Alanf’s blog…
Scattered thoughts

Tuesday, November 30, 2004

Box of Shame #1: EZ Outs aren\’t always easy…

Author: site admin
Category: The Box Of Shame

I’ve been riding, and wrenching, on bikes for a long time now. This has led to a lot of “learning experiences” and those have sometimes resulted in broken parts or repair bills. I keep a “box of shame” in my garage, containing worn/broken parts, as a reminder of the lessons I learned during those moments.

I decided it would make for an entertaining series of blog entries if I related some of those tales.

I bought my ‘88 GSXR1100 in ‘91 from a race team after it had survived three hard years of endurance racing. Thus I was given a head-start on the educational experience that is bike repair. I learned a lot quickly, especially things like fairing repair, replacing worn/bent parts and daily lessons in metal fatigue. By 1993, the bike had 20,000 street miles on it and most of the niggling problems from the race days were over.

However, after a weekend street ride, I discovered that the end of one of the front left brake caliper bleed nipples had broken off. I don’t know if this was because it got hit by a stone or whether vibration caused it to crack but the end result was having the shaft of the bleed nipple stuck in the caliper with no obvious way to remove it.

Since I’d worked on old cars before, I knew the solution. I headed up to the hardware store for a set of EZ-outs - reverse threaded studs which can be inserted into a hole then turned to extract the bolt. Normally, a drill bit and a T-handle tap wrench are required bit in this case the bleed nipple was already hollow so no drilling was required. I figured I’d just use a crescent wrench and save the $10 for the T-handle.

Big mistake. The T-handle allows you to apply constant, even pressure while turning the EZ-out. A crescent wrench, on the other hand, causes a twisting and bending motion. Additionally using a big f’ing crescent wrench can create enough torque to snap off the end of the EZ-out inside the bolt you are trying extract. In addition to causing a lot of cussing, this also expands the bleed nipple enough that it won’t ever come out again. Care to guess how I discovered this information?

The cooked caliper

To make matters worse, I brought the brake caliper to a local shop to see if they could help. They tried to use a cutting torch to get things to expand but overheated the thing, basically welding the bleed nipple in place. To fix that, they drilled out the nipple but drilled too deep, scoring the “dished” portion inside the caliper which allows the bottom of the bleed nipple to seal when tightened down. To fix that, they milled off 4mm from the top of the caliper but that resulted in too little thread contact on the shaft of the bleed nipple to prevent leaking. By the time I got the caliper back, it was discolored from the torch, required teflon tape to prevent brake fluid from leaking out and had a huge flat spot from the milling machine. Soon after, the brake piston seals on that caliper failed, possibly because they too had been overheated by the torch.

I eventually bought a used caliper to replace the damaged one and thus started my box of shame.

Needless to say, I should have sprung for the $10 T-handle in the first place…

2 Comments so far

1.

JKarp
December 1st, 2004 at 5:58 am

Chuck EZ-outs in a torque adjustable cordless drill (or better, an impact driver if you’ve got one). Learned that one the hard way went I spent 2 full days just removing the rear springs off the Jeep and 3 of the bolts sheared right off in the frame.

2.

Alanf
December 17th, 2004 at 5:24 pm

Right after I screwed up that caliber bleed screw, I sprung for the T-handle had haven’t had a problem since. In fact, I’m often amazed at how easy E-Z outs work when using the T-handle, versus trying to turn them with a wrench.

The drill idea sounds interesting but I’d use a really low torque setting and work really hard to keep the drill perfectly in line with the E-Z out to keep the twisting movement inline with the screw.

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