HELP!! Smoking front brakes!

Just use the Motive as a pressure pump. Don't put fluid in the container, that is what makes a mess. You have to watch the resevoir to not pump it dry.

 

So the issue is still rearing its ugly head. Drove to work this morning and the same thing happened, brakes wouldn’t release pressure. I brought a wrench with me and I cracked the bleed valves, released pressure, closed them and drove to work fine. As I pulled into the parking lot, they started to not release pressure again.

I ended up pulling off the vacuum hose to the brake booster and plugging the outlet from the engine, leaving the brake booster to vent to atmosphere. While the brake pedal was incredibly stiff and the brakes didn’t work that well… The truck drove perfectly fine back to my house without issue and the ride was actually remarkably smooth.

Any input on that?

 

https://www.tacomaworld.com/threads/brakes-locking-while-driving.799314/

Look at post 18. In his case, sounds like it was what he called a loose pedal rod. A little bit of searching, I can’t tell if there’s anything between the pedal and booster/master cylinder area that can come loose. If there is, I’ve seen them found loose and spinning causing low pedal, no brakes and high pedal, locked brakes.

 

Looked at that post and some other articles etc. Right now I have a high and extremely hard to push brake pedal. Something else I read says that there’s a change I either damaged something internally to the master cylinder or messed up that brake booster pushrod when I *accidentally* bled the brakes wrong.

I also read a couple articles that said some valves could be gummed up. I’m at the point now where I believe it has to be something within the master cylinder and brake booster.

 

How long did it take for this to happen today?

 

The brakes were locking in about 2.5 miles. I released the pressure and they were locking back up by the time I rolled into work about a half mile later. After venting the brake booster, I had zero issues on the way back home.

I currently have taken the master cylinder off and am researching how to measure the brake push rod depth.

 

Somewhere you might see something like this. I don’t know what vehicle the picture showing the part is for.

The goal would be to shorten the rod which will increase pedal travel. It’s a little tricky. Grab the rod, with the pedal up, it probably feels tight. Shorten slightly, grab the rod again, keep shortening until when you grab it it’ll rattle a little. You want it so it’s just barely short enough to rattle. Tighten the lock nut. Get in the seat and use your foot to see how it feels. You should have some travel but nowhere close to hitting the floor. You might need to start it to get the booster going for this.

Keep in mind this is a generic instruction. Someone will hopefully chime in with access to the manuals.

 

Hmm, might the Haynes or Chilton manual have this? If so I'll see if I still have mine

 

I mean, they were advertised appropriately

 

I would recommend NOT adjusting anything right now....the adjustment as it sits worked fine for however many miles...and it didn't just change, so before you go down that road...

Hook the booster back up.

Get some tools ready to work sorta quick so you get this done before things cool off and they release on their own...Go get them to start dragging again then get a jack under one of the fronts (so you can spin the wheel to gauge progress)... Perform the following steps until the brakes release.

1: Remove vacuum source from booster
2: Unbolt master cylinder from booster and pull it away about 1/4" or so
3: Loosen brake lines at master cylinder
4: Loosen brake line at frame/hose connection
5: Loosen bleeder (which we know will release them)

This is how we pinpoint where the problem exists, after which we can then determine how to fix it.

 

If you read through this posting, he had similar symptoms.

You’ll need to dig in and try to locate what he’s calling a pedal rod. I’m guessing the lock nut is loose. This is something I’ve found at least a couple dozen times chasing a symptom of high stiff brake pedal and brakes dragging OR low brake pedal and weak brakes.

If there is an adjustable push rod, which it sounds like there is, then there’s probably an adjustment procedure in a Toyota service manual.

 

Follow up?

 

I had something like this happen when I replaced the rear pads on a vehicle. I replaced the caliper and still, the brake would lock up. I ended up replacing the master cylinder and power booster at the same time. Problem solved.
My theory was when we bled the brakes, I let the pedal go to the floor. The pedal had roughly 6 inches of travel and the booster was only about 3 to 4 inches wide. So I figured I damaged the diaphragm. Now I lay the wide end of a 2x4 between the firewall and brake pedal and use a check valve at the bleeder going into a container. I don't have a power bleeder.

 

Sorry! I was gonna wait till it’s resolved fully.

Currently my trucks in the shop. I started getting frustrated with it and broke a plastic clip or two and decided to throw the towel in. I’ll follow up once I get the truck back

 

I see you’re in Anoka county! I’m in Hennepin. Small world!

I’m fairly certain I’ve done the same thing with my truck however I wasn’t wanting to jump straight to replacing parts with out diagnosing first and I was having a hard time even doing that. Plus I was worried I would buy the new parts and then damage them as well because I didn’t know what was going wrong. So I relented and my trucks now in the shop.

 

There is your answer there should be no reason for it to be tight. You should able to force the piston all the way in enough to have a gap between the pad and the rotor.

 

Haha we’re past that, it wasn’t the issue.

 

Update: Ended up getting my truck back from the shop on Wednesday. $1,735.40 later, it’s running good and brakes how it should. I got a new master cylinder and a new ABS module out of it. They also ended up giving me back the front driver reman caliper to warranty it and get a second new one as it was frozen already. So I went through 1 new set of calipers and am now on the second new set. I was definitely concerned with them saying it was the abs module after reading some other threads, but everything seems to be working so fingers crossed. I have a 30 day warranty on the abs module since it’s reman so I’m driving the heck out of the truck. Apparently Toyota no longer makes the Abs Modules so the only thing available is reman modules.