Im not getting any fluid to my rear disc brakes

Ive already replaced the proportioning valve and after doing that I bled them again and had some fluid coming out the rear but not much

I was bleeding them again today and I have almost 0 fluid coming out the rear. The front comes out very strong

Im guessing the next thing to repleace is the master cylinder but thought Id ask first

any ideas?

Were you getting fluid to the rear before you put in the PV?

Does the MC need to be bench bled after replacing the PV?

Do you know if the MC is pumping fluid out from it?

Do you need me to bring you a pizza?

Were you getting fluid to the rear before you put in the PV?

no

Do you know if the MC is pumping fluid out from it?

id assume that since fluid comes out very strong for the front then the master cylinder is working?


Does the MC need to be bench bled after replacing the PV?

ive looked online and cant find anyone doing that

Skatchkins wrote:

Do you know if the MC is pumping fluid out from it?

okay I pulled off the rear brake line from the proportioning valve and nothing is coming out

since its a new pv id think this makes it more likely the master cylinder is bad?

offroadaz wrote:okay I pulled off the rear brake line from the proportioning valve and nothing is coming out

since its a new pv id think this makes it more likely the master cylinder is bad?

Or you have a lot of air in the line.

so new master cylinder, new proportioning valve

2 bottles of brake fluid worth of bleeding

and







still no fluid to rear disc brakes

offroadaz wrote:

2 bottles of brake fluid worth of bleeding

How are you bleeding them?

I told him you add the break fluid with a spray bottle directly to each brake

Michael came by last night to see if we could get them working. We think it might be an electrical issue but its hard to find any relevant info online

On the proportioning valve there is an electrical plug that is suppose to regulate how much fluid goes to the front and rear

It looks like this plug isnt getting any power. We checked all the fuses but none were bad. The FSM isn't much help either, it says if there is no power it could be a fuse or bad wiring, unfortunately it doesn't say what fuse or where it might be.

found some more info

when there is a major brake failure in the front or rear the proportioning valve will automatically stop the fluid from going to those brakes

When I replaced my master cylinder we found out it was not working for the rear brakes only the front

Guessing that the proportioning valve is stuck closed for the rear since they had failed earlier. Were going to try and manually reset the valve by disconnecting the front brakes to simulate a failure and see if the valve will open back up for the rear.

tried one more thing today

took the air compressor and was able to blow air through the rear brake tube out to the bleeder valves on the rear discs. Air came out strong so no obstructions. Also checked for leaks in tube and lines and found none

cant think of anything else to try with this one, going to take it in to the shop today

fixed

I feel dumb and smart at the same time

The very original problem was the master cylinder failed. The master cylinder stopped sending fluid through the tube that goes to the proportioning valve which leads to the rear brakes

So the proportioning valve sensed that failure and closed off that internal valve to the rear

I had replaced the proportioning valve first before replacing the master cylinder. The new valve must have sensed the failure again due to the faulty master cylinder.

I then replaced the master cylinder but didnt reset the proportioning valve correctly

Evidently last night the very last thing I did was take the compressor and blow air through the tube that lead to the proportioning valve. Apparently this caused it to unstick and let fluid travel through.

In my tiredness/frustration I managed to strip one of the brake line nuts putting it back together. So when I went to bleed it again I still got no fluid

Took it to the shop today and they replaced the stripped nut, bled all 4 brakes and it works perfect

So my ideas were right then