Front noise at high speed/pulling right

[Phase 1]

Ok so I’ve been having issues with a combination of pulling to the right, shaking at higher speeds, and a whum whum sound that has a regular rhythm. Been chasing this gremlin for a little while but am getting tired of throwing money at it (more specifically the wife is getting tired of it) and want to start narrowing it down. Any help would be much appreciated guys and gals.


Pertinent negatives:

All front ball joints and control arms have been changed and are properly lubed

Wheels/tires have been rotated and balanced

Brake pads, calipers, hoses, and disks are all evenly worn or new and not catching

Camber and caster are both reasonably aligned


Possible issues:

Alignment was done recently but was “subpar” (toe out on front right) I have addressed it since but it may need additional work

Tires have some wear but have been rotated and no change in symptoms

There are plenty of noises going on with the vehicle but nothing that to my mind would be the cause, that said if you ask I can definitely elaborate on them


Misc info:

99’ Explorer Sport OHV manual trans RWD 128k miles



Edit: The noise starts at roughly 60-65 mph

 

[fast_dave]

My .02 Guess given your X's Age and Milage..
Advice from Easy to Hard:

A) R/F Brake Caliper Pins that the Caliper Slides on have no grease/dried out grease.
Very commonly over looked since 90% of Shops and Home Mechanics never take the caliper pins out, clean off the old grease, and re-grease them with High-Temp Synthetic Brake Caliper Grease. The caliper needs to easily slide back and forth to avoid having the pads "stick" and thus rub against the disc.

B) R/F Brake Caliper Piston is slowly in the process of sticking (closed) due to brake fluid never being changed and the brake piston is rusting into the caliper body
Very common since brake fluid is glycol based and thus is hydroscopic (attracts water) and should be changed/flushed every 2-3 years, but the 80% percentile rarely does this.

Many of today’s brake fluids are made of polyalkylene glycol which is hygroscopic, meaning it absorbs moisture. This can be a good thing and a bad thing. The absorption of water promotes dispersal throughout the braking system and prevents “pooling” of the absorbed water in low-lying areas of the brake system where corrosive acids can form and make the components deteriorate at a faster rate.

What color is the brake fluid in your reservoir? It should be clear, and after a year or two of use it slowly turns amber in color, which is when you should flush/change it. I'm guessing the color of your brake fluid is black.

I'm sure more will chime in - lol!

Good luck!

 

[J_C]

Alignment was done recently but was “subpar” (toe out on front right) I have addressed it since but it may need additional work

That's definitely something I'd take another look at.

 

[CDW6212R]

When were the rotors last taken off? The 2WD wheel bearings can often end up too loose after installation. To check them, lift the tire off of the ground, and by hand top and bottom, see how much it rocks in and out. It should barely, barely move, loose bearings will create lots of heat and damage the bearings and races, eventually galling and grinding etc, pulling is a common symptom from that.

Be sure the caliper bracket bolts are very tight, those are big bolts that should be lugnut tight. The caliper bolts are small, and have no exposed greased parts, they have internal and sealed pin shafts, no need to ever remove those(for many year at a time).

Check the sway bar end links, broken they can create odd handling. Keep hunting, you will find it soon.

 

[Mbrooks420]

A whum whum whum sound with good tires sounds like wheel bearings to me.

 

[Phase 1]

Thanks for all the reply guys! So in order of posting I went ahead and got another set of caliper pins to put in sometime this week. I've been keeping the brake fluid fresh since I've owned the vehicle and just did a flush about 2 weeks back so I don't think that's it. Now as far as rotors and wheel bearings, the wheel bearings were done about 2 years back and checked them out myself this last weekend and they look clean, well lubricated, no excess play and wheel turns freely. The sway bark link ends we're just replaced maybe 6 months ago and I'll be replacing the sway bar bushing this week as well when I'm doing the caliper pins. I'll keep yall posted!

 

[J_C]

Am I missing something? I mean I don't recall buying caliper pins for anything. If they are corroded I just sand down to somewhat polished and relube with thick silicone paste (Raybestos, 3M, etc) which tends to last *forever*, even in my winter salted road environment.

 

[bigred4x4]

I had wheel bearings go bad in a two wheel drive ex and it squeaked and chirped real bad and one time it even came apart and left me on the side of the road because I wheeled it I had to repack them pretty regularly , on a 4wd when the hubs went bad it sounded like I was suddenly driving on boggers and hummed real bad.

My 2wd did those exact things you speak of I'd check those bearings again maybe the spindle nut. Can only really be that or brake related

 

[Phase 1]

Sorry for the long reply again guys. Got the work done and been driving on it to see the results. Did some extra adjustment on the alignment and that helped tremendously. Also swapped the caliper pins on the right side and found the old ones were binding. Took away maybe 8o% of the noise. Did find that the rotor was catching some so maybe heading that direction next. Also took another look at the wheel bearings for kicks and they’re still packed and clean. Look as new as when they got put in.

 

[CDW6212R]

The "caliper pins" in the 2nd gen Explorers are the small bolts that hold the calipers together. Those should not really need to ever be replaced. The pins and the mating holes of the caliper that they ride in, any wear of one will affect the other. If there is ever any suspicion of wear of one pin(there are two per caliper), the entire caliper and pins should be replaced.

At the age these trucks are at, and for any vehicle pushing over 15 years old, certain parts become main concerns which were no concern before. For a new car, you should never have to worry about parts like calipers, door hinges, body mounts etc, countless parts. But age makes a huge difference on things like calipers etc. You cannot depend on old parts to last forever, and certain critical parts like brakes should be a priority.

I'm simply saying, if you have any possible issue with brakes, any hint, inspect very carefully, and replace anything that seems not ideal.

That's part of why I don't ever remove the caliper pins, the sealed type with a boot on it. The old 1st gen trucks have unsealed pins, which are wear items, very well made, but the calipers still do wear from them. The newer style with the sealed pins, those should be left untouched(do not remove them or clean them). If you open up the boot, the dirt can get in, which is what wears out the pins and calipers(people get rushed doing brakes, impatient, and less clean or careful).

What you will find with older cars, buying rebuilt calipers, or any part, the core they rebuilt may be as bad as what you are trying to replace. You cannot any longer buy good rebuilt racks for Fox Mustangs, the rebuilt units are a crap shoot to get a good one. Don't expect rebuilt parts to be the answer forever, take better care of the parts you have.

 

[Mbrooks420]

I disagree on the pins. I pull them and clean them anytime I have the caliper off. They are always dry/dirty. Very easy to clean them AND the boots, and grease with something high temp.

 

[CDW6212R]

I disagree on the pins. I pull them and clean them anytime I have the caliper off. They are always dry/dirty. Very easy to clean them AND the boots, and grease with something high temp.

If you do a great job of R&Ring them, fine, but most people have filthy hands while working on brakes. Most people won't wipe their hands really clean before handling critical greased parts like those pins and the boots. They do it quickly as a normal part of the job, wipe off the pins and boots with a rag etc, and fish out some new grease with a finger, slap it in, and put it back together. It's best to assume people will be a bit messy, and that's when the grease gets contaminated.

Every caliper I've had apart(the pin/boot area), they've all had plenty of grease in them. That's maybe 12-16 calipers. The first thing that happens is the grease is immediately dirty, from the boot being slipped off, the dirt on the outside is quickly in the greased area of the boot and pin. Then it has to be taken fully apart and wiped clean, and repacked. If you remove just the two main large caliper bolts, the caliper pins and boots stay as they are, intact, unopened, and no dirt gets inside. I did my LF two days ago, from an outer pad wearing unevenly along the outer edge(very odd). I put two used pads on it until I get new pads(today). I didn't touch those pins, and when I put new pads and rotors on today, they will still be sealed. I have no uneven wear, none of my vehicles has had, since I work on them. My rears both wore very fast(set of pads in 15k miles), so had to buy rebuilt calipers. Now they are wearing normally, should last a normal time now.

 

[Mbrooks420]

I've never checked them and had them clean, or very well greased. In fact, several times they have been fairly rusty depending in how long it had been. The fact that people are pigs, and can't properly wash their hands (or wear gloves, which is much better) isn't a valid reason to neglect greasing something as effortless as a slide pin. The boots can easily be washed in a sink to total cleanliness, along with your hands. Some fresh grease, and you're safety back in business with no real risk of contamination.

 

[CDW6212R]

The handful of vehicles I've owned haven't had much neglect by previous owners. I know how to discover neglect, and I fix that. But the cars I've owned have been fairly well cared for, and I take great care of them myself. I see no reason to spend or waste time on anything that I know is fine. I'll continue to expect people to do the right thing, but be ready for the worst. Regards,

 

[Mbrooks420]

Nothing to do with neglect. I owned my last Mounty a dozen years. It had new (not rebuilt) calipers installed, along with all new hardware. Caliper slide pins were still not clean and well greased after being on for a year. If you can't properly grease something without pushing in a bunch of dirt, you very much deserve the own problems you've caused, and have zero business touching brakes.

They are your side pins, you can save the time and never grease them. I'm just advising others that it is easy, and possibly worth it to spend, or waste, the 10 minutes it takes for the peace of mind that something is properly greased and taken care of.

 

[CDW6212R]

We agree that many others don't do car work very well. I suggest they(them not you or me) leave those pins untouched, because they will create more problems than not. I could spend the time R&Ring the grease, but it's not needed for me, since I know what's there is clean and adequate.

I have two trucks with custom brakes, and about to redesign those. Many aftermarket calipers a lot of the time have no street seals, the piston seals are simple internal square o-rings. That kind of caliper needs(requires) careful care and cleaning each time they come off. Material builds up behind the SS hardware that the pads ride in, plus the piston seal areas need to be very clean. Those take a lot of extra time to service, I don't suggest anyone not fastidious ever work on those. I haven't had any leak of those, but I worry about it with street use. The new pads won't go in often if you don't R&R the SS hardware and clean behind them. OEM calipers are relatively very well designed and reliable.