Rebushing the Banana.

[Dennman]

A few weeks back, I put 4 short pieces of copper 3/8" line (w/ 5'16" I.D.) in the worn out brake pad pin holes.Three of the 4 bushings were not bad, but; the last one was less than satisfactory.Assembly of the halves was tough. The inserts bound up on the pins.They didn't line up squarely.

Ratman in Vernon has machined up some bushings (for the price of a BEER) to replace these copper ones.
O.D.-15/32"
I.D.-5/16"
Length-11/32"
There will be a .003 press fit with the O.D. machined to 0.472"

I'm in the process of turning an old wore out caliper into a guide for drilling the bushing holes.The first hurdle is to drill 2 parallel holes in the right spot for the size of drill needed for the new pin bushings.

I spent time today stripping the banana of it's riveted-in anchor pin and removing the bonded material from 5 old brake pads.

Stacked the cleaned metal pads up and put the shanks of two 21/64" drill bits through the pin holes.That is a tight fit.Now I bolted the stack together,using the bottom hole in the pads. The hole is 1 of 3 used to hold the bonded braking material from sliding off the backing plate.
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Checked the bits for parallel and placed them in the piston side of the "guide" caliper.The drill bit shanks protrude through the stack (approx. 5/16") to locate in the original pin holes in the "guide" caliper half.Clamped the stack to the caliper half. I'll leave a drill bit in one pin hole.Using the open pin hole, in the stack as a drill guide,I can drill through the caliper half w/ the 21/64" bit.
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After getting the one pilot hole drilled ,I put the bit through it and turned the caliper to drill the other pilot hole.
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Now I bolted the caliper haves together w/ my stack of pads (drill guide) in between.Put one bit shank in one previously drilled pilot hole,through the guide and into the undrilled pin hole.Ran another bit through the open pilot hole,drill guide and back caliper half.Left the bit in that hole and drilled through the other pilot hole and caliper back.Now I have a caliper w/ pilot holes lined up in both halves.I must add that I had two nuts, with the same thickness as the one on the bolt through my drill guide,under the ears on the guide to keep the guide from binding when drilling the back caliper half.I had to drill out the threads in those nuts to allow clearance for the drilling bit.
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Next I have to get a 15/32" drill bit to open the pilot holes up to the insert size (as Hopsing would say,"Chop Chop"

Got two 15/32" bits.Upon closer examination, I realized that my bolted together drill guide had shifted during the previous clamping and the 15/32" drill would have cut through the casting edge below one pin hole.

I took another old brake pad and drilled out one pin hole in it to 15/32".Located the pad w/ the 21/64" bit in the good hole. Clamped this to the piston side of the caliper and relocated the hole to leave some metal around the insert.Drilled the 15/32" through the larger pad hole.Then drilled the other pin hole in the pad to 15/32".Inserted a spare 15/32" bit through the pad and this larger hole in the caliper,clamped it and drilled the second hole.
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If you look close you might see the thin wall below the right new bushing hole.

Then clamped the caliper halves together and drilled through the back half using the holes in the front half for a guide.The caliper is now ready to use as a guide to drill a decent caliper for the bushings.
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The bushing in this pic above were made by ratman in Vernon for the price of a beer.

Spent a bit of time making a modified 15/32" bit for drilling the hole for the bushings.I ground a 5/16" flat on the tip.That'll keep from drilling the center of the bushing hole to deep.I didn't take a pic but it's similar to this one that Jerry made.
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Now back to waiting for Dave's donation to the rebushing saga

[Big Dave]

Dennis i changed my brakes last weekend , did you still want my old Bannana (that didnt sound right) its not in good shape and would need a complete rebuild as it was leaking out the piston so at least a seal and a boot

Dave

[Dennman]

Dennis i changed my brakes last weekend , did you still want my old Bannana (that didnt sound right) its not in good shape and would need a complete rebuild as it was leaking out the piston so at least a seal and a boot

Dave

Sure do Dave! The more parts that I have to work with,the better my attempt to get one that's tight and functions well.I've got all the seals ,boots, pins,bleed nipples and support bushings to rebuild.

[Big Dave]

Will get it on its way saturday

Dave

[Big Dave]

Hey Dennis got called into work today and missed the post office -Sharon will get it out Monday

Dave

[Dennman]

Hey Dennis got called into work today and missed the post office -Sharon will get it out Monday

Dave

OK Dave.I got my brake pad pinhole guide finished today.I'll wait till I have yours before I get to rebushing a caliper.

[kootenai]

got a black caliper denn im not sure if its just a take off and its good ive never run it,if you need it also let me know eh.

[Dennman]

got a black caliper denn im not sure if its just a take off and its good ive never run it,if you need it also let me know eh.

Appreciate the offer Koot.Hope I don't have to take you up on it.I've got a couple calipers to work with.Hoping that I don't totally bugger them up before I get one to my satisfaction.I'm pretty sure I can get the bushing location right on.The depth of the hole will be tricky.

[Big Dave]

On the way ----- didnt know if you had so sent the boomerang - nice shape chrome and the anti rattle spring thingy ( damn im good at tech talk)

It had dot 5 in it and was working but was starting to leak , Have fun

Dave

[Dennman]

On the way ----- didnt know if you had so sent the boomerang - nice shape chrome and the anti rattle spring thingy ( damn im good at tech talk)

It had dot 5 in it and was working but was starting to leak , Have fun

Dave

Great Dave! I run DOT 5 in my masters. That'll make swappin easier once I check out the caliper.
I've got a boomerang on the scoot now.It's been on for ~20+ yrs.I've rebushed it a couple of times but the axle area on it has grooves worn in it from the swingarm.Too many years of armstrong wrenching without a torque wrench.

[Dennman]

On the way ----- didnt know if you had so sent the boomerang - nice shape chrome and the anti rattle spring thingy ( damn im good at tech talk)

It had dot 5 in it and was working but was starting to leak , Have fun

Dave

Got the package today Dave.Great packing job.
When I first looked at the brake pads and saw how evenly they were wore ,I figured that I had a good candidate for rebushing.
After disassembling and checking closely,well, you were right to swap it out to something better.
I can't figure how those pads wore so well with all the pad pin holes and caliper mount to boomerang mount holes so wallowed out.The caliper repair pin that fits in the lower boomerang bushing was wobbly loose.The boomerang as well as the spring support are bent and the boomerang has what looks like severe disc wear on that same lower caliper bushing boss.The piston,which is actually intended for a front aplication,has seen some heavy pounding on the exposed side.It folded over the thin lip that the boot locates in.The piston should have had a heat insulating disc in that large hole on the pad side.
The hose was cracked and getting ready to pop.
On the plus side:I believe that the bleed nipple is one of those Speed Bleeders.Should be cool for bleeding the brake if it works .Not a total waste of postage.The caliper will make a good test piece for my bushing locating guide.

[Big Dave]

Hope you get something out of it my friend , other then it leaked it worked ( well im still hear anyway)
Play away

Dave

[Dennman]

Hope you get something out of it my friend , other then it leaked it worked ( well im still hear anyway)
Play away

Dave

Play I will ! Been waiting on a tire so I can get the rear wheel on as well as my new chain.Then I can get a good bushed caliper together and bled.

[Dennman]

Tried posting the rebushing on the end of my first post but the damn page kept jumping so here's the process.

Got Dave's caliper and used it to get my Modus Operandi down.
Bolted his to my guide halves and drilled through my guide bushing holes.That caliper wouldn't clean up w/ the drill for the bushing OD.I did get a good clamping system out of the exercise.


Took the rear caliper off my scoot and bolted the halves to my guide caliper halves.
Clamped the assembly to my drill press.

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Drilled both holes.

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Then clamped the other assembly to the drill press.Placed a bolt in the hole to have a flat to clamp on.

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Drilled the holes.

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Ready for bushings.Installed with green loctite.

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Finished installation.Let the loctite set overnight and then back on the scoot.

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