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

[Artie]

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.

The situation appears to be getting slowly worse as the trip progresses. Both of the trailer hubs measure 80-100F and are the same on both sides when measured.
I did bleed the rear brakes with the ignition on.

To bleed front brakes, pump brake, hold down, open bleeder while holding petal down with ignition on?

We’re going to drop off the trailer in Billings, then drive to Bozeman to pick up OEM front rotors, will test braking without the trailer at that time.

 

[Artie]

We unhitched today and I have aquired all the parts. Braking is better without the camper but that’s not a surprise. However, once any heat is built up it loses braking and requires more pedal.

Tomorrow, @WreckDiver1321 has offered me space to do the repair, saints live among us and I’ll meet one tomorrow.

 

[Sandroad]

I wonder about the brake bleeding. Is there any chance by doing that you introduced air into the rear calipers or the system in general? Bleeding the rears is different than bleeding the fronts.

Edit, I now see the other posts earlier about proper bleeding. I would still do it again just to be sure.

 

[Artie]

I wonder about the brake bleeding. Is there any chance by doing that you introduced air into the rear calipers or the system in general? Bleeding the rears is different than bleeding the fronts.

Edit, I now see the other posts earlier about proper bleeding. I would still do it again just to be sure.

Anything is possible and I find my self questioning everything at this point. I don’t see how air could had gotten in with the method I used since the booster was providing pressure the entire time the bleeder was open. I do plan on checking the rears tomorrow and I even picked up a set of pads just in case. I plan on vacation and not any more brake repairs.

I keep reminding myself that there wasn’t a problem before I touched the rears but now there is… I’ve done lots of brakes so I’m not that dumb but mistakes can happen. I’ve gone over my work a million times in my mind… is it possible I stuffed the rubber boot in with the slide pin on both rotors and caused them both to not operate, I don’t think that would all fit into that hole but at this point I’m laying my eyes on them to rule it out.

It’s becoming a theme on our big summer trip to have a repair, this is a theme I need to change.

 

[bloc]

I wonder if those stock pads just aren’t up to the task of your GVWR, and installing new rears then needing them to bed in pushed the fronts into a weird state where they are transferring too much material to the rotor and this is somehow impacting friction coefficient.

I had a pair of stock fronts basically start disintegrating because I had pushed them too hard in the mountains. When I removed the front pads the friction surfaces weren’t flat and could be broken apart further with aggressive scraping. No soft pedal as though I ever boiled fluid.

That was when I moved to TRD pads for a couple changes, and now Z36s.

I’d be really curious what the surface of your front pads looks like.

 

[vipergrhd]

Did someone ask if you could lock your trailer brakes? Are they electric or hydraulic?

 

[ppc]

None

 

[Artie]

I wonder if those stock pads just aren’t up to the task of your GVWR, and installing new rears then needing them to bed in pushed the fronts into a weird state where they are transferring too much material to the rotor and this is somehow impacting friction coefficient.

I had a pair of stock fronts basically start disintegrating because I had pushed them too hard in the mountains. When I removed the front pads the friction surfaces weren’t flat and could be broken apart further with aggressive scraping. No soft pedal as though I ever boiled fluid.

That was when I moved to TRD pads for a couple changes, and now Z36s.

I’d be really curious what the surface of your front pads looks like.

Your theory is completely plausible. The issues began after I switched the rears. Either they hadn’t finished breaking as you said or I did something to cause them to not function properly. It could also just be unfortunate timing and the fronts have been getting to this point naturally from the weight and use case. Regardless, I’m obsessing about it at this point but will have more insight on it today.

GVWR is high so switching to more heavy duty parts is a priority when we wrap this trip.

My pedal isn’t soft or spongy but it does feel like it reaches a point to where it needs more force than it used to, almost like it hits a wall and it needs slight extra force to push through. Again, I keep obsessing over my steps in doing the rears… could I have used to much grease on the pins causing a ram effect so the caliper doesn’t move as it should? As mentioned, I did not have access to the Toyota brake grease stuff but I did use brake grease…this has been an area of obsession for me. Pedal isn’t spongy so it doesn’t seem like air. I will check the rears today as well.

I’ll post pics once it’s taken apart.

 

[Artie]

Did someone ask if you could lock your trailer brakes? Are they electric or hydraulic?

Electric drums on the trailer. I had one moment the other day where I had to briefly brake hard in a merging situation and they locked for a second, then again on some hard braking in gravel. These two instances are normal for those two scenarios. Both came from a brake engagement, one where someone merged almost into me, the other on gravel where I almost missed a turn. The trailer brakes locking slightly in those situations seems normal to me. They are definitely operating as I’ve been used to in the past.

 

[Smokinjo]

Just remember if you change your front pads and rotors you will need to bed them in as well before towing that trailer. Otherwise you will not get the result you are looking for from the front replacements

 

[Artie]

Just remember if you change your front pads and rotors you will need to bed them in as well before towing that trailer. Otherwise you will not get the result you are looking for from the front replacements

I was just discussing this with my wife. My plan is to leave our camper here at this campsite while I do the repair. Then I’ll do the initial bed in process (several stopping sessions from 45mph to almost stopped several times) then stop and let it cool for 10 min or so. Then I plan on driving on the interstate and a little bit but breaking gently.

My plan is to get 200-300 miles in without the trailer. We can lose a day at glacier and stay here in Billings another night to get in more break in miles.

How many would you think I’d need to be safely broken in enough to tow?

 

[TeCKis300]

Sounds like a good plan to get back on the road.

From what's described, it maybe a confluence of factors. Between the rear pads breaking in, trailer brakes needing more gain, the fronts got overworked and glazed. Possibly to the point of compromising the whole of the pad material. 14000+ lbs gross is A LOT of rig for stock pads and any issues would not be forgiving at that weight level. With 50k adventure miles on original? rotors with less mass and thermal sink.

Regarding the rear pins, they allow the caliper to float and shouldn't prevent max braking, I think. They should be lightly lubricated rather than packed?

What's important to address IMO is to inspect the rear brakes. Change the front rotors and pads. Bed in an do some good driving around.

Best of luck and hope you can get back on that epic trip.

 

[Artie]

Sounds like a good plan to get back on the road.

From what's described, it maybe a confluence of factors. Between the rear pads breaking in, trailer brakes needing more gain, the fronts got overworked and glazed. Possibly to the point of compromising the whole of the pad material. 14000+ lbs gross is A LOT of rig for stock pads and any issues would not be forgiving at that weight level. With 50k adventure miles on original? rotors with less mass and thermal sink.

Regarding the rear pins, they allow the caliper to float and shouldn't prevent max braking, I think. They should be lightly lubricated rather than packed?

What's important to address IMO is to inspect the rear brakes. Change the front rotors and pads. Bed in an do some good driving around.

Best of luck and hope you can get back on that epic trip.

Agreed, I’m very hopeful it’s a confluence of factors as you described. Either I need to drive this truck more frequently or do these inspections and repairs much earlier before these trips.

Yes, these are all the original components from new, mileage was 53,999 at most recent fuel fill up. The mileage on this truck is 75-80% tow mileage on trips like this, definitely in the hard use category and I’m likely experiencing these brake issues because of our use. I accept that every possible component on this truck will experience a much shortened life cycle.

I definitely didn’t pack the rear pins but I wiped off the old grease and applied new, installed them and wiggled everything around, then torqued to spec. There could be a slight vacuum when pulling them out just given the clearance between the pins and mating channels with the grease but movement shouldn’t be inhibited. I’ll double check these today. I’m just obsessing over any potential issue as I do not want to pull wheels again on this trip. We had alignment issues last trip with a few shop visits and one full day at a dealership, luckily the kids and wife were at the hotel in Moab.…regardless, I’m somewhat scarred from that trip as is my wife.

 

[Sajan]

Agreed, I’m very hopeful it’s a confluence of factors as you described. Either I need to drive this truck more frequently or do these inspections and repairs much earlier before these trips.

Yes, these are all the original components from new, mileage was 53,999 at most recent fuel fill up. The mileage on this truck is 75-80% tow mileage on trips like this, definitely in the hard use category and I’m likely experiencing these brake issues because of our use. I accept that every possible component on this truck will experience a much shortened life cycle.

I definitely didn’t pack the rear pins but I wiped off the old grease and applied new, installed them and wiggled everything around, then torqued to spec. There could be a slight vacuum when pulling them out just given the clearance between the pins and mating channels with the grease but movement shouldn’t be inhibited. I’ll double check these today. I’m just obsessing over any potential issue as I do not want to pull wheels again on this trip. We had alignment issues last trip with a few shop visits and one full day at a dealership, luckily the kids and wife were at the hotel in Moab.…regardless, I’m somewhat scarred from that trip as is my wife.

On the rear pins, you just need to put a little bit of rubber grease. No need to stuff it.
"Apply at least 0.8 g (0.03 oz.) of lithium soap base glycol grease to rear disc brake cylinder slide bush."
What grease are you using? I used the Toyota rubber grease but anything that's compatible with the rubber boot should be fine.

On a diff note, sorry you are having trouble with the brakes. whatever it is, i know it's not fun having to do this when you are supposed to be relaxing. hang in there!

 

[Artie]

On the rear pins, you just need to put a little bit of rubber grease. No need to stuff it.
"Apply at least 0.8 g (0.03 oz.) of lithium soap base glycol grease to rear disc brake cylinder slide bush."
What grease are you using? I used the Toyota rubber grease but anything that's compatible with the rubber boot should be fine.

On a diff note, sorry you are having trouble with the brakes. whatever it is, i know it's not fun having to do this when you are supposed to be relaxing. hang in there!

Thanks for the moral support, it’s definitely welcomed.

This is what I had on hand at the time, I’ve since ordered the correct Toyota stuff. I applied the stuff to the pins only and spread it around to coat the surface, you could see the metal pin color easily, definitely wasn’t packed. I can pull these pins today and clean all this stuff out and apply something else. I looked at a local part store and this was the only option there as well. I don’t know how it compares to the Toyota stuff.

 

[bloc]

Just be sure to give the new brakes 10 miles or so of steady state driving to cool down after bedding before stopping. Wouldn't want to get uneven pad deposits on those new parts.

I know 10 sounds like a lot but I've been surprised how long it took mine to cool adequately after a bedding procedure. Maybe I pushed them too hard during bedding? More likely ours have plenty of mass to cool and won't do so as quickly as a sports car.

 

[Sajan]

Just be sure to give the new brakes 10 miles or so of steady state driving to cool down after bedding before stopping. Wouldn't want to get uneven pad deposits on those new parts.

I know 10 sounds like a lot but I've been surprised how long it took mine to cool adequately after a bedding procedure. Maybe I pushed them too hard during bedding? More likely ours have plenty of mass to cool and won't do so as quickly as a sports car.

the hardest part was finding a stretch of road without cars to do the bedding. good grief...i drove around a lot to find a spot.
i would get to 5 or 6 hard stops and then I see cars coming up...
then you got drive for a while to cool them down...

 

[Artie]

Just be sure to give the new brakes 10 miles or so of steady state driving to cool down after bedding before stopping. Wouldn't want to get uneven pad deposits on those new parts.

I know 10 sounds like a lot but I've been surprised how long it took mine to cool adequately after a bedding procedure. Maybe I pushed them too hard during bedding? More likely ours have plenty of mass to cool and won't do so as quickly as a sports car.

Will do. I can bed in then hit the interstate to cruise at 60-65 for a bit, exits are spaced well to make a few loops offering a good cool down interval before taking a exit. I can do this for a while.

 

[Artie]

the hardest part was finding a stretch of road without cars to do the bedding. good grief...i drove around a lot to find a spot.
i would get to 5 or 6 hard stops and then I see cars coming up...
then you got drive for a while to cool them down...

I’m in Billings and looking at the map it looks like there’s no shortage of middle of nowhere where roads to choose from. I’m sure my garage space host can suggest a good spot.

 

[WreckDiver1321]

I’m in Billings and looking at the map it looks like there’s no shortage of middle of nowhere where roads to choose from. I’m sure my garage space host can suggest a good spot.

I definitely can.

FYI I have Permatex Extreme brake grease on hand, that seems to meet spec.