I have a 1992 F150 with just short of 300000 miles on it. In the last 3-4 months the brake fluid has been disappearing. I looked under the truck , lots of oil but no brake fluid. If it is entering the booster where is it going from there? Will it get sucked into the motor? I have put 4-5 quarts in the tank in this time now its needing it every week. If it is entering the booster do I have to change the Master cylinder and the booster or just the booster ? Sorry for the long post . Thanks Scott

 

Sure a line or bleeding screw isn't loose and is just leaking a bit here and there? Same thing just recently happened on my truck.

 

Are you constantly having to top it off? If not, is it possible that your pads are low, in turn making your fluid level low?

 

All that oil you see under there could in fact be brake fluid too. You have to degrease everything, then look for fresh leaks. You probably have a cracked line or a leaking seal somewhere.

 

Rotty brake lines are not uncommon, espically on your 16 year old truck. Park the truck somewhere fresh, without oil stains there, and observe where it's dripping. But first, get under there with degreaser spray and a rag, and clean everything off.

Once you know the general area of the leak, clean it off again and get that white foot powder spray. Coat the suspect area with it, and the exact leaking spot will be obvious.

Brake issues are not a place you want to dink around with duct-tape and band-aid fixes. If something's up, fix it right ASAP. My brakes gave out on me resulting in a rear-end, with over $1500 damage to the minivan I hit, and it could have been much worse.

I'd be surprised if the fluid was making it's way into the motor, but you can pull off the vacuum booster line and look. It it wet inside? Shouldn't be.