Brake issues on 96 Z-71 Need some professional advice

[Christopher Quast]

My dad and I bled all the brakes starting on the right rear and worked our way forward and I put new brakes on within the last year and barely drive it and the other day I was using it and the pedal goes way down and I don't have [PoorWordUsage] for stopping power at all. I was kinda thinkin the master cylinder is going bad or the booster Does it sound like I'm on the right track here and if not please point me in the right direction.

[Jeremy airjer W]

You need to pull the wheels and see if anything is leaking like a rear wheel cylinder. Typically a master will have a slow pedal drop when they fail. A failed wheel cylinder, brake line or brake hose will cause the pedal to drop immediately.

[Scott K]

Is it possible the rotors and drums are rusty from sitting and you just need to apply more pressure on the pedal because of the rust?

[Christopher Quast]

Thanks guys Air I will check the obvious first and 4wandering is this a common problem or just something you've personally experienced I know last fall when I had them off I cleaned up the drums and checked everything over good before I took it to Colorado and I had the truck loaded to the max and was pulling a trailer with the 3 wheelers we took along and even coming down the switchbacks I had no problems ever with my brakes and I looked and no obvious leaks and if I pump them fast they will build pressure and then it's gone right away again. Got me stumped!!!

[Scott K]

If you can pump it up, I would make sure rear drums are adjusted up then bleed air out of sytem.

[Christopher Quast]

The other night I thought just for kicks I would check my fluid level and I took the cap off the resivoir and what I found just floored me. The diaphram or gasket apparently grew approx 1" and it was laying down inside under the brake fluid and it's no wonder I had bad brake pressure.

But what would cause something like this to happen did it get really hot and expand last year out in the mountains or is this a sign of other problems in the future?

[Jeremy airjer W]

Somebody added power steering fluid instead of brake fluid. If the pedal went to the floor than you have been driving it long enough to possible ruin other components. Brake hoses, calipers, and wheel cylinders. The Power steering fluid will do the same thing to the seals in these components that it did to the seal on the cap. If you catch it right away typically the system can be flushed and a new seal for the cap and everything is good to go. In your case you will likely be looking at complete hydraulic component replacement (everything except the metal lines) and a thorough flushing of the metal lines.

[Splake]

Was the brake fluid low? These trucks have problems with brake line corrosion along the frame over the gas tank where dirt,salt and moisture collect.

Splake

[Jeremy airjer W]

If the seal on the cap for the reservoir is bloated than something other than brake fluid was added to the master reservoir! I see this about 2-3 times a year.

[Macgyver55]

We had this happen to several new vehicles we had delivered some years ago. Since the fluid was only added to the master cylinder and never really worked its way down into the rest of the system to contaminate other parts, we were able to replace only the master cylinder and then pressure bleed the system to get rid of the residual fluid. We never had any further problem with any of them.

[Christopher Quast]

In your case you will likely be looking at complete hydraulic component replacement (everything except the metal lines) and a thorough flushing of the metal lines.

Airjer first off I have never had to flush a complete system before. What are the steps I will need to take in order to acheive this goal properly? And secondly shouldn't I be fine if I just keep an eye on my fluid level and also check my components on a regular basis instead of just getting GUNG HO and replacing everything right off the get go???