we have an 84 toyota 4runner 4x4 that has no brakes. This is what its been doing and what we have done. When trying to stop, we would have to pump the brakes (go to floor). At first we checked all the lines and no leaks from what we can see. Thought it may have been rear axle, but we couldn't see if it was from there with gear oil everywhere (seal was real bad). We just replaced it and no brake fluid leaking from what we can see there as well. We replaced the brake master cylinder, bled the brakes, and still none. We even checked all the lines again. Still don't see any leaks. We are getting air in the lines, but from where? We don't know what else to do or what to check. First time on brake problems. Please let us know what we can do. Thanks so much

 

Does this mean that you checked your rear wheel cylinders? take each rear brake apart and pull back the little boot on the wheel cylinders. If there is brake fluid behind the boot then you need to replace your wheel cylinders. Its common for those to go when they are that old. Id think there would have been brake fluid running down the inside of your tire however. Also when you replaced you brake master cylinder did you bench bleed it? you could have the same problem as the fualty Mc if you didnt bench bleed it. And are you bleeding them properly in the right order?

I found this for you, it might help but the above stuff i mentioned is also important

 

Did bench bleed MC till fluid coing out of both opening with no air, and also bled on truck to make sure we eliminated all air in it. We was though, bleeding in the wrong order from diagram. RR,LR, RF, LF, and at MC. Since we changed MC and axle have bled brakes 7-8 times and no brake fluid on tire rims or around area. Could it be we didn't bleed in right order? We also did not bleed LSPV at all, ever as a matter of fact.

 

Maybe you forgot to adjust the shoes.

 

A master cylinder can leak into the brake booster. The fluid will then get sucked into the engine (vacuum hose). Is the fluid level low? That's why you were looking for a leak?

 

burst a line?

 

We haven't ajusted shoes yet. Would shoes cause this problem? Brakes pump up well after bleeding but as soon as we start 4runner, it goes to floor again. Doesn't seem to be loosing fluid anywhere, checked lines best we could. We spent 2-3days bleeding and seem to be getting air every time. last time we bleed them, we did it till no air came out. Pulled front tires, original calipers on them, did notice greese on back side. Cant tell if loosing brake fluid or not. Did not see leak there out of hoses, or anywhere around calipers when bleeding and pumping brakes. Did notice pads on front were thin and seems there's not much pad left. We had to pump brakes hard (stand on them) for pistons to touch breaks, as soon as we let off, one of pistons looked like it backed off (looks like not touching brake pad at all) on drivers side. Thanks for the help, just want to drive 4runner again. I miss driving it. We're trying every suggestion we get.

 

thanks again.......

 

I also have an 84 Runner, and just had that problem, checked all hoses, no leaks, but my front pads are going out, have you checked the pads?
Another would be to check the LSPV
keep us posted on what works out for you! Good luck

 

Grovedogg, You said you had that problem. Did you fix it by replacing pads and LSPV? If not how did you fix the problem? How do we check LSPV to see if it is bad. Our pads are worn and we plan on replacing them. Was unsure if you had fixed yours or not by reply. Just trying to fix the 4runner ourselves and the right way. Thanks Don & Dawn

 

Bench bleed master then do the diagram above. If they STILL go to the floor after being PROPERLY bled, then you got equipment problems.