.

Start with the massa cylinder - easy enough to do!

 

well when pushing on the brakes there will be no pressure until i hit the floor but by then my tires will have locked up by then.

 

Sounds like you definitely have air in the system. Starting with the right rear. Bleed that caliper or wheel cylinder until NO air is present or visible. Sometimes tapping the caliper or wheel cylinder helps any air bubbles move towards the bleeder valve, and escape. After that wheel is bled, move over to the Left rear, then the right front. Finishing with the left front.
The idea is to start the bleeding process at the wheel furthest from the master Cylinder, finishing with the wheel closest. It sometimes also helps to raise the rear axle higher than the M/C to get the air to move towards the highest point.

If this doesn't seem to help, then move onto replacing the Master Cylinder.

Hope this helps.

Keith
km@frozenrotors.com

1.888.323.8456
952.746.8880
www.frozenrotors.com