Bleeding your brake system
By Steve Leslie
***DISCLAIMER - Please note
that this writeup reflects my experiences only and anyone using it for reference
or as a guide, etc. does so at their own risk. You may link to this writeup, but
you must obtain my permission to re-post it elsewhere.***
So if you didn't replace your calipers
(or otherwise open up the system to the air), you're asking why should you bleed
your brakes? Just like any other fluid in your Jeep, brake fluid should be
changed every so often. One quality about brake fluid is that it absorbs
moisture, which not only makes the fluid less effective...it lowers the boiling
point. If the fluid boils, gas is released and suddenly there's air in the line.
Bleeding every so often (1-2 year intervals) helps prevent this.
There's tons of writeups and methods for bleeding brakes (just do a google
search). I prefer to use a vacuum pump. It allows one person to do the job, and
there is no necessity to touch the brake pedal, allowing me to watch the master
cylinder (it should NEVER be run dry) as well as what is coming out of the
system. Also, like the c-clamp it serves other purposes besides just bleeding
brakes...it works anywhere you need to create a vacuum. You can pick them up at
most autoparts stores for around $50...I think Walmart even sells them.
Some people are going to chime in about speed bleeders which are very sweet and
make quick work of bleeding brakes...but if you're like me and have 6 vehicles
to maintain, consider buying a set of speedbleeders for each one at around $50
per vehicle. Then compare that to a $50 vacuum pump that has other uses as well.
Anyway, back on point...this is the vacuum pump in the configuration used for
bleeding brakes.
A few general rules first, always start at the wheel with the longest hydraulic
line to the master cylinder and work around the vehicle to the shortest. For us
here in the States it would be right rear, left rear, right front, left front.
Never let the master cylinder run out of fluid, so make sure to have plenty on
hand. Also, don't re-use the fluid...would you drain the oil out of your engine
and then turn around and pour it back in?
The process itself is simple but time consuming, connect the end of the hose to
the bleeder screw, use the pump to create a vacuum and then slowly and slightly
open the bleeder screw:
Check the master cylinder often and add fresh fluid as necessary. When the fluid
runs clear and you see no air coming out of the line, close the bleeder screw
and move on the the next wheel in sequence.
After all four corners have been bled, start the vehicle and step on the brake
(if you have installed new pads, you might have to pump them to compress the new
pads onto the rotors and bring the pedal up), then turn off the engine and hold
the pedal down. If the pedal does not sink after 15-20 seconds, you're set. If
the pedal does sink, the system should be bled again.
***DISCLAIMER - Please note
that this writeup reflects my experiences only and anyone using it for reference
or as a guide, etc. does so at their own risk. You may link to this writeup, but
you must obtain my permission to re-post it elsewhere.***
