So I have a brake concern, much like alot of people it seems. I did do some searching but nothing seemed specific to my case..so here goes.

Let me just start off in saying that I have a1989 4runner with the v6. I don't believe the brake fluid has ever been changed. During my escapades (in which youll read about shortly) I have attempted to flush it out, but its not easy getting it all the way back to yellow again.

So, I have a soft brake pedal, like really soft. I thought this was mos likely due to a bad booster, so I went ahead and replaced the booster. Nothing changed. However, when I did it, I found that the master cylinder was leaking between the booster and the master (that little cave area between the two was damp with fluid) I have since learned that that means the master is bad.

After replacing the booster, I decided I would try bleeding them and go from there. Started out RR tire...no fluid is coming out. LR wheel cylinder...no fluid coming out. However, I do get fluid from the LSPV.

Anybody have any ideas why there is no fluid coming out of the rear cylinders? On Thursday, Im going to use a mightyvac and see if I can't suck some fluid down and im going to replace the bleeder screws and hope for the best.

I know most of you are going to want to jump on the master cylinder, but I want to start at the cheapest first. I know its bad, and I know its going to take the booster out, but If i can fix my soft brake pedal, then bark down that road, that would be my goal.

 

Could be your rear wheel cylinder bleeders are just full of dirt. try getting new bleeder screws .

Unless you have removed them completely and still no fluid.

The line coming to the rear brakes has been crushed or kinked so hard no fluid will flow.

Does your emergency brake work?? If so do you always use it??

As the E- Brake keeps the rear brakes adjusted if there is to much clearance it will give you a soft pedal.

A bad booster will give you a hard pedal not soft.

Last I checked Master Cylinders were pretty cheap!!

 

Your LSPV could also be blocked up not allowing fluid to get to the rear wheel cylinders. I've had that situation on my '83, and it was a SoCal truck it's whole life. Check out the bleeder situation back there, if that doesn't do it, check out bypassing the LSPV with a manual proportioning valve. Any way you look at it, get the dang master replaced if you know it's bad! It's called the "master" cylinder for a reason.

 

Wonder if this is why I have a soft pedal as I have a t-case mounted e-brake. I get fluid from both rear bleeders and all new fluid and full. I think the axle seal might be bad and leaking into the drums and made them junk and maybe that's why my brakes are not that good?

 

Thanks for your feedback. Tomorrow I'll see if I can't suck fluid through the rear drums and ill follow up this post. Thanks

 

I may be confused, but did you replace the Master Cylinder also with the booster?