spongy mushy brakes

[Sykoslug]

Recently had spongy mushy brakes driving to my neighbor's house (thank god it was just around the block) - and got to reading all the 100 series failure issues. After checking all of the lines and the area around the MC under the hood and by the brake pedal for cracks and leaks - and not finding any, I ordered the new MC piston. THEN, I realized that I had overfilled my reservoir about 3 weeks ago, since I hadn't followed the procedure of pumping the pedal to evacuate the accumulator first. OOPS, newbie owner of a 100 series - lots of electronics to be aware of - my 60 is so much less complicated.

This morning I removed the excess brake fluid using a 300ML syringe and hose, then ran the pump motor run-time test (30-40 sec is spec). Test #1 - 40 sec, Test #2 30 sec. Good enough.

Satisfied with the results I took it for a spin and had my brakes back to normal: little bit of play but great stopping power and confirmed the ABS was working to slow me down from 40MPH hard braking runs.

At this point I'm going to leave the system alone and read the manual before changing anything else.

Thanks to all the Land Cruiser Sleuths who have helped make owning and maintaining these cool rigs possible.

PS- Also check the resistance wire leads under the ABS module - shiny and beautiful. I added a bit of dielectric grease just to be on the safe side.

 

[Skruf]

Bump

 

[take123]

So I changed both my front caliper brakes today. I rebuild the whole thing. So I took apart the caliper, both hoses were draining into gallon water jugs, and I put in cleaned up pistons and shims and pads and then remounted the brake line. By then the caliper is completely empty of fluid and the line is drained out a lot and the brake fluid container by the master cylinder drained low.

Refilled the brake fluid container, had my bleeder valve closed, and then made the mistake of pumping my brake pad while the car key was in "ON". After maybe 40 steps the car started beeping alarming with the brake warning light on, and I think something went wrong with the master. So I stopped pumping and let the car sit. Eventually the beeping alarm went off.... thank god thought I needed replace the master. I think the pump was overworking when I kept pumping it and wanted me to stop......

The brakes at this point were very mushy still. Driving the car it's hard to stop.

So then with the front tires still mounted (too lazy to take tires off, you need to crawl under the car but theres space to access the bleeder), I opened the bleeder valve on right side, put a hose on the bleeder valve, had it dangle into a gallon water jug, and then pumped the brakes 20 times, I saw the hose was clear and clean with no bubbles, so then closed the bleeder valve. I initially had this brake bleeder tool where you have a pump you can use your hand to squeeze and it pulls brake fluid, but it was garbage as it kept inserting air somehow into the line, so I just threw away the tool and went with good old fashioned using the brake pedal.

Then I did the same with the left side. The brakes got pretty firm at this point. Car is off still.

Filled the brake fluid tank back to 3/4 to max.

Started car, heard the master cylinder spinning doing its job (made sound for like 15 seconds), no alarm beeps, brakes feel tight. Good ! Waiting for the rain to stop to do a test drive.....

 

[Skruf]

Currently battling my own less than adequate brakes. To get enough braking force to get the abs to engage on a wet road I need to physically put all my weight onto the brake pedal.

When I do this the pedal goes almost to the floor and interestingly when I remove my foot it stays depressed and slowly returns to normal height.

The brakes are a bit spongey but fine for normal driving but definitely not what they should be for an emergency situation.

It has new fluid and new soft brake lines. New discs and brake pads.

Does anyone have any thoughts about what to tackle next?

Oh and when I tried to bleed the brakes via techstream, it only gave me an option for the front brakes..which seems odd.

It's a 99 lx470

Cheers