BFR

Now that I know how to replace the brake pads, I need help with another brake problem. The power brake servo is, I believe, hydraulic as opposed to vacuum operated. Truck now has 165,000 miles on it and some years ago and maybe 75,000 miles ago, I noticed a grease/oil stain on the carpet beneath the accelerator pedal. I believe it comes from the power brake servo unit mounted on the firewall. The unit is all greasy although not "shiny wet". The brakes work fine and always have. Has anyone else run into this problem and how hard is it to fix? Also, where does the oil come from to power the unit or is it sealed? It looks like it has an accumulator - a 3"-4" long cylinder perhaps 1-1/4" in diameter at about 8:00 o'clock on the unit (viewed from the front of the truck looking toward the rear), so maybe the unit is sealed and will eventually quit working, when the fluid gets low enough that the accumulator doesn't work anymore.

How complicated is replacement? Do I just buy the part and bolt it on or does it involve opening the brake system, re-bleeding, etc.?

Thanks, all.

BFR

lukemoore646

that is called hydroboost, it uses the powersteering pum to provide pressure for the brake system, it came out in the diesels for an alternative to vacuum assist and it works very well, the parts as far as i know just bolt on, you can probably unbolt the master cylinder from the booster and bend it out of the way with the lines still attached, but with that many miles it is probably time to change your brake fluid anyway (it probably isn't clear anymore is it?), you shouldn't have any problems doing it yourself but i have been wrong before...