Brake fluid is not reaching the wheel cylinders

Sounds like you have a leak in the drum brake wheel cylinder. They happen, and more often than you would expect.

You'll see in the pictures, one is the new part and the other shows where it is on your truck.

If the cylinder went bad, you'll see brake fluid leaking, even slightly, out of the rubber boot on either side of the cylinder.

Your problem could be several things #1 Are you bleeding the brakes properly , start at passenger side rear wheel. Have someone t sit in drivers seat Have them push brake pedal down ,open bleeder.,close bleeder ,have them let brake pedal up . push pedal down again ,you open bleeder again than close bleeder,have brake pedal up continue doing this until a stream of brake fluid without air comes out.( never pump the brake pedal while bleeding) if this is not working after 30 or more cycles you may need to replace your master cylinder. if this was helpful please leave goodback

Check for restrictions in the brake line, it may allow fluid pressure to reach the wheel cylinder but not return easily enough to let the wheel cylinder retract fully. The rubber boots, no that would not cause this. Is you don't say what wheel front of rear, makes a big difference.

Hi Chris, The brake system is basically very simple. If you have duel braking on your vehicle, the usual method is having two brakes operate on the front with for example the left rear and the other system will also operate two front and the right rear. This type of system will have two calipers on each of the front wheels. The tandem system works in a slightly different way, having the forward part of the cylinder pressurizing the rear brakes and the rear part of the cylinder pressurizing the front. I think under the circumstances you are describing, I would have a friend sit inside and pump the brakes repeatedly until the system becomes pressurized (maybe twenty thirty times of pumping the brake pedal) and then ask him or her to keep it pushed firmly down until you find out where its leaking. The amount of brake fluid you report having been sed would indecate a severe leakage. Check the lower parts of the rear wheels for signs of leaking wheel cylinders and then dito for the front wheels. Any signs of wetness at these areas and along the brake system (the plumbing or pipe work) will indicate where the leakage is. If you cannot identify a wheel which is leaking, carefully inspect around and blow the master cylinder and if this no sign go along the fluid lines, taking special note of where the damaged pipe was repaired. If there is a blockage in the line, air may be trapped at that point causing difficulty in pressurizing. Once the place of leakage has been identified it must be attended to before bleeding the system. When bleeding, begin with the wheel furthest from the master cylinder, and work your way back to the master cylinder one wheel at a time, until you reach the closest.Keep in mind that you may find it required to pump the pedal many many times before opening the bleed nipple.Regards John

check right rear wheel cylinder.the wheel cylinder bleeder screw could be loose or brake line to rear brake hose or brake line broken.the rear wheel cylinder seal is leaking brake fluid.

1- New master cylinders could also fail, possibly due to bad quality replacement parts or maybe even just a factory fault on a good quality master cylinder.

2- If you had blown a rear wheel cylinder, you most deffinatly should still have had a form of front brakes. the reason for this is as follows... For this very saftey meassure manufactures design the container for the brake fluid supplying the master cylinder in two internally, so this would mean that if you where to drain all the brake fluid through the rear wheel cylinders an acceptable amount of brake fluid should still remain within the one compartment of the reservoir for the front brakes to still opperate.

3- Leaking rear wheel cylinders should have been noticed by the technician who installed the master cylinder, the reason for this is because the brake fluid would have had to be bled through the system at each wheel. even though it would have been performed from the back of the wheel one would expect the technician to notice the brake fluid dripping out behind the brake drum.

I hope the above is of assistance to you.

Regards.

If they are drum brakes then it is most likely the wheel cylinder. these are not expensive but you will need to replace the rear brake shoes and clean all the parts with brake clean. I recomend replacing the other cylinder while your at it.

Here is the procedure from the service manual. I would add just one thing. Do each wheel in this order

1. right rear wheel
2. left rear wheel
3. right front wheel
4. left front wheel

BLEEDING

HINT: If any work is done on the brake system or if air in the brake lines is suspected, bleed the air from the system.

NOTICE: Do not let brake fluid remain on a painted surface. Wash it off immediately.


a)FILL BRAKE RESERVOIR WITH BRAKE FLUID Fluid:SAE J1703 or FMVSS No. 116 DOT3

b)BLEED MASTER CYLINDER HINT: If the master cylinder has been disassembled or if the reservoir becomes empty, bleed the air from the master cylinder.

c)Disconnect the brake lines from the master cylinder. SST 09023-00100 Slowly depress the brake pedal and hold it.

Block off the outlet plug with your finger and release the brake pedal.
Repeat (b) and (c) 3 or 4 times.


BLEED BRAKE LINE

1. Connect the vinyl tube to the caliper or wheel cylinder bleeder plug.
2. Depress the brake pedal several times, then loosen the bleeder plug with the pedal held down.
3. At the point when fluid stops coming out, tighten the bleeder plug, then release the brake pedal. Torque: (Bleeder plug) Front brake caliper
: 8.3 Nm (85 kgf-cm, 74 inch lbs.) Rear wheel cylinder: 8.5 Nm (87 kgf-cm, 75 inch lbs.)
4. Repeat (b) and (c) until all the air in the fluid has been bled out.
5. Repeat the above procedure to bleed the air out of the brake line for each wheel.

CHECK FLUID LEVEL IN RESERVOIR Check the fluid level and add fluid if necessary. Fluid: SAE J1703 or FMVSS No. 116 DOT3

Replace the master cylinder the rear has failed due to lack of fluid.

I would replace the MASTER CYLINDER. BLEED AIR from master cylinder BEFORE INSTALLATION. Hope this helps