Brakes

Question: 2003 Tacoma 4 door, I have completely rebuilt all my brake system new master cylinder, front rotors, pads, everything flushed system new fluid and all. Sometimes when I brake the truck pulses or it feels like its wanting to shake especially when braking from a high speed. However sometimes it brakes smooth as can be with no issues at all. I have no check engine light or ABS light on either. Just curious on what to check next having a hard time figuring this one out.

Thanks for any info!

 

My 1999 Tacoma does the same thing. I had a dealer look at it and they couldn't find anything wrong. I replaced my fronts brakes myself and it still does it. No idea what is causing it...

 

Did you bleed the ABS unit?

 

Have you serviced the rear brakes? When you replaced the master and flushed the lines, did you introduce air into the ABS module?

 

Sounds like warped rotors to me. Can happen quickly sometimes even with new rotors. How long ago did you replace, and did you have the issue before replacing? If you did have the issue before replacing, it could be an issue with the rear drums if they weren't also serviced.

 

I did not bleed the ABS unit to my knowledge I'm not sure i would exactly know how to check this.
As far as the rear brakes go I just bleed the lines, I did not change brakes on the rear.

 

I change rotors twice thinking the same thing, still was an issue

 

i figure if it was something with the actual brakes front or rear it would do it everytime you hit the brakes?

 

Warped rotors, out of the box is very likely, but the fact that it doesn't occur every time makes me lean away from that possibility.. Get a dial indicator and measure the runout on the front discs. If you don't have one, make a gauge out of a wire coat-hanger or similar material, affixing one end to the caliper or similar, and bend the other end so that it almost (as in the thickness of a piece of writing paper) touch the disc and then rotate the disc. You will see the warp if it's present. Bleeding the ABS module requires either a bi-directional scan tool, or repeated activations of the ABS; if you don't have a scan tool, find a gravel road where you can SAFELY get up to say, 30 mph, and then lock up the brakes and kick on the ABS; do this 2-3 times. If it's air in the module, that should cure it.

Also, did you bench-bleed the new master cylinder?

 

i will try that, I did bench bleed

 

thanks for the help

 

Honestly, not feeling good about any of those solutions based on your symptoms... did you replace the calipers as well, or just pads & discs?

 

calipers also

 

Also a 2003 here, extended cab 4WD manual. I had a "shudder" in hard braking and the front rotors looked worn but not toast, put new pads and rotors on anyway. Still had the shudder.

Lived with it for a while, a few weeks ago I replaced the rear drums and shoes, it's now smooth as silk. My guess is that the parking brake was too tight at some point and the drums were warped. They didn't look in too bad of shape but it fixed the problem.

 

Thanks for that info i will look into that.

 

>>Sometimes when I brake the truck pulses or it feels like its wanting to shake especially when braking from a high speed.<<

When you write "wanting to shake" I assume you mean that it does shake or shudder.

If you had this problem before you worked on the brakes (and I assume you did because you didn't mention replacing anything in the rear brakes), there's a chance that the rear shoes are causing the problem. To test this, drive 4 or 5 miles and brake hard enough to get the truck to shudder. Do this 2 or 3 times, then get out of the truck and touch each rear rim. If the rim is too hot to touch, back the adjustment off a few clicks and repeat.

I learned my lesson after installing non-Toyota shoes.

 

Okay i will try that out, thanks for the tip

 

Confirm you have them on the correct sides?