Diagnosing a brake problem...?

[OrngK5]

Hey, calling on all you K5 gurus out there again, an issue has come up with my brakes or braking system. I have to push the brake pedal to the floor for it to generate any braking power, and hard too. This happens while running or while turned off. There is no air release at all after any pumps on the pedal, and no back pressure, the pedal just goes straight to the floor and immediately back up. I have not touched any part of the braking system whatsoever other than checking the reservoir fluid level, and it appears fine.

Has my master cylinder gone bad? There are no leaks around the inner wheels, or any fluid leaks from the lines leading away from the reservoir. Thanks in advance for any help!! I searched earlier, but all the problems from other members developed after replacing the MC or bleeding the brake lines, which I have done neither.

 

[stoney126]

what year is your truck? gas or diesel?

 

[OrngK5]

400ci gas 1978' 1/2 ton 4wd

 

[YZEATER]

have you adjusted your rear drum brakes properly?

 

[OrngK5]

have you adjusted your rear drum brakes properly?

I haven't touched, modified, or done any adjustments to it since I purchased it last October. It was serviced earlier this year and it got a fairly clean bill of health, this problem developed a couple of days ago.

 

[YZEATER]

maybe that's where you should start.

 

[OrngK5]

maybe that's where you should start.

That seems pretty vague, are you suspecting the problem is at the brakes themselves? Would that explain the lack of back pressure from the pedal?

 

[YZEATER]

i would try to adjust the rear brakes. crawl underneath and use the adjusters to tighten up the shoes if they need it. while your under there look for brake fluid leaks. you gotta start somewhere. if they are not adjusted properly, they will take more fluid, explaining you having to push the pedal further to the floor.

 

[OrngK5]

i would try to adjust the rear brakes. crawl underneath and use the adjusters to tighten up the shoes if they need it. while your under there look for brake fluid leaks. you gotta start somewhere. if they are not adjusted properly, they will take more fluid, explaining you having to push the pedal further to the floor.

Thanks for the help, I took a look in the 15lbs manual that I have, its no Haynes guide but it is very detailed. It lists air in brake system as the most probable cause for excessive travel, following the self adjusters may not be operating properly either. I'll look for fluid leaks, the only ones that are very apparent are the usual motor oil leaks.

Sometimes I wish I had a lift in my garage

 

[stoney126]

Sometimes I wish I had a lift in my garage [/quote]


i wish for that all the time