Q: No brake fluid is getting to the rear brakes

asked by on September 27, 2016

I have been trying to figure out why my rear brakes are not getting any brake fluid. This problem just occurred this week. I had to replace the master cylinder and also the front right caliper because someone put power steering fluid instead of brake fluid in the master cylinder. My van has an ABS system. Before mounting the master cylinder, I pressurized it. To try to gravity bleed the brakes, my friend and I put the van on level ground and all four bleeder valves opened at each wheel. However, we could not get any fluid to come out at the rear brakes. So we closed the rear bleeders and worked on the front brakes, bleeding them individually and the process went well. Then, underneath the van, we disconnected the brake line that was going to the rear brakes. No brake fluid! I am wondering if the problem is the proportioner valve and if it has rubber seals that might be swollen up from the power steering fluid. Or, I am wondering if I should bleed anything on the proportioner valve. I am an amateur mechanic and have a little knowledge about car maintenance and repairs; however, I am not educated regarding the ABS system. I can change the brakes and lines and things like that. My van has front brakes and since I put on the master cylinder, the brake system light and the ABS light are no longer illuminating. But it seems illogical that those warning lights would go out when I do not have rear brakes. My van has disc brakes on the front and on the rear there are drum brakes. I would very much like to perform the repairs myself, if possible. I have to travel 2 hours a day to/from work and I really need to get this figured out. One more thing: we did not replace the front brakes because we assumed that the lines are not swollen since we were getting fluid from the bleeders. In your professional experience, what can my friend and I do to get my van in good running condition?

Brake System Inspection $94.99 - $114.99 Get a Quote

As far as the brake issue, yes, there needs to be a check to see if there is brake fluid entering into the proportional valve. If there is fluid supply to the valve but not out then the valve will need to be replaced. Any electrical faults in the rear ABS system are generally indicated with a light illuminated and if so, then the flash codes can be read out. But with no light illuminated then there most likely no electrical failures in the system. If the source from where the brake fluid supply cannot be located, then you may want to enlist the help of a mechanic, such as one from YourMechanic, to help with the diagnosis of your brake system.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

How do I unlock a door without a key?
There are two ways to unlock one of the car doors without a key: 1. From inside the vehicle, pull the door handle to open the door. This will automatically unlock the door, and open it. This feature only works...
When hitting a puddle, car died & had buzzing noise
Hi. Thanks for writing in about your 1996 Nissan 240SX. It is likely that you have some stationary water on top of one of the circuits or inside of one of the connectors causing the fuses to blow (https://www.yourmechanic.com/services/fuse-replacement). I wouldn't...
Power steering loss
Hi there, thanks for writing in about your 2001 Mercedes Benz ML430. This problem could be caused by a slipping belt (https://www.yourmechanic.com/services/drive-belt-tensioner-replacement) or a faulty belt tensioner (https://www.yourmechanic.com/services/drive-belt-tensioner-replacement). The power steering pulley needs to be observed while the car is...
P0755 & P0700 error codes
The problem with buying used tires and not having them balanced is the potential problems they can cause. Most transmissions - or more specifically, the Powertrain Control Module (PCM) which controls the transmission and drive line - contain incredibly tight...
Car completely died with all symptoms of bad altenator while it was raining next day starts right up what could that be?
Hello and thank you for writing in. With the multi symptoms that you are experiencing with your vehicle, there are a couple things that are wrong. The first thing is the ignition switch probably failing. All of your power devices...
While I'm driving the accelerator disengages and it won't accelerate with the gas pedal pressed all the to the floor.
This loss of accelerator control is a built in safety feature of the vehicle computer and can render the throttle inactive if it sees a problem in a major component or loses communication with the throttle sensor. I have even...
My AC compressor locked up and my steering wheel belt snapped and my car begin to overheat. What is the cause?
Either the air conditioning compressor or clutch has failed. Most of the time the clutch fails and locks to the compressor housing causing the compressor to not turn. If the air conditioning was off when the belt seized, then the...
My 2011 Ram 1500 Hemi randomly stalls while coming to a stop, and/or while in a slow turn.
Hi There, It sounds like you may have a dirty or failing idle air control valve causing your engine idle to fluctuate. The idle air control valve (https://www.yourmechanic.com/services/idle-control-valve-replacement) is a small valve on the engine's intake system that reads the...

Related articles

How to Buy a Good Quality Brake Hose
Brake Brake hoses, sometimes used interchangeably with the term “brake lines,” carry brake fluid between the master cylinder and the wheel cylinder or brake calipers - depending upon the type of brakes you have. The pressure from the brake fluid...
How Long Does an Electronic Brake Control Module (EBCM) Last?
Technology Technology has come a long way where cars are concerned, and the braking system is one area that has really benefitted from advances. There are now all kinds of safety features that are built into the braking system that...
How Long Does a Vacuum Pump Last?
Your Your car’s engine is a very complex piece of machinery. In order for it to function properly, there are a number of different components that will have to work together. Among the most important aspects of an engine is...