Need help from the experts. 93 f250 7.3l 4wd. on the way home hit the brakes and virtually nothing, lucky a autozone was right there and had to use the emergency brake to stop. Fluid coming out between the master cylinder and the vacuum boost. Replaced the master and bench bled it right there. Got a guy from autozone to help me bleed the brakes, but nothing is coming out of either rear brake. can't tell if any air is coming out from the engine running. seems like a line might be clogged. tried each one 3 times and nothing. does it just take a bunch of times. after replacing had enough to get home, but not safely. can you bleed the brakes without the engine running. any ideas. don't want to replace the brake line. also which one is the rear one on the master cylinder.
Thanks guys
Greg

 

Huh, I've never bled the brakes WITH the engine running...

You likely have so much air in the lines that you just have to be patient.

Standard procedure is, with engine OFF:
1. Start at the farthest brake line from the master. So passenger-rear wheel in most cases.
2. Have a helper pump the brakes 3 times or whatever it takes for them to get hard.
Make sure you have a clear hose attached to the bleeder nipple that goes into a catch-can. This stuff eats paint and who know what else.
3. Crack bleeder valve, just for a split-second. This is to keep fluid coming out, but not air getting in. The foot of your helper should not hit the floor(or just barely making contact is ok), if it does, you kept the bleeder open too long.
4. Now that the bleeder is closed, have them pump again until a hard pedal, repeat steps 3 and 4 until you see no air coming out.
If you don't see air right away, don't assume its good. May as well wait until you get clean brake fluid out, as the fluid in there is probably dirty and nasty anyway.

Repeat for the drivers-rear wheel, then passenger-front, and drivers-front, in that order.

Make SURE the reservoir doesn't run dry, or you'll have to do it all over again.
It's a real pain doing it just once...

-Joshua

 

After you bench bleed it you need to bleed the mc on the vehicle where the front and rear lines connect. Crack a line and have a helper push the pedal down one time and hold it. Close line. Do this on each line until you get no air. Then bleed wheels normally. If your not getting fluid on the wheel your bleeding, open bleeder, have helper push down pedal one time and hold it, close bleeder. Do this until you get fluid coming out the bleeder. Then bleed normal (pump 3 times and hold on the 3rd, open bleeder, close.) If both rears aren't getting fluid, try doing the 1 pump method on both sides until you get fluid flowing from both sides. Also once you get fluid flowing try letting them gravity bleed (open bleeders and let fluid drip-no pressure on the system) some before going to the 3 pump method.

 

Thanks Josh. I thought you had to have the truck running to bleed the brakes. Have not had to do it in years. Josh, what about what I have been reading about the abs bleeder. My abs light is on after changing the master cylinder. Keep in mind, I just got home a few hours ago and just am happy to get home. when I bled them at autozone, nothing was coming out of the rears.
I will do it without the engine running so I can see if I hear air coming out of the rears. I was wondering about the abs also. Hey thanks for replying Josh.
Do you think I could have a clogged line.
Greg

 

I've never seen a clogged brake line, but that doesn't mean they don't exist. There's lots of guys on here that have done 1000 times more vehicle work than me, so maybe someone else has run into it.

As for the RABS valve, that needs bleeding too. I'm not sure on the order of it, probably bleed it after the two rear tires?? I personally took the spring out of mine, as the RABS wasn't working anyway, it really tightens up the pedal. It's a good mod for guys that know how to drive in the rain and don't have working RABS anyway. Just gotta watch out for the rears locking up on you.

-Joshua

 

airdale94,
about where is that at where front and rear lines meet. I have not looked yet where you are talking about, but by cracking a line are the fittings the same as the ones that go into the master cylinder. I also wondered about how you said doing the one pump method. I think I have done that before and that sounds like what I need to do. Hey thanks man for replying. Don't have a manual and you guys are better than a manual. Almost have lifetime warranty at autozone on everything on my truck.
Thanks airdale94

 

Josh,
where is the rabs valve at.

 

Not where they meet, where they go into the mc. You bleed the mc on the vehicle (after bench bleeding) (by way as described). You shouldn't have to bleed at the RABS. I had my rears completely appart and diddn't bleed the RABS. The RABS could be your problem though. How much fluid was leaking between the mc/booster? The RABS is on the frame rail right below drivers door.

 

easiest way to see if you have a problem with hte rear system is to open hte passenger side bleeder and see if it will gravity bleed. it may take a minute to get fluid out, it may take 10 minutes.
once i get clean fluid out of the passenger side, i open the driver side and let that one bleed out.
i very rarely have someone around to help bleed brakes, and not once have i ever had any problems gravity bleeding.

 

airdale94,
ok, I got it. It wasn't pouring out between the mc and vacuum, but It was leaking. guy at autozone told me the seal probably busted in the mc. it was 21 years old.

 

tjc transport,
so just open the rear passenger bleed screw and do nothing til fluid comes out. makes sense. never done it, but i got nothing but time, because I am not driving til I get it fixed.

 

wanted to say thanks for all the help. guess I was just lucky to get home.

 

I'd bet that it's in your RABS. It's probably froze up. You can try alternating rapping on it with a hammer and then pumping the brake pedal. Or taking it apart and cleaning it. Either way the system will still probably need bled.

 

yup, that is exactly what i do.

 

tjc,
okay just tried your method. right rear passenger has fluid trickling out. did see that the bleeder screw was clogged, and cleaned it. so it trickles out, the left rear driver side has nothing coming out at all. even after 20 minutes. what should I try next. fluid coming out is pretty much black. probably never been flushed. Just want to get the fluid coming out of all of them so I can bleed in new fluid.