funrunner91

Hello Yotatech. i have a 91 4runner v6 automatic with 4wd. i have a brake question if someone can help me out. i've changed everything up front, brake pads, guide pins, caliper gromits no seals, rotors, bearings and seals. CV's are great. when i brake at any speed the brake pedel kinda pops or shakes up and down, the pedel does not sink to the floor. no noise on the outside just inside the cab, not to loud but it just pops up and down a little bit. i'm thinking maybe some wd40 on the pedel where it pulls the pin to the master cylender....... i dont know guys. anyone have a good guess????

breknraj

How hard are pressing the brake pedal? It sounds like the ABS might be kicking in, if your Runner has it.

funrunner91

i press it normal, no matter how hard or soft i press the same affect (little jumps up and down) i don't thinks it ABS, i'm actually sure it's not ABS

runethechamp

My guess, if you have ABS, is that the ABS sensor got damaged, disconnected or something and the ABS system now thinks that the wheels are locked all the time, so the ABS kicks in all the time. If you don't have ABS, I have no idea what it is.

funrunner91

anyone know where this ABS sensor is located???? thanks guys

midiwall

There's a sensor on each wheel inside the hub. If you have it, you should be able to follow a wire down the A-arm in front (and along the axle in the rear) to the edge of each hub.

funrunner91

oh...ok....well i dont have ABS......so i will try wd40 inside the cab and let yall know tomarrow....thanks guys

regularguy412

His being a 91, I would almost bet money that it has rear (only rear) ABS and something has gone awry with either the controller or the sensor(s).

Mike in AR

funrunner91

i check for wiring up in the rear mike....thanks, let yall know tomarrow

ctcost

Yeah it's rear ABS only.

funrunner91

does someone have a picture of the abs sensor or a picture where it is located......i was under the truck last night, did not see any wireing going to the rear...(i have lights under there to see) so i get in the drivers seat and bang my head aginst the wheel, press the brake, (while the truck is off) and it sounds like a dungeon door opening. the sound is comeing from the rear??????

regularguy412

Check this link:

http://personal.utulsa.edu/~nathan-b...13generald.pdf

Mike in AR

Quakefire

You may also have warped rotors, even brand new ones sometimes come warped off the shelf. Without front ABS its almost definatly your rotors

Elvota

The ABS is rear only. Sensor mounted to the top of the third member. Bolts on, two wires coming out. Also, drum brakes in the rear of these vehicles, so no rotors.

I changed the third and removed mine but still left the sensor plugged in and tied the whole thing out of the way. No brake light at dash and no brake problems, just no more ABS. MAybe you could try to pull the switch from the third to troubleshoot the problem.

Perhaps jack up a rear wheel and check for drag. Maybe an assistant can try and locate the noise while you press the brake. Wouldn't think a noise like you described could be a hydraulic problem... unless the dungeon door is in a very high-tec castle.

funrunner91

hey thanks regularguy412....i forgot i had a rear ABS warning light.....yall are right there is ABS in the rear, how strange. i will have a better look tonight with a helper. hey and thanks elvota, i will do what you told me, get a helper and maybe remove the rear abs, but not the sensor right.....elvota, your rig is my twin, well you do have a solid axel so i'll bow down ....thanks guys and gals

lunatic14r

make sure nothing hitting the pedal under the dash. also check the booster where the booster mount the the firewall it might be a broken stud or worse a cracked firewall

funrunner91

???? hummmmm how does one go about inspecting the booster????