[Zuk_89]

On the weekend was out 4x4ing amd loss brakes top of a massive hill (wasnt a fun ride) any one no how to fix the problem ? Gotta pump them a few times and they come back
been told there is a one way valve in the vacuum hose that can cause it but mine doesn't have one
any idea's ?

[Bosco15]

Could be a number of things that has or is failing.
Diagnose the problem by isolation of the components.
Clamp off the four brake hoses to the wheel cylinders. You will need brake hose clamps or something similar that will crimp the rubber hose without damaging it.
After the hoses are clamped, you can press the pedal and see if it holds pressure.
If it goes to the floor, then your master Cylinder is shot. If it holds pressure, then undo one wheel hose at a time.
When the pedal goes soft, you have found a dud wheel cylinder.

From what you described, it sounds like a master Cylinder problem.
If it was a wheel cylinder, only one brake circuit would be affected. You would still have two good brakes on the other circuit.

[christover1]

To diagnose a brake problem do as Bosco suggested.

[JrZook]

When was the last time you checked you brake fluid level

[atari4x4]

JrZook wrote:

When was the last time you checked you brake fluid level

this!!!!!

does you handbrake warning light on the dashboard flash at you when cornering?

[Jezza86]

Big hill could have pumped s bubble into a line giving you a spongey peddle feel and a fslse high level in the master cilinder via displacement. May be worth bleading exerything and flushing

[jdk81]

Pads worn? Or fall out?

I know sierra pads fall out when rotor and pad are low.

[JrZook]

I doubt he'd get the brakes back by "pumping them a few times" if the pads fell out somehow

[christover1]

The one way valve advice given on facebook was on the topic asking about buying a brake booster, it is not the same as brake loss advice. Booster and master are different parts. Best to get a brake shop look at it first.

[jdk81]

JrZook wrote:

I doubt he'd get the breaks back by "pumping them a few times" if the pads fell out somehow

from experience, if a pad falls out the breaks do come back by pumping a few times, but fairly suck.
It destroys the caliper and cradle etc.

[bangn]

sounds like air in the system, check fluid level.

If its dropped then check all the nipples, lines, caliper pistons/wheel cyls, pads and shoes inc brake prop valve (if it has one) for any sign of fluid

check tension on all the nipples

If all good then bleed the system from LHR, RHR, PROP VALVE (if applic), LHF, RHF.
and see if your problem stays or returns slowly. Sounds like its sucked some air in there somewhere. If issue comes back I would be looking at the brake master if no issues found elsewhere.

if the booster has shat you wont have power assisted brakes, which would mean a rock hard pedal and the brakes wont pull up as easy. It wont be a booster.

Also check the ability to be able to squeeze both front caliper pistons in, they can seize outwards on rust if pushed out enough because the pads are worn out. This would give more of a pocket to take up before you get a good pedal. Car will usually pull hard on one corner if that happens too.

[Rhinoman]

What lift do you have? some of the 3" spring lifts cause the springs to bow and push on the calipers at full lock.

[Zuk_89]

Tha ks everyone for there reply
I bleed the brakes I got a nit of padel but I gotta pump them about 3 times then I got full pedal anyone no whats wrong ?been told that the near brakes may not be adjusting to where they should be ?