No brake fluid at rear brakes when bleeding.

[Far8210]

Hi, I just replaced the master cylinder and both brake cylinders after a catastrophic failure. But when I attempted to bleed the system, no fluid would come out of the rear bleeder screw. Could anyone help point me in the right direction as to how to get this system properly taken care of?

 

[rfl]

Attach a manual vacuum bleeder to the lines (take them off the wheel cylinders) and see if you can suck anything through. The metal lines get rust in them over time and block off fluid - they may need to be replaced.

Bleed in this order: RR, LR, RF, LF

 

[kimcrwbr1]

have someone pumping the pedal and loosen the fitting at the master cylinder first. Pump the pedal and hold then loosen the fitting to let the air out then. Keep pressure on the pedal until you tighten the fitting then do it again until you only get fluid out the fitting. Drape some rags under the master as it is hard to put a dish under to catch the fluid. It can be a pain getting the air out of the master sometimes. Allways tighten the fitting before you let off the brake pedal. Do you have the hydraulic fitting wrenches make sure the fittings are good and tight.

 

[black_demon69]

Hi, I just replaced the master cylinder and both brake cylinders after a catastrophic failure. But when I attempted to bleed the system, no fluid would come out of the rear bleeder screw. Could anyone help point me in the right direction as to how to get this system properly taken care of?

did you bench bleed master? new masters usually come with 2 lengths of hose and 2 plastic fittings and the way it works is to install fittings into line connections on master attach hose to each one and other end of hoses into reservoir and submerged into fluid pump master until air is gone. then attach lines to master and open bleeder screws 1 at a time to gravity bleed then bleed as kimcrwbr1 stated....

 

[Andy D]

Don't need any special tools. Park the truck with nose higher than the back, Take the cap off the MC and open the bleeder. Gravity is your friend. If the brakes don't bleed, then there is air in the system. Check couplings for drips. tighten as needed.

 

[Tractor Dan]

Something else to check is the rubber hose that comes off the rear line and goes to the junction block at the center of the rear axle. I had that hose go bad on me. Well actually i believe it was rust and crud clogging the junction block. Easy way to tell is if you can have someone watch the brakes and see if when they are pushed that rubber hose swells up. If so that could be your issue. Once we found that and knew we had fluid up to the end of the steel line it was a simple fix and once that hose and block were replaced the brakes bled for us.

 

[bf750]

does it have abs

 

[green_duck42]

Are you located in the northeast? I had two bleeder screws that were corroded so they wouldn't let any fluid through them. I would try taking them out and see if you get any fluid. The other thing is bleeding the master cylinder. There should be a 10mm bleeder screw on the side of the master cylinder.

 

[feellnfroggy]

the rear abs sensor is on the driver framerail right ar the bend under the driver seat. it usually fails to cause this, when mine failed the guy that had it before me blocked off the entire rear brakeline. But air at that point or complete failure is entirely possible. let us know if you get it fixd