front end clunk and hard brake pedal

I believe its coming from lca bushing. How hard are these to change and during troubleshooting i have an issue with brakes if i tap the brakes 5-8 times real quick the pedal get very hard not sure what to look for on this

Short answer is: Don't do that with the brakes.

If you were using a gasoline engine there'd be an inexhaustible supply of booster vacuum. With a diesel it relies on a pump. A pump that isn't sized to compensate for pulsing the brake pedal like that.

Yes i only did the brake tap while trying to figure out the lower control arm noise so it caught me by suprise

The clunk could also be the sway bar bushings. Incredibly easy to change and really cheap. Doing the lower control arm bushings is definitely more time consuming the sway bar bushings but doable for a novice. There are how tos on both of them here. I have done both of these repairs when I redid my suspension over the last two weekends.

Well the LCA bushing are a little tired but the noise was coming from a rock stuck between the LCA and the subframe
wayne