brake light on when stopping

[95_togo]

what causes this?

 

master cylinder is relatively new (BRAND NEW not reman.)

thought it was a leak in the calipers - replaced them - luckily they were only $17 ea.

replaced leaky wheel cylinders a while ago also, along with new pads, and shoes -

 

i "thought" i bench bled the master cylinder well enough, but i could be wrong - is there anything else i should be looking for - i am also in the process of changing the brake hoses up front so pretty much everything in the system will be NEW - including the proportioning valve (replaced a while back as well)

 

so - any ideas?

 

also - i read somewhere that the consistency of the fluid can cause the light to come on????

 

would anyone recommend a FULL flush of the brake system? and if YOU recommend it, you better be able to instruct someone (namely ME) on how to do it

smoothly and easily!

[citydriver]

Sounds like you have air in the system

also - i read somewhere that the consistency of the fluid can cause the light to come on????

sometimes true,but not likely...the fluid does age and changes color as it collects moisture and dirt over time which is the best reason for a system flush.

A system flush is a whole lot easier w/a power/pressure bleeder,but most people dont have those handy...but you can do with the help of a freind...I usually start by putting the vehicle on 4 jack stands and removing the wheels,then I pump the brake pedal 4-5 times to release all vacuum assist and pressure,Then I remove as much of the old fluid as I can from the master cylinder with a turkey baster or equivelant,and clean the res...fill it w/fresh fluid..then I open all of the bleeders at the same time,(You can also gravity bleed 1 wheel at a time instead of opening all of them at once,but it takes longer)starting w/the right rear,and let it gravity bleed for about 1/2 hr while re-filling the res as needed w/fresh fluid....then CLOSE all of the bleeders...then w/the help of a freind in the drivers seat to pump the pedal(dont use your wife/girlfreind..they get bored to easily )bleed the sytem 1 wheel at a time starting w/the rt(pass) rear ,then left rear,rt front,lft front...till the fluid runs clear at each position...this usually does the trick...

 

I use gravity bleeding because my freinds dont usually have a whole lot of time for these type of procedures...they get bored too...

[95_togo]

thanks for the tip CD, but is this the correct thing for me to do?

what could be causing this problem, i replaced the brake hoses last weekend and after a bleeding it is still feeling like there is tons of air in the lines.

any ways to test the ABS to make sure that is not the problem?

i have tried removing the fuse in the past to see if that made a difference, but it did the same thing - any other suggestions?

[citydriver]

What Year is the truck? I'm assuming its a '95 and you have drum brakes in the rear...are the rear brakes adjusted correctly? Does the pedal sink to the floor or just feel spongy? Is the brake light on or go on when you step on the brakes? Does the parking brake work and do you use it? Just a few things that I would check....Also,when you bleed the system, if you have 4wheel ABS, it is a good idea to count to 15 (sec) in between pedal strokes so that the ABS valves recover.

You can also try and re-bleed the master cyl. by cracking the lines loose at the master, you can do this w/o taking the master off of the vehicle. Then when your sure there is no air in the master, try re-bleeding the system....

[redvett]

If the truck has ABS you will have to have a Tech 2 to bleed the ABS and get the air out.

[95_togo]

thanks for the replies guys, i took the truck to my mechanic friend to have my tranny replaced and asked him to look at the brakes for me - apparently the last time i did a brake job, he claims i just threw the hardware back into the drums and put them back on - we had a good laugh and all seems to be well - even the e-brake works now - CITYDRIVER you were RIGHT ON@