A truck and trailer thread.

[McMXi]

That is some strange marking on those rotors. Is pad material coming off the pads I have seen that happen. In all my years around heavy duty disc brakes I have never seen that much slop between the wheel studs and rotors. I would wonder if some of those Fords have different sized wheel studs. Its been a long time since I have had to put a set of rotors on a ford super duty. My super duty doesn't have that kind of slop. Even my semi grain trailers with disk brakes don't have that kind of slop between the rotor and stud. I wonder if they didn't sent you the wrong rotors. I would also check all your bushings on your front axle to make sure its not moving when your braking and making a noise. I have had that happen on the super duty's with some miles on them the bushings wear out.

I can't feel any material on the rotors so if the pad material is coming off it's depositing in a very even manner. One of the reasons I ordered new torque wrenches today is that I'm wondering if it's a wheel lug nut torque issue. The Ford spec is 150 lb-ft to 165 lb-ft and I remember setting the torque wrench (which broke yesterday) to 150 lb-ft. I went into town yesterday and had one or maybe two soft "thumps" when braking. Not immediately when braking but at some point in the process. It's plausible that the rotor it moving under braking but I'm not sure.

Once I can torque the lug nuts with some confidence that they're in spec, if the thump persists I'll look at other things such as the bushings and any other related parts.

Thanks.

 

[Lil Foot]

I had a somewhat similar issue with a '99 LHS.
Out of nowhere it developed a sort of intermittent thumping noise when braking, but it was accompanied by a brake pedal pulse & you could feel it in the steering wheel also.

Turns out a plastic grocery bag had gotten lodged on the caliper/rotor and melted from brake heat, bleeding out plastic residue from the rotor holes/slots when the brakes got hot enough, apparently causing either a sticky spot or a slippery spot.

My mechanic tried to clean it, but finally had to replace that brake setup,

 

[armylifer]

You might try backing up and braking hard. Then try going forward again and braking a little hard and see if the thump happens again. My theory is that if the thump can be replicated in this manner that the slop in the disk is probably causing the thump. I think it is worth a try anyway. What have you got to lose by trying that?

 

[McMXi]

You might try backing up and braking hard. Then try going forward again and braking a little hard and see if the thump happens again. My theory is that if the thump can be replicated in this manner that the slop in the disk is probably causing the thump. I think it is worth a try anyway. What have you got to lose by trying that?

I had that same thought and figured it was my reversing/braking that rotates the rotor one direction, and then at some point it rotates the other way and "thumps" and remains there until I reverse and brake again. Are the holes in the rotor oversized, maybe. Is the lug nut torque in spec, maybe. I can verify the latter next week when the new torque wrenches show up.

I replaced the windshield washer nozzles last night and just about froze my hands in the process. It's incredibly annoying and dangerous to drive around with ineffective or inoperative windshield washer nozzles. $5 per nozzle and $5 shipping from RockAuto got it done.

 

[McMXi]

I guess you get what you pay for. I tested the Dorman windshield washer nozzle this morning and the pattern isn't good at all. Way too low compared to the factory one on the passenger side. I tried to take a photo of the pattern but not easy to do while driving. I called the local Ford dealer and they had two nozzles in stock and it was $48.60 for the pair!!!!

I compared both using a loop and the difference is very apparent. The difference in quality of the injection molding is obvious, not to mention the geometry difference for the part that controls the pattern. I guess I wasted $15 buying Dorman crap from RockAuto. I bet Ford's cost on that nozzle is around $0.10 each but it's a serious safety feature i.e. having the ability to properly clean the windshield, so what is one to do other than pay the man.

A .50 BMG case works well to hold the nozzle for close up photography work!

 

[McMXi]

You might try backing up and braking hard. Then try going forward again and braking a little hard and see if the thump happens again. My theory is that if the thump can be replicated in this manner that the slop in the disk is probably causing the thump. I think it is worth a try anyway. What have you got to lose by trying that?

After today's test drive to town I'm more and more convinced that the rotor is rotating relative to the hub and causing the thump. I heard it today while backing up, then it happened again the first time I braked moving forward after I'd backed up, and then didn't happen again (I didn't back up after that) despite some braking with a lead foot to test out the hypothesis.

 

[armylifer]

After today's test drive to town I'm more and more convinced that the rotor is rotating relative to the hub and causing the thump. I heard it today while backing up, then it happened again the first time I braked moving forward after I'd backed up, and then didn't happen again (I didn't back up after that) despite some braking with a lead foot to test out the hypothesis.

It sounds very much like the slop in the brake disks are at fault. I am thinking that you were given the wrong brake disks when you replaced them. Did you replace the old ones because they were compromised or was the reason just because you were in there already? If you still have the old disks, can you take a inside caliper and measure the diameter of the lug holes on the old ones compared to the new ones? If the hole size is different maybe consider talking with the place you bought them from for a replacement. I think I read earlier that you got them from NAPA. Our local NAPA dealer is pretty good about making things right if they made a mistake. Maybe yours will too, if they gave you the wrong part.

 

[McMXi]

It sounds very much like the slop in the brake disks are at fault. I am thinking that you were given the wrong brake disks when you replaced them. Did you replace the old ones because they were compromised or was the reason just because you were in there already? If you still have the old disks, can you take a inside caliper and measure the diameter of the lug holes on the old ones compared to the new ones? If the hole size is different maybe consider talking with the place you bought them from for a replacement. I think I read earlier that you got them from NAPA. Our local NAPA dealer is pretty good about making things right if they made a mistake. Maybe yours will too, if they gave you the wrong part.

The rotors and pads are from Power Stop. I would expect the holes in the rotors to match the holes in the wheels. There is a bit of play of the wheel on the lugs so maybe clamping force is what prevents this sort of thing. I'll know more next week.

I just replaced the Dorman windshield washer nozzle with the Ford part and it's night and day difference. The spray pattern is as it should be and the nozzle fits in the cowling better too. The last photo shows the spray pattern from the Dorman nozzle which barely gets above the bottom half of the windshield. I'll email RockAuto with photos and tell them that they're selling junk parts and see if they respond. Another example of the aftermarket doing a junk job of making "equivalent" parts.

 

[biketopia]

Unless your wheels are very loose, I'm not fully convinced your rotors are moving; the holes look normal. We have a fleet of over 200 SuperDutys and I have been doing breaks on them for 20 years. I don't see anything abnormal, are there witness marks on the threads of the wheel studs? I'd be investigating bushings, leaf-spring hangers, u-bolts, and even ball joints.

 

[The Evil Twin]

One issue I need to address with the F-250 is an intermittent soft "thump" when braking, and thought it was something in the DECKED drawer system sliding around. But after removing various things and realizing that I can feel the thump in the floor of the truck, I figured it has to be something related to the brakes themselves. I'm not able to reproduce the "thump" on demand and it seems random enough that I haven't been that concerned about it.

Last year I replaced all four rotors and all sets of pads using Power Stop products, and even replaced the front calipers with Ford remans from NAPA. This was done around 5,000 miles ago with no issues until recently. Around 4,000 miles ago I replaced all the soft brake lines too with teflon lined stainless steel hoses and flushed all brake fluid and power steering fluid and bled all the systems. The brakes were the best they've ever been and still seem to work well.

This afternoon in 20°F weather I removed the front driver's side wheel and looked around. I've done too many brake jobs to count over the years and have replaced many sets of rotors and pads, but I can't remember if the "slop" of the rotor over the wheel studs is normal. I can spin the hub and the studs will move in the rotor holes and I show the two extremes below. So now I'm wondering if the rotor is moving during breaking, not always but sometimes. I should have checked the lug nut torque values but forgot to do that. The spec is around 150 lb-ft and it would make sense that the rotor could rotate relative to the studs if the torque wasn't high enough since it's clamping force that prevents the rotor from slipping if the holes are oversized. Does this amount of play of the rotor on the hub seem normal or are the holes oversized?

Another thing I noticed is that there's some weird smudging on the rotor but I can't feel it at all. It looks like I should be able to feel it but it's silky smooth.

View attachment 168837

View attachment 168838

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Can't say I ever recall seeing wear patterns like that.

 

[McMXi]

Unless your wheels are very loose, I'm not fully convinced your rotors are moving; the holes look normal. We have a fleet of over 200 SuperDutys and I have been doing breaks on them for 20 years. I don't see anything abnormal, are there witness marks on the threads of the wheel studs? I'd be investigating bushings, leaf-spring hangers, u-bolts, and even ball joints.

I'll figure it out, but these things aren't much fun to figure out when it's really cold out. Problems seem to like to show up at the worst times.

 

[McMXi]

I helped my neighbor hook up his truck to my Kaufman trailer this morning. He doesn't have a gooseneck hitch so is borrowing my B&W set. I'm not loving how he chained his truck down but the front suspension is coil over with control arms so not the easiest to work with. His older Chevy probably has a cracked head so it's off for a two-week visit to a local diesel shop.

I showed him the two new Mytee Products binders that I bought a few months ago but he was skeptical about taking the tension off them to release them so didn't use them. I was hoping I'd get to see them in action but I guess I'll have to wait until I haul tractors around this spring.

By the way, he recently got his truck wrapped and I'm impressed with the thickness of the wrap and the overall quality of the application.

 

[McMXi]

To all those doubtful that the soft thump when braking was due to a rotor turning on the hub .... you get a gold star! I checked the lug nuts this morning with the new TEKTON torque wrench set to 159 lb-ft and all 32 were fine. A trip to town revealed the soft thump to still be there.

Looks like I have some investigating to do. Overall though the truck is driving very well, and the new VisionX lights will be here on Thursday.

 

[armylifer]

To all those doubtful that the soft thump when braking was due to a rotor turning on the hub .... you get a gold star! I checked the lug nuts this morning with the new TEKTON torque wrench set to 159 lb-ft and all 32 were fine. A trip to town revealed the soft thump to still be there.

Looks like I have some investigating to do. Overall though the truck is driving very well, and the new VisionX lights will be here on Thursday.

I was going to hold off on this suggestion until I heard back from you on tightening the lug nuts. Now I am wondering if it could be one of the brake calipers.

 

[McMXi]

I was going to hold off on this suggestion until I heard back from you on tightening the lug nuts. Now I am wondering if it could be one of the brake calipers.

I installed refurbished brake calipers (Motorcraft from NAPA) and made sure to grease the caliper pins. There was mention of ball joints and I bought MOOG ball joints a few years ago with the idea to swap out the original ones. This is the time when I really wish I had a lift at home. It's much easier to push, pull and pry on suspension components when the vehicle is up on a lift.

I'll look at the sway bar, leaf spring u-bolts, shocks and more as well as the calipers. Something is causing the intermittent soft thump which is more annoying than anything. I like things to work properly and clearly this isn't the case. I had hoped it was the DECKED drawer system that was moving fore/aft. I noticed last year that the front mounts inside the front "ammo cans" were broken and reached out to DECKED who sent me upgraded parts at no cost. I bought the drawer system in July of 2019 so it was very good of DECKED to take care of me with replacement parts. I haven't replaced the mounts yet so it could be that, but I feel the "thump" low down in the floor of the cab.

I'll update once I've figured it out.