Aftermarket parts can be a PITA !!

[twincamzz]

Been working on the rear disc brake system on my '61 Panhead the last week or so. It's a '72 - 80 banana caliper. Actually this one started life out as a front caliper... but hey, it works & was there, so I'm going to go with the flow on this one.  The plan was to install new pads & a good used  10" rotor I'd been saving for a few years, a new master cylinder , new caliper pins, & all new lines & seals in the caliper as I am switching over to DOT5 brake fluid.

Once I got it apart I found the piston to be fairly good shape with the exception of the insulator on the piston face. It should protrude from the piston about a 1/16" inch or so I believe. The insulator on mine was just about flush with the face of the piston & the leading edges of the piston were feathered out slightly where the dust seal would ride. Probably feathered out from the insulator being wore out I figured. The pic shows the edges after I ground them down a bit before I decided to just replace the thing.


I found the part I was looking for in one of the mail order catalogs, so I placed my order & waited 3 more days for the piston to arrive via the big brown truck. Finally got it in my hands & saw that there was no insulator included with the piston. A quick call to the catalog's tech guy & I found out that they didn't sell the insulator, and he checked around, turns out nobody he could find did either. So I improvised.

I found a fork truck caliper insulator that was just slighly bigger than needed & a friend turned it down, pressed it in the piston, then faced it off for me. That's it in the pic beside the old piston. Problem solved. I couldn't wait to get home & assemble my freshly rebuilt caliper. Boy did I feel silly when I dropped it in the hole only to watch it go about 1/2 inch & stop. Dammit. What now. Turns out the bottom aluminum ring right below where the big o-ring would go was .007 too big. Another trip to see my friend, a quick turn on the lathe & all was well.

While I had it apart I also used JB Weld to fill in the egg shaped caliper pin holes & redrilled them for a good as new fit. Also replaced all the bushings in the boomerang caliper mount & made a new pin for the mount that goes all the way through both sides of the caliper. Still waiting on another fitting as I ordered the wrong one the last time. Once that arrives I'll finally get to check this project off the list & move on to something else.


Okay, that's my rant on aftermarket parts.   I realize this isn't the last time something like this is gonna happen during this ol gal's rebuild. I just hope thy're all this simple to fix. That & luck on my side & I'll be good to go. Hopefully. lol.

[ModelABob]

twincamzz,

Dude, I use the exact same set up on the rear of my '65 Pan!  Back in the day (early 80's) this was the way to go for up grading the 'ol Pan binders.  I also switched to DOT-5 many years ago too.  Before I switched I asked around about compatibility of the rubber o-rings, seals, etc.  Nobody could give me a definite answer, but I've only had to replace the caliper rubber parts once in 15 years or more.  On the banana caliper half's where the main support pin goes.  I had a friend machine out the holes and press 65A generator end needle bearings into each half.  The support pin ends have to be shortened a speck, but everything fits nice and tight and I never have to worry about the caliper half's wearing out.  The set up might not be as cool (or expensive!) as the new "14 piston, triple-diple plunger, with outer atmosphere floating halographic disc" systems, but they work.....'nough said!

AMF/Ride & Shoot Safe