Brake booster leaking

[280Z Turbo]

I just recently started to notice that my brake booster was leaking vacuum. I can hear a constant hissing from underneeth the dash, but it goes away when I push the brakes.

I still have power brakes, but when I shut off the engine and coasted into the driveway today, I had no power brakes. Before, it would always give me one power brake use with the engine off.

So, do I need to replace the whole booster, or could this be something else.

[footoflead]

If you want to go the expensive route just replace the booster and problem solved...and hoses??

If you want to go the cheap-o route you'll have to track down where the leak is coming from....Happy Hunting :)  

[280Z Turbo]

Expensive? No, I wouldn't buy a new part for that truck, it isn't worth it.

That's what junkyards are for.

[Run Away]

JB Weld!

[280Z Turbo]

JB Weld!

That's what keeps the oil in my oil pan! Good stuff!

[BartsSVO]

Hmm...if its cutting off the vaccum when you push the pedal (which it is supposed to do) then its probably something internal leaking. Time for a new or junkyard booster.

[280Z Turbo]

New costs $70 at my uncle's Carquest store. We haven't checked at U-Wrench-It yet.

[Run Away]

I just figured out my master is going.

Stand on the brakes for 5 seconds, and the pedal hit the floor.

[BartsSVO]

I just figured out my master is going.

Stand on the brakes for 5 seconds, and the pedal hit the floor.

Make sure you bench bleed the new one before installing it. It will be next to impossible to bleed the brakes if there is any air trapped in the MC.

Oh, get a proper flare nut wrench as well. For occasional use the ones at Pep Boys seem to be well made.  

[Run Away]

Thanks for the tips, I'll be sure to do that. :)

Is the bench bleeding still required if I pull the master from a car with a perfectly functioning vehical (ie the master is full of fluid)

[BartsSVO]

Thanks for the tips, I'll be sure to do that. :)

Is the bench bleeding still required if I pull the master from a car with a perfectly functioning vehical (ie the master is full of fluid)

Usually you shouldn't as long as you pull it from the donor vehicle and install it within an hour or two. Personally I would drain the fluid from the donor master cylinder and spray it out with some brake cleaner just to make sure there isn't any crud trapped in there. If the fluid is more than a couple of years old it probably needs to be drained out. I'm sure you probably know that brake fluid readily absorbs moisture in the air, which can lead to corrosion of components in the brake system. Along with heat, the small particles of iron and aluminum oxide are what discolors brake fluid.

Bench bleeding isn't that difficult. Just go to your local parts store and pick up a bench bleed kit. It consists of two hoses and an assortment of little threaded adapters. You put the adapters into the ports on the master cylinder and then loop the hoses back into the reservoir. Fill the reservoir about halfway (just to keep from making a mess) and pump the MC with a screwdriver about 1-1.5". When it gets hard to pump the MC, you're done. It shouldn't take more than about 5 minutes.