Hey guys - I've searched and searched but nothing in the archives about this:

If I want to completely purge the brake system of all air, should i first bleed the master cylinder (at the two lines going into it) before bleeding each wheel? The Chilton's does not address this...no big surprise there. I just want to make sure it's done in the correct order. Appreciate any input...thanks in advance.

JSCB
'92 F150 XLT 4x4 155k

 

I usually start at the right rear then go to the left rear then right front and left front ... but with ABS you have to bleed the ABS valve also ... it is on the frame about under the area of the pedals .... after all that if you still have air then the master cylinder would be the next place to go.

 

This is probably one of those things that everyone has a opinion on but my old school shop teacher always told us to start with the wheel closest to the master cylender and work your way to the furthest.
LF Rf Lr Rr as you are sitting in the vehicle.
It can probably be done effectivly other ways but it has always worked great for me.
Pick up one of those vacume bleaders if you don't have help, they do work really well. Kind of suprised me when I first used one.

 

Thanks for the advice Silverdude. For the benefit of those that would like to learn from my venture, here's how it all unfolded:

1. Replaced the front pads; down to minimal lining but not completely done. The rotors were still good, just brushed 'em with 150 grit sand paper.
2. Bled all four wheels and the RABS valve. During the bleed process, I noticed the LF bleed screw was clogged with junk as the fluid dribbled from the caliper hole several times instead of out the screw. Oh well...bled it anyway.
3. Test drove. Everything initially seemed okay but lost some brake pressure after about 10-15 brake applications. Drove it back into the garage.
4. Checked all four wheels and noticed an ever-so-slight dribble from LF screw at the caliper hole. Hhmmm, could there be a leak? Took off the wheel and had a closer look.
5. Took the bleed screw out and all kinds of rust and crap floweth from caliper hole. Went to part store to get a new self-bleeding screw. I returned from the store to find ALL fluid from M/C had drained out of LF caliper hole into bucket placed under the wheel...all kinds of rust 'n gunk in the fluid.
6. Hhmmm, I must have intoduced air into the system again, including the M/C. Checked the Chilton's (not much help) and posted on this board for advice.
7. Took Silverdude's word and bled all four wheels and the RABS again with thanks to the wifey for the pedal-pushin' help.
8. All done but still a super spongy pedal...s-h=u=u=t!
9. Then bled the M/C at both line connections, again per Silverdudes advice. Some air bubbles did flow out...guess there was some air in there!
10. Test drove....SUCCESS!!!!!! . Good 'n hard pedal all the way.
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Just thought Y'all would like to know. This board rocks!!

JSCB

 

I've always been told start at the wheel farthest from the master cylinder, and work your way to the closest. Oh well though, to each their own!

 

Yeah, that's what i've always done and did it this time too. In fact, that's the ONLY thing that Chilton's got right with the brake bleeding procedure.

 

Glad to help ... I didn't bleed my MC ... guess I should, my pedal is hard, but sinks if I get stopped on an incline.

There was a lot of crap in my lines when I did them .... I don't think they were done for at least 10 years before I did them.

What you did when you went to the parts store is called gravity bleeding the brakes, the guys at the hobby shop always told me to do that on my DUB .... doesn't work as well there.