Thursday, May 29, 2008

Waiting too long to replace the front brake pads

So I'd been hearing a pretty loud rubbing sound the last couple of days when activating the brakes while at low/crawl speeds. The brakes seemed to work fine so I kept forgetting to take a closer look. Apparently, I'd been too careless in checking the wear on the front brake pads as they were pretty much out of the ablative material and it was the actual metal backing of the pads themselves that was in contact with my front brake discs!

Yep, stupid....careless, yep that's me. Now I know you have to really get closeup and peer into each caliper to look for the evidence of wear marks on the pads. I could kick myself, I knew better! I blame my aging eyes, I have to remove my glasses to do any kind of closeup work these days.

So, I discover all this last night after supper so I thought: hey, I've still got the old pads that have some wear on them....I'll swap them out now and order some new pads in the morning!

Only one major problem while doing the swap of the pads, I stripped the Torx screw portion of the pin that holds the brake pads in place within the left caliper! Aaaarrrggghhhh! Hours later and having tried other sized Torx wrenches and whatnot, I remembered I'd bought a stripped screw extractor kit from Harborfreight!

Ended up using extractors 1 thru 3 in progression

After some searching, I found it, and learned how to use it for the first time. I had to call a friend of mine who actually had done this and he walked me through the process (thanks Rob!). Took a few attempts and gradually increasing the size of the extractor before I got it to engage in the hole I'd drilled into the stripped Torx screw! What a pain this was. Not to mention, I did not have a good tool to hold onto the square end of the extractor and had to resort to vise grips! I must find something that will do a better job.

Finally, the motorcycling wrenching god took pity on me and the extractor not only gripped but I was able to break the tight grip the pin had on the caliper housing! Out the sucker came and promptly broke off in my hand. I am so glad it did not break off within the caliper housing!

The brake pad retaining pin, what a pain it was to remove!!!

You can see the hole I drilled for the use of the extractors

Of course, the front brake discs now have very slight but noticeable by feel grooves worn into them by the pads which I allowed to wear down too much! I'd been monitoring the thickness of the discs anyways since the were down to 5mm in thickness and would be out of spec at 4.5 mm. So replacing them had been on the mid-to-far maintenance horizon, now they're in the "do it now" maintenance window!

I've got a pair on order for the front, the back disc is fine. They should be here in a few days and I'll swap them out at that time and put brand new brake pads in then. No sense putting new pads in on brake discs that are "worse for the wear" eh?

I got the kit to replace the brake pad retaining pin and put it in today. Got a new set of Torx socket drivers and torqued the caliper retaining screws to spec as well. I did NOT overtighten the new brake pad retaining pin, relying instead as the designers did I am assuming, on the spring preventing it from working itself out.

The circled item above is the wear mark I failed to monitor closely during weekly checks
The arrow shows how little material remains on the old pads I reinstalled. So Check yours now and make sure they're not as close together as mine are!

A good view of the new brake pad retaining pin, nice and shiny, note the retaining spring

Too thin to try and "turn" to smooth them out, must buy new ones.

Trying to see the silver lining to all this:

I learned that one can't be too quick when doing maintenance checks. In other words, do it right and often or pay the piper.

I learned how to use a screw extractor tool. I am sure there are further stripped screws/fasteners in my future, it'll happen again.

I did not learn about the worn down pads and brake disc after they failed me during a stop, so no one got hurt, specially me.

If you replace pads, and the old ones still have some life in them, keep them around. You never know when they might come in handy.

So, don't just sit there, go out there and see how much wear is left on your own brake pads! The price is high for not watching them closely. I got 13k out of the old pads, will probably just swap them out regularly at 10K or so from now on.

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