Vibration at highway speeds that disapears after a few hard brakes

Hi all,
I have a 2017 Tacoma TRD Sport with 6ft bed.
Truck sat in a driveway for about 3 weeks and now when driving at highway speeds it has a vibration at the steering wheel that goes away after i brake hard a few times. Also the vibration changes when i drive at 4H, now it feels like the whole truck is shacking but the same thing happens, it goes away after a few hard brakes.
I replaced my rotors and brake pads about 4 month ago so maybe the rotors are warped cant think about anything else but at the same time there is no vibration at the brake pedal when i brake.
Does anybody had or have similar problem ?

 

Is it cold where you live? Tires get out of round a bit when sitting in cold.

 

Im from NY, today it was 31F.

 

Drive it a few times in a row after a few days. Report back.

 

My '06 TRD OR AC, when driven at highway speeds after sitting overnight, always experienced a bit of vibration from 'flat' spots on the tires. Always went away after a few highway miles warmed up the tires.

 

I have no idea why it would go away after braking, but my first thought when I have vibration at hiway speeds (in the steering wheel and/or stick shift) is out-of-balance wheels. It possible that some ice formed in your wheels while it was parked? Is there a possibility that mud got into the wheels prior to parking it? You should be able to inspect wheels and rule this in or out easily. If there is any in there, take it to a manual car wash and pressure wash the wheels. I go through this process on a regular basis, but it's because I take mine off-road a lot.

 

Start small. check the lug nuts. Some may have been loose or improperly torqued.

 

was the truck hot when you parked it initially, and you parked it with the wheels turned? That could possibly have warped the rotors.

 

?????????

 

We have snow here in NY, and thats what i thought but nope no mud or ice or snow build ups.

Also the truck was parked outside, overnight for 12 hours in 29°F, drove it home and no vibration...it comes and goes like a ghost but def comes after the truck is parked for a day or 2...i am going to check the lug nuts although i did torque it to specs after replacing the rotors. Also if it keeps happening im going to rotate the wheels and do wheel alignment. Will update......

 

I'd go with what @hiPSI said. The longer a vehicle sits, the more pronounced tire flat spots can be. Cold temps, certain tires, and lower pressures will make them worse. They go away when the tires warm up and flex. The time that you are parked at work is not long enough for them to develop.

To test, add a few PSI to each tire from where you are at now. This will not affect anything much at all, but if the issue decreases, then flat spotting is the issue.


Interestingly, the tires that I have now would flat spot in the cold when they were new. I've been expecting it to come back this winter, but nothing.

 

rotor rust!

 

I had 2 diff end vehicles that did same thing
Both times had front tires rebalanced and it went away maybe you lost a tire wieght
Could be flat spots like others have said because of cold

 

I agree probably rust on the rotor. That's why it stops after braking a few times.

 

Update
Checked the lugs, everything is tight.
Second day driving no vibration
I guess its either a flat spot on the tire or rust build up on the rotors.
Thank you for the responses