Brake Help (1 Viewer)

[bruegge]

Hi all,
I been having problems with my brakes. Long story short, rears don't seem to be working at all, drivers front is taking much more abuse than passenger. I have 4 runner front calipers and a t-100 master cylinder. I have adjusted the rears and while the parking brake works ok, no luck from the brake pedal itself. Front calipers seem to be working well and the rear cylinders look like they should work as well. I'm going to flush and bleed the system, but I wanted to throw this out as well to see if anyone can think of any other items I should look at while I'm dirty. I've read about a proportioning valve, maybe up near the master? but I can't find a definite answer about where it is, how to adjust. I do have a lift - maybe a couple of inches, and 33s. Can't think of anything else that will be helpful, let me know if I'm missing something. I'll post pics of the old pads, they may make this worth the read!
Thanks! Ray

 

[bruegge]

Here's a pic of the pads. Top are drivers, bottom pass

 

[bruegge]

Just Bled the brakes, no air in the system, any ideas?

 

[Kleatus]

Pads getting worn down like that would be indicitive of at least one sticky piston on the caliper.

Follow the rear brake line off the axle to see the proportioning (load sensing) valve. It is close to center in front of the rear axle on an FJ62. When you lift the truck without making an adjustment (such as a spacer the same height of your lift from the axle bracket to the arm), the brake system "thinks" you're in a hard stop without much weight over the rear axle, and reduces rear braking pressure accordingly. It's like mechanical ABS for the rear axle. Did you also bleed the proportioning valve?

 

[bruegge]

Thanks Kleatus. sorry - this is a 60. do they have proportioning valves?

 

[klinetime574]

FJ60’s don’t have an LSPV on the rear axle. They have a proportioning valve under the brake master cylinder. It is non adjustable.

With only one pad wearing like that I’d take a good look at the caliper. Replace it if it has an issue. While you’re doing that do the other side too. Brake work goes in pairs. I’d also inspect your brake lines to make sure something is not damaged and restricting one of the front calipers. Don’t limit the possibility of a collapsed hose either. If the rubber brake lines are old, replace those too.

HTH