Front brakes seized!

Front brakes started sticking then got worse over time and pretty much seized up( over 3-4 days) I had to get to work so I just bled the lines which allowed the piston to retract enough to drive it. These are the front brakes I’m talking about, I figured they were corroded from salt bc I’m in Maine so I bought all 2 front calipers and replaced. I can not get them to bleed! Pedal still goes to the floor. Yes I started back right, back left, front right, front left And worked my way farthest to closest to MC. Got fluid from the tears as expected, but none from the front. I even loosened the banjo bolt where fluid comes in and pumped it until I got some fluid. Fluid level on MC reservoir isn’t dropping (filling the lines) and I’m getting no fluid from bleed valves on the new front calipers. I just bought a vacuum bleeder home from work that I’m going to try but if both brakes seized up at the same time and I can’t get them to bleed I’m beginning to think it may be something with the master cylinder? I’m hoping it’s just air bound, what are your thoughts and what should I do/check. Thanks

 

This happened to me in my 2nd Gen last winter, thought it was only the left front caliper and I didn't notice a difference in braking performance. My truck just creaked and squeaked a lot until I couldn't take it anymore. I finally brought it to the dealer (NEVER AGAIN!) expecting that something would need to be tightened, and it ended up that my front brakes were pretty much shot. My truck passed PA state inspection with the front brakes at about 50% in October 2017. In March 2018, the noises were really bad and I found out my brakes were shot when I brought it to the dealer.

They then attempted to charge almost $1,700 for calipers, pads, and rotors until my neighbor of all people gave the service manager a piece of his mind and they knocked it down substantially.

 

Yeah I do everything myself for that reason, pads and rotors and now calipers are good. Just brakes started seizing. I’m wondering if it’s the master cylinder...

 

Abs or non abs? If it's abs, you might have a plugged motor/pump

 

It’s ABS. How do I go about that?02hilux

 

What you can do is cover the engine bay and fender very well to prevent brake fluid from making long contact on the paint. Take off the rubber brake line to metal tubing connection by frame and use compressed air to pressurize the hard line going to abs pump back to reservoir. If there's any clogged, this should work force it out. Safety goggles is your best friend at times like this.

Do at your own risk

 

So you changed both caliper and no fluid is present now?

 

When I bled it off to get to work after they seized I tried to bleed them when I left work with the same results I’m getting now. No fluid, no drop in reservoir level, and pedal goes to the floor. I figured the pistons were seized so I replaced them.

 

Seemed like a clogged line/pump or a defective MC. If you have a leaking seal in the piston of your MC, under pressure, fluid will leak pass the piston instead of traveling to brake line.

With engine off, try pumping the brake pedal 2-3 times and hold it. See if the pedal will travel slowly down, past the initial stopping point. If the pedal slowly travel down, you might have a leak in the MC.

If there's no pressure at the pedal at all regardless of engine is on or off, you might have a defective brake booster. You can test the booster with a handheld vacuum pump and see if it's holding vacuum. Also check vacuum hose connection from booster to intake manifold, make sure it's not leaking.

 

With truck off and pumping it 2-3 times and holding. It catches a little “squish” at the very bottom then continues to compress. But there is no fluid in these new calipers. I do have a vacuum bleeder.. if I try to purge the line with air I should probably leave the cap on the reservoir huh? Haha.

 

Sound like a leaking booster. But try to purge the line first and see if it'll help before you start buying parts.

Yea, leave reservoir cap on to prevent fluid from going everywhere. Cover under and around the booster area as well incase fluid is forced out.

Wear face mask / goggle to prevent injury to yourself. I'd seen some clogged line not willing to budge for the first few minute and compressed air is force out of blow gun/ hard line and into the operator's face.

 

That’s not a good time. I don’t see how to undo the rubber line from brake line. It seems to be crimped. I’m going to purge it in through the bleed fitting. Better than nothing

 

When you were bleeding and started at the rear did fluid come out there? If so your mc should be fine.

 

Or that, but pressure can leak from threaded bleeder end and the hole from bleeder screw is very small.

The rubber to hard line should be cramped. The connection is by the frame.

 

Ok, I see it now. I took the bleeder valve out and purged with air (rubber tip on air nozzle for snug fit) it made it into the reservoir (bubbles like a bong hit) and now my pistons have extended onto my pads where they aren’t loose anymore like they were. Which I’m sure is just air but still

 

Pedal still goes to the floor, Hooked the vacuum bleeder back up and no fluid coming out still.

 

Next, undo the 10mm hardline going into the farthest fitting on your MC/firewall. That should be the line feeding your front caliper. Use a towel to absorb any leak. Have someone slightly depress the pedal while another person is watching for fluid to squirt out.

 

It’s just me here solo dolo man ‍♂️.

 

Then test your booster with a handheld vacuum pump? Should be able to hold vacuum without leaking if its a good booster.