hopakco

Last week the break pedal seemed to develop more travel then normal. The rotors and pads were due for a change so did that and bled the lines. There was a ton of air in the passenger side front. Had a real hard time getting rid of the air but finally got it out, I think. Still a lot of travel but improved. On a hard stop goes to within an inch of the floor.
Is this normal or could there be air in the system still?

1997,1500 off road 4x4, auto short bed and cab

Mike Sigmond

I bet there is still air in the lines somewhere. You topped the fluid off after bleeding it right?

RPegram

Since your soft more travel than before problem existed before replacing front brakes, I would say you probably have another problem. I would start looking at the master cylinder. I have seen these allow air in when going bad (actually gone). Also see if you can pump the pedal several times very quickly and see if you get more pedal. If this happens then you either have air in lines or check rear shoes and check for wear/adjustment. If pumping makes no difference or if it does and pedal slowly goes down with steady pressure, then I would look at master cylinder first. If pedal stays up then I would look at air in lines/rear out of adjustment or wore out. Also make sure rear drums are not wore out. I have seen mud eat out drums in 2 months.

hopakco

Yes pedal stays hard if I pump it. Before I start up the pedal is hard, as soon as I start up
the pedal drops down a couple of inches; and yes if I pump it it'll firm up. So probably air?

therewolf

Call around and see if you can find a shop with a power bleeder. Set up an appointment.

It's the best mistake you'll never make.

RPegram

The pedal dropping a little upon starting is normal. It is just the booster getting vacuum and doing its job. I would check the rear for adjustment. If they are out of adjustment, it will cause a low pedal. If your unsure about getting the air out, hit ALL 4 wheels again. Start at the wheel the fartherest away from master cylinder and work your way toward the cylinder. Since you can pump pedal and get it to come up and stay up, you have probably ruled out the master cylinder. Since you run in mud, it will cause problems on rear brakes.

bioDAWG

Not trying to hi-jack this post but I have a similar problem. If I pump the bake pedal with the engine off it will get hard and then when I start the engine the pedal will drop to the floor. I have bleed all of the lines and I am currently on my second master cylinder.

One thing that I have noticed about my MC is if i press the pedal with the fluid cap off the MC with spray fluid out for the reservoir in a steady stream. Is this normal or does this mean that I have something else wrong?

By the way I have a 97 K1500 Z71.

RPegram

bioDAWG, It sounds like you still have a lot of air in system. Did you bench bleed master cylinder before installing? It is much easier to bleed this before installing. If not, bleed that well, then go to fartherest wheel from cylinder and start bleeding brakes. It will take a lot of bleeding to get all the air out. When you bleed the brakes, crack open bleeder screw and tighten back before the pedal reaches the floor. Also keep an eye on the fluid level. It can drop very quickly especially when doing the front. Also, don't get any of that fluid on any painted surfaces. It will take paint off faster than paint remover.

zenash22

My friend has a 1992 chevy 1500-it started with the brake lite coming on-he bought a new master cylinder, rotors, pads, drums etc....-bled everything-lite come on still and pedal slowly goes to the floor at a stop-read somewhere to bypass the dump valve-did this-pedal a little better but still alot of travel in the pedal? please does someone know how to fix this????? or what it is
THANKS!
Annie

Allislandwood

done every thing on this forum and nothing changed going to do all the check valves and abs system this will not beat me