On the road brake advice and did I misunderstand the assignment.

[Artie]

2021 50k miles.

We’re on the road and I’ve started to experience brake fade. We just arrived to camp and it’s kinda far so I apologize for the flashlight kit pics of these rotors but this is heat glazed rotors, correct?

Before we left I rotated tires and these looked like normal rotors with about 35-40% pad left.

I’m somewhat kicking myself because I just replaced the rears before we left, it was definitely time. I’m wondering if I didn’t do those correctly? Am I wrong in assuming there’s nothing special about these, off with the old, clean and grease pins, on with the new, bleed the fluid and torque the pins and lugs and you’re done… or am I missing something? The only non Toyota item I used was the slide pin grease.

I adjusted my trailer brakes this morning but it didn’t make any improvements.

We’re camping in eastern Wyoming tonight and headed for Glacier NP tomorrow, I should pass a couple Toyota dealerships on the way to get parts to replace these fronts.

I guess I’m just looking for a second opinion and confirmation that 1. There’s not some step I missed on the rears that would lead to the fronts doing this and 2. Yeah charge those fronts.

 

[doru]

It looks like pad material deposit. You are saying nothing was done to the fronts. Fronts pic shows that pads were a long way before needing replacement.
Replacing rears w/o fronts is perfectly Ok. The rears last a LOT longer than the fronts so it is reasonable to be replaced on a different schedule. Your procedure is Ok. Not many are bleeding brakes when changing pads though.
What kind of roads did you travel to the camp; how much did you ride the brakes vs. using engine brake; what load?
Once the material is deposited you need a brake job. It will not clean just by riding the brakes. So, trailer brakes adjustment is good for safety reason, but it will not fix the cruiser brakes.
Looks like you are going to a shop. If the rotors thickness is still in specs, you need rotors resurfacing and new pads. Maybe you need more aggressive pads. Make sure you bed the new pads before hooking up the trailer and going again into the mountains.

 

[TeCKis300]

How heavy are you laden or is this the heaviest you been on a trip? Are these the steepest/longest grades you've experienced? Or a combination of both?

What's the situation you're experiencing brake fade?

I don't see how the fronts rotors are significantly affected by servicing the rears unless something is royally screwed up and the rears aren't contributing.

Do you have a contactless thermometer with you? Are the rear rotors hot too (to know they are contributing).

Be careful adjusting too much brake bias to the trailer axle in the mountains . They are going to be the largest liability as drum brakes do not shed heat well.

Are you on OEM pads? At this weight level, really needs aftermarket pads for extra heat margin. I recommend Hawk LTS.

I would highly recommend engine braking aggressively and as a primary means to manage momentum coming down grades. More revs equal more engine braking and you can and should use the whole RPM band if necessary.

I have definitely faded my stock brakes before and it's scary when you realize at high weight levels how little remaining margin it is to a runaway situation. I use engine braking like it's going out of style when in the mountains.

Rotors don't look terrible but I would get them checked just to be sure. Maybe reblead all around.

 

[Artie]

It looks like pad material deposit. You are saying nothing was done to the fronts. Fronts pic shows that pads were a long way before needing replacement.
Replacing rears w/o fronts is perfectly Ok. The rears last a LOT longer than the fronts so it is reasonable to be replaced on a different schedule. Your procedure is Ok. Not many are bleeding brakes when changing pads though.
What kind of roads did you travel to the camp; how much did you ride the brakes vs. using engine brake; what load?
Once the material is deposited you need a brake job. It will not clean just by riding the brakes. So, trailer brakes adjustment is good for safety reason, but it will not fix the cruiser brakes.
Looks like you are going to a shop. If the rotors thickness is still in specs, you need rotors resurfacing and new pads. Maybe you need more aggressive pads. Make sure you bed the new pads before hooking up the trailer and going again into the mountains.

Correct, I did not change the fronts as they looked like they had plenty of pad left.

We had been on interstate for the entire time when I initially had the issue Saturday. No issues for 3-400 miles, I noticed extra effort to stop on exit ramp for gas. It’s been getting worse since then. I adjusted trailer brakes just in an effort to make sure they were working as they should.

I’ll replace the rotors instead of having them turned, this will be the easiest way for me in this situation.

Ok, I’m not sleep deprived and road crazy, you’re confirming what I see.

 

[Artie]

How heavy are you laden or is this the heaviest you been on a trip? Are these the steepest/longest grades you've experienced? Or a combination of both?

What's the situation you're experiencing brake fade?

I don't see how the fronts rotors are significantly affected by servicing the rears unless something is royally screwed up and the rears aren't contributing.

Do you have a contactless thermometer with you? Are the rear rotors hot too (to know they are contributing).

Be careful adjusting too much brake bias to the trailer axle in the mountains . They are going to be the largest liability as drum brakes do not shed heat well.

Are you on OEM pads? At this weight level, really needs aftermarket pads for extra heat margin. I recommend Hawk LTS.

I would highly recommend engine braking aggressively and as a primary means to manage momentum coming down grades.

Weight wise we’re at our typical camping weight, 14k gross, and so far it’s been interstate. Issues are exit ramps or slowing from speed to turns. Puling into this camping area its definitely acting up, extra effort to stop, trailer brakes locked up in the gravel. It’s just not right and we’re not even to the mountainous part of the trip.

These are still the factory OEM equipment and I don’t think I can acquire something other than OEM at the moment and that’s assuming the dealership in Billings has what I need in stock. It appears like they do based on the website so I’m about order parts now and I’ll call them once they open.

I do have a laser temp gun I can use on the rears, they do feel hot and appear to be braking as the machining lines are slowly going away, see pictures. What could cause the rears to not contribute? This was my first thought as this was my first brake job on this particular vehicle, I’ve done many on others before so I’m not a complete amateur. I was looking at the fronts and thinking, “crap, was there some weird Toyota specific process I’m supposed to perform” because I’ve never had issues with braking before. I probably put about 100 normal driving miles on the rears before leaving for this trip. Also, I replaced my trailer brakes over the winter and have towed with it a couple hundred miles before we left for this trip. I adjusted them yesterday morning and there is enough drag so they should be doing what they are supposed to do. It is possible I didn’t have enough trailer braking early on this trip and the fronts overheated compensating. Idk, I’ve touched 2 of the 3 axles brake wise so it’s entirely possibly this situation stems from something I did or neglected to do.

I doubt I can get the shop to do the repair for me with my timeframe so I’ll do it in a campsite or parking lot. Again, there’s nothing special about these versus another brake job, correct?

As for bleeding… I’ve always done this for brake work, that’s how I was shown how to do it back when was in high school but that was last century and older vehicles.

Regardless, you’re also confirming my suspicions so this is my current priority. I’m still 5 hours from Billings but it should be interstate the entire way.

Pics of rears after 2k miles, weights from a previous trip but probably close.

 

[TeCKis300]

The added context helps. That this is happening on regular interstates and exits is concerning.

Very well could be that the rears are breaking in before they do their fare share. Nothing to do other than use them a bit more. Sounds most likely to me.

Rear calipers are as simple as they come, nothing special with servicing.

On the other end of the spectrum, are any brakes dragging and building heat ahead of use? Same with the trailer axle? Looks like some corrosion, what's the possibility of a seized caliper?

 

[Artie]

Corrosion where? Is this from the picture of the fronts and rotor showing pad material thickness? Nothing jumped out to me when rotating tires. This is still low mileage at 50k. I had assumed the rust on the rotor to be normal. I do not feel any dragging on any corners, vehicle drives normally until braking, I would be surprised to find a seized caliper, when braking vehicle tracks perfectly straight.

Rears not broke in enough does make sense, I replaced them the week before we left. For future reference, what’s considered enough break on time after bedding in pads before towing? Just to establish we’re speaking the same language here, when I bed in these pads I had done several stops from 30-35 MPH to almost stopped then repeat this several times. After this I drove around my area in the country for about 20 miles normally. I could smell brake pads when I parked in my garage so I knew heat cycles had been occurring but it wasn’t anything unusual. After that I could tell increased brake performance and called it a successful job. When I bled the rears I had car on without engine running, brake pedal depressed with a rod against the seat. I cracked the bleeder and let the brake fluid out until it was clean.

 

[ceylonfj40nut]

Are the calipers/hubs super hot when you get fade?

 

[Artie]

Are the calipers/hubs super hot when you get fade?

I don’t know. We’re braking camp now and I will get my laser temp thing out and get some data on this. I’ve held my hand over them at the gas station and they don’t seem excessively hot but that’s not very scientific.

 

[Artie]

These are all the parts and correct part numbers I need, correct? Just making sure, coffee is just now kicking in.

Pads: 04465-60281
Rotors: 43512-60210
Shims: 04945-60080

 

[Artie]

I’m bummed I don’t have what I need to fix this now, not a bad location for a quick repair.

 

[roadstr6]

The pic you posted of your caliper and pad wear before the trip shows that the outer pad is wearing a little more than the inner. That can be an indication that one or more of the pistons in the outer portion of your caliper are seized. Use a screwdriver or a pair of pliers and see if you can leverage the outer pad away from the rotor. If it is stuck, you may need a new caliper.

 

[Artie]

The pic you posted of your caliper and pad wear before the trip shows that the outer pad is wearing a little more than the inner. That can be an indication that one or more of the pistons in the outer portion of your caliper are seized. Use a screwdriver or a pair of pliers and see if you can leverage the outer pad away from the rotor. If it is stuck, you may need a new caliper

That is going to be hard to test in the field. I wonder if a difference in temperature between sides with a laser thermometer would indicate a stuck caliper? Should I buy the calipers just in case, worse case I don’t replace them this trip and they sit on my work bench for a rainy day, the parts won’t go bad.

 

[roadstr6]

Checking as I suggested will require removing the wheel. If that's not an option, laser thermo should indicate higher temp on a seized caliper as compared with the other side. Go for a drive and shoot the thermo and see what it tells you.

 

[Artie]

Checking as I suggested will require removing the wheel. If that's not an option, laser thermo should indicate higher temp on a seized caliper as compared with the other side. Go for a drive and shoot the thermo and see what it tells you.

We just came to a pull off on the interstate. The temperature on the front was 200F on both sides, 180F in the back on both sides.

 

[Artie]

Ok. Current situation is I’m in Sheridan, WY and have pads and shims in hand. Rotors will arrive to Billings Toyota tomorrow around noon. The parts lady suggested Napa rotors if I didn’t want to wait… I’m waiting on OEM unless there’s consensus ln Napa quality here. I’ve always been a OEM guy so this feels dirty even considering it.

 

[Sajan]

Ok. Current situation is I’m in Sheridan, WY and have pads and shims in hand. Rotors will arrive to Billings Toyota tomorrow around noon. The parts lady suggested Napa rotors if I didn’t want to wait… I’m waiting on OEM unless there’s consensus ln Napa quality here. I’ve always been a OEM guy so this feels dirty even considering it.

I would wait...

 

[TeCKis300]

We just came to a pull off on the interstate. The temperature on the front was 200F on both sides, 180F in the back on both sides.

This is useful. Nothing looks out of character, both axles are contributing, and no single wheel stands out which is a good sign.

It takes more than a few hundred miles in my mind (especially highway driving) for pads and rotors to marry at the microscopic level for full friction.

Is the situation changing as the trip progresses or still not good?

Just a note that bleeding the rear brakes is different as the electronic brake booster is active and will pump pressure when opening the bleeder. I presume you bled with the ignition on?

Yes, corrosion looking at the circumference of the rotor but I don't think you have a stuck piston based on the temp readings.

How's the temp in the trailer axle hubs?

When starting a trip, I'll usually manually actuate the trailer axles to full braking to confirm connection and max braking . I once found one wheel out of 4 in my trailer to have a broken brake wire at the hub (bad crimp from the factory). The trailer pulled a little to one side which got me checking. It was subtle enough that I wouldn't have caught it otherwise as it's only 1/8 lost braking capacity.

Your situations sounds significant enough that it wouldn't just be 1 wheel out of 6, or 1/6 lost braking capacity. More like 1/3 as the rear axle isn't at full friction capacity. And at over 14k gross weight, need all brakes on deck.

I highly encourage you to upgrade those pads after this trip. It's a different level of confidence when heat increases friction versus stock pads that will give up pretty early with any heat.

 

[CJF]

Tell us more about exactly what happens: Pedal goes to the floor? Pedal is harder than normal to push? Pedal feels normal but pushing hard on it doesn't have much effect? Etc.

Also, might be useful to go for a test drive without the trailer and see whether or not things feel normal.

 

[Artie]

Tell us more about exactly what happens: Pedal goes to the floor? Pedal is harder than normal to push? Pedal feels normal but pushing hard on it doesn't have much effect? Etc.

Also, might be useful to go for a test drive without the trailer and see whether or not things feel normal.

With the trailer hitched up, petal feels normal but it requires more effort to stop.