"Clunk" when hard braking

[Broke(n)]

I just noticed this the other day. The guy in front of me must have seen a Unicorn crossing the road because he just STOPPED! Well I had to apply the brakes pretty hard and come to a stop. Upon doing this I noticed a "clunk" just about as I came to a full stop.
So I went home and decided to try it again in case it was just some fluke. I got up to speed and while I did not slam on the brakes, I did a pretty good hard stop. Again, I heard this clunk at almost the stopping point.
Now regular braking is not giving me any issues. Brakes work great and no noises. These are brand new pads and rotors I installed on 04-12, all the way around. Proper bedding was done as well.

I'm trying to figure out if this is a brake issue, maybe caliper, or maybe something else? I hear no "clunks" while driving so assuming this wouldn't be a tie rod or ball joint, but I could be wrong in assuming that. Although I did check those while doing the brakes. I did not notice either being loose. Although I did notice that the boot on both driver and passenger side upper ball joints was torn off, well not all the way but it is torn pretty good. But like I said, I couldn't shake it but a moving vehicle is a lot more force than me just wiggling a tire.

Any ideas?

 

[Onuma]

This can happen when your ball joints are failing. Luckily, they're pretty easy to check.

BTW - If they look like this...they're gone:

 

[Broke(n)]

The boot is definitely torn open on both sides. It all "looks" pretty clean despite that, but that doesn't mean much.
I've never replaced an upper ball joint before and it doesn't appear to be a big deal, but will this require an alignment after replacing them?

 

[Onuma]

I can't say for certain. Some people say yes, some say no. If you leave the control arm in place and press out the ball joint, then maybe not. If you change the control arm(s) out, then you'll most likely need to perform an alignment.

I recommend getting a ball joint with a grease fitting, so you don't have to do this again for a long time. Greasing them up will help flush the junk out, keeping it doing what it needs to do for longer.

I recently replaced all 4 front control arms w/ ball joints, as well as the coil spring assemblies. On my particular truck it was a PITA...tons and tons of rust. I snapped a few bolts and had a hell of a time. Hopefully, whatever you need to do goes much more smoothly

 

[Broke(n)]

Fortunately this truck was well taken care of and when I did the oil change it looked brand new under there. Everything is in really good condition.
While this might not be my "clunk" issue, it has reminded me that I need to replace those ball joints. I guess getting an alignment isn't a bad thing as I do veer a little to the right every so slightly.

 

[Onuma]

Fortunately this truck was well taken care of and when I did the oil change it looked brand new under there. Everything is in really good condition.
While this might not be my "clunk" issue, it has reminded me that I need to replace those ball joints. I guess getting an alignment isn't a bad thing as I do veer a little to the right every so slightly.

If the upper ball joints are going, you should check the lowers as well just to be safe. The boot being torn or split is the easiest way to tell, of course.

This vid is on an explorer Sport Track, but the premise is the same. He doesn't touch on the lowers though...

 

[Broke(n)]

Well that video just sent me to school! I'm going to have to go out and check the "right way" now. Thanks for that video.

 

[Onuma]

You're welcome! That's what the board is here for I've also learned a ton since visiting here -- the info shared by SeriousX members has literally saved me a few thousand $$$.