Bad clunking from rear end, lost brake pressure

Hey all,

Experienced terrible clunking from the rear end that only seemed to get worse over a couple hours. Smelled something burning from the rear when stopped. Was out of service so I was forced to drive it around 60 miles. Not a good time.

Going to check the usual driveline stuff (u joints, slip yoke, diff fluid). Prepared to get a new diff.

What I'm asking about is the fact that I suddenly lost brake pressure and the ABS light came on right as this started happening. This might be a coincidence, but this post: makes me think they could be related. What are the chances of them happening at the exact same time? I should note that I've had an ABS engagement issue (repeatedly engages when slowing to a stop) for a while now that I isolated to the left rear wheel speed sensor. Just been ignoring it to be honest, did not think it could be indicative of larger issues.

Should I check the rear brakes first? Could it be another issue entirely not related to the driveline? Guessing I'll have to check anyways, but I'm wondering if anyone else has had an issue like this.

I had a 4x4 shop give me the go-ahead on everything suspension and driveline related less than 2k ago...should've checked myself.

2001 4x4 Limited w/ 275k

 

How much fluid is in your brake MC reservoir?

Do you see any leakage of fluid at the bleeders on the backside of the drum?

Is rust a factor at play here?

 

Zero brake fluid, found a bent bracket and damaged brake line behind the rear driver side wheel (not sure if the source of the leak, but seems probable). However that happened probably caused the damage to the wheel speed sensor as well.

Any idea about the connection to the rear end noise/differential?

Rust is not a factor as far as I can tell, west coast truck. Minor surface rust.

 

Is the clunking cyclic, like with each turn of the wheel? Or random? If random I would think maybe zero pressure caliper rattling around? Might not be as bad as you think. Hard to believe you destroyed a brake line and the diff died at the same time. Long story short, look at what you KNOW is damaged first.

 

You might be onto something. It was random and would be worse on take off and coming to a stop, but it seemed that as long as I kept constant acceleration, it would not clunk. That would explain the smell too, but it was such a bad clunk I didn't realize could come from a caliper.

I'm going to repair the damaged line/wheel speed sensor and replace the fluid. Hopefully driving 60 miles without brake fluid didn't completely destroy the caliper.