See, this is what happens when you don’t inspect your brakes THOROUGHLY.
I’ve been slacking, Oppo. It’s bad enough that the ’Murlequin’s horribly worn motor mounts escaped my notice, but holy crap these brakes! Yeah my sister’s had gotten pretty bad, but I have no excuse either.
The closest thing I have to offer in the way of excuses is that my brakes felt “adequate” (though probably in sore need of an upgrade), and seemed to pass a half-ass visual inspection. There appeared to be a fairly substantial amount of pad contact, but I failed to notice just how large the pads were, and how much more contact with the rotor there actually should have been.
But as critical as pad-rotor contact is, it paled in comparison to the condition of the rotor vanes.
There’s almost nothing there! So much rust had eaten away at the vanes, surely they were on the edge of failure (the driver’s side a little more so than the other). Could they be the original rotors? With the truck at nearly 300,000 miles, I’ll grant that there’s a chance that they might have been replaced ONCE. Maybe. But it would have been a long time ago.
I didn’t even need to put calipers (I mean measuring calipers- dang it, why we gotta use the same word for parts and tools?) on it to tell that they were beyond hope of resurfacing.
I’ll give the previous owner(s) this, though- the bearings were well greased and in like-new condition. I’m not reusing them, but someone had definitely kept up on them.
If I had to guess, I’d say that whoever did these brakes last was wise enough to regrease (or replace) the bearings, yet slacked off when it came to the actual condition of the rotors. Maybe they tried to get them resurfaced, and the machinist declined? ...and instead of buying new rotors (approx $50-$75 a pop at local parts stores), they just did a pad-slap? I did find a fair amount of material still remaining on the pads (7mm on both outer pads, 4mm on the inners).
I do know that the brake calipers had been replaced at some point in recent years, due to a much lighter coat of rust than the rest of the undercarriage. Maybe somebody just happened to hit their budget limit. Oh well. Doesn’t matter now. I’m doing a complete job- pads, rotors, bearings & grease seals, cotter pins, and fresh fluid.
I picked up my parts and got to work. Packed the fresh (National) bearings with my new favorite grease: Red Line CV-2, as suggested by His Stigness. This stuff is so slippery, and so sticky, I couldn’t wipe it off of my gloves. Had to change into a new pair in order to continue working, or risk getting grease on everything else.
I even went as far as to pop the new races out of the rotors so that I could press in the ones that came with the bearings, to ensure a perfect match.
But after installing the first rotor, I heard scraping as I spun it. Bent dust shield? No, not exactly...
See that plastic ring? That’s the wheel speed sensor for the ABS. It was grinding against the new rotor, and had surely been doing the same to the old one. And why was it even making contact at all?
Rust jacking. Rust had been flaking up and pushing the dust shield away from the steering knuckle, pressing the sensor ring closer and closer towards the rotor.
So I pulled the sensor and shield assembly off, cleaned up the rust, flexed the shield back into a more stock-like shape, and put it all back together. Plenty of clearance now. And the sensor’s not damaged enough to affect operation, so I say send it!
(Oh, and by the way, as an update to this post, the cheapest brake cleaner option I’ve been able to find is at Menards: comes to about $0.13/oz.)
To complete the job, I pushed some fresh brake fluid through the lines. The fluid wasn’t nearly as bad as when I had replaced it a couple of years ago upon buying the truck. But this was a good time to do it anyway.
You know what, maybe I won’t be upgrading these brakes after all. It sure does stop a lot better now.