hydroboost brake light

[K5dreamer]

hey all, ive been having a kind of annoying situation on my truck, where if i apply more than a gentle pressure on the brake pedal, the brake light comes on. if im soft on the pedal and gradually slow the truck down, the light dosnt come on, but if i have to stop quick, or even when the truck is at high idle durring warmup, pressing the pedal hard enough to keep the truck stationary will turn the light on.

I had thought it was because i completely redid my front brakes, and havent done the rears yet, and the proportioning valve was sensing the difference and setting off the light, and had even thought i had a leak at my rear brakes, but i dont seem to be loosing fluid. Doing some research i was reminded that the hydroboost operates off the power steering. well, i recently saw my power steering was wayyyyy low, and the steering was sloppy, and i topped off my fluid level, and now, the steering pump screams for a while when i first get going. it goes away after about 150 feet of driving, but it kinda makes me think the power steering pump is going bad.

i was wondering if this would also cause the brake light to come on? im kinda thinking that if the power steering pump is going bad, the line pressure may be low, and that could be setting off the sensor that triggers the light. but i wanted to get yall's input on that before i jumped to any conclusions.

 

[Russell]

In my experience the brake light is only activated by either the prop valve or the e-brake. My hydroboost unit doesn't have any kind of switches or whatever on it

 

[cegusman]

In my experience the brake light is only activated by either the prop valve or the e-brake. My hydroboost unit doesn't have any kind of switches or whatever on it

X2

Bleed your brakes and it should go away. Could also be a leak in your system, check all lines, calipers and wheel cylinders for leaks. The brake light coming on has nothing to do with the power steering pump portion of the setup. The only sensor in the whole setup is in the proportioning valve.

 

[K5dreamer]

ok, well i knew there was a mess in the rear drums, i thought it was leaking axle seals, it might well be blown brake cylinders. guess ill pull a wheel on the next pretty day and take a look.