Brake issue

[Papabear]

front pads look good haven't had the rear wheels off to check the shoes (i know better but see you, know evil hear no evil see no evil) the brakes feel like i have no vacuum (power brakes) but i puuled the line from the vac pump and i have good vacuum. on the first brake application i have really good brakes and if i back off and re-apply or pump them they suck ( like only 60% stopping power) i have no obvious brake fluid leaks.

 

[hoodshauler]

could be a bad brake booster.

 

[Papabear]

i really hope not how do i diagnose it?

 

[69dieselfreak]

my buddys 89 crew cab 7.3 turbo f-350 single wheel 5spd
would do that at the worst times during rush hour traffic and that truck is ***** to stop suddenly we were driving somewhere in phx and almost got into a accident a couple of times
being poor colledge students that we were it finilly got fixed like 6 months later it was the vacume booster
i think we spend most of that moeny on beer and partying it was fun though that was five or six years ago

 

[hoodshauler]

i really hope not how do i diagnose it?

If you have access to a vacumme pump and a gauge. Pull a vacumme on the booster and see if it leaks down. I think that will work someone with more knowledge help me out here Please.

 

[69dieselfreak]

if it does end up being a vacume booster now is a good time to do the switch to hydro boost

 

[JPR]

how long does it take for the brake light to clear after the engine starts? This is a good indication of capacity (volume) of vacuum pump.

 

[Papabear]

how long does it take for the brake light to clear after the engine starts? This is a good indication of capacity (volume) of vacuum pump.

you mean the e-brake light? if so it is always on because my wife put the e-brake on last summer and drove away without taking it off and it has stayed on ever since