caliper calamity

[jimbonaut]

Servicing the brake system, everything was going well until it wasn't -



- bleeder valve sheared right off. The valve in both the front right and left calipers were really rusted and seized - some PB Blaster got one of them but the fight with the valve in the left caliper did not end well. I've tried drilling it out but not having much luck actually drilling into the meat of it and I can't think how else to get at it. Any suggestions?

And if it comes to it, does anyone have a left caliper I can buy? I have a '76. Will a caliper from a '77 fit?

Also, considering upgrading the brakes lines to stainless HEL lines.

[robin1731]

Do you have a welder or know someone who does?

[dontwantapickle]

Yup.
It is what it is...
buy another caliper.

[jimbonaut]

Do you have a welder or know someone who does?

I do…what do you recommend?

[pidjones]

They make a bleeder screw repair kit. Drill and tap a larger hole and screw it in. Smaller bleed valve in the middle. I've used several with good success. https://www.amazon.com/dp/B0024HMRIU

[Whiskerfish]

Do you have a welder or know someone who does?

I do…what do you recommend?

Welding that small would be a serious challenge. Normally you hold a nut over the top of the sheared "bolt" and weld the inside of the nut to the center of the "Bolt" then use the nut to unscrew it. Have done it many times and it works well but doing it on something that small........may be possible, just way beyond my skill levels. Steel bleeder into Aluminum is always a challenge.

[robin1731]

What he said. ^^^^^^^^^^^^

Mig welder. Or you can use copper tubing over the broken part as a shield to build up the steel.

[Track T 2411]

To answer your other question, '75-77 calipers are all the same.

[leonardhcross]

Hi James. I'm sure I have an extra caliper. In fact, I just scavenged a couple of small pieces from one caliper so it would be just right for you. Don't want much. PM me.

[jimbonaut]

That's very decent of you Len, thank you for the offer. Digging in a bit deeper into these calipers and my problems don't end with a sheared bleeder valve. Disassembled the right caliper and couldn't shift the piston for love or money. Compressed air didn't budge it (unsurprising given the amount of rust around the opening) and the only way I could remove it was with channel locks. Here's the piston -



and here's the inside of the pot -



...ugly as a blind cobbler's thumb. So I'm going to need both left and right caliper - they don't need to be pristine (I'll rebuild them with a Brake Crafters kit and new pistons) but they will need to be serviceable. Thanks in advance

[jimbonaut]

They make a bleeder screw repair kit. Drill and tap a larger hole and screw it in. Smaller bleed valve in the middle. I've used several with good success. https://www.amazon.com/dp/B0024HMRIU

Thanks for letting me know pid, I had no idea. I tried drilling the bleeder valve out but had no luck whatsoever. It seems like there's some kind of core in the thing that is undrillable, I must have tried 15 different drill bits but nothing did the trick. Like the thing's made out tungsten or something? Not what I was expecting at all.

[pidjones]

They make a bleeder screw repair kit. Drill and tap a larger hole and screw it in. Smaller bleed valve in the middle. I've used several with good success. https://www.amazon.com/dp/B0024HMRIU

Thanks for letting me know pid, I had no idea. I tried drilling the bleeder valve out but had no luck whatsoever. It seems like there's some kind of core in the thing that is undrillable, I must have tried 15 different drill bits but nothing did the trick. Like the thing's made out tungsten or something? Not what I was expecting at all.

Probably has an Easy-out snapped off in it.

[jimbonaut]

That's what I thought, but I don't know how there'd come to be an easy out inside the bleeder?

[leonardhcross]

That's very decent of you Len, thank you for the offer. Digging in a bit deeper into these calipers and my problems don't end with a sheared bleeder valve. Disassembled the right caliper and couldn't shift the piston for love or money. Compressed air didn't budge it (unsurprising given the amount of rust around the opening) and the only way I could remove it was with channel locks. Here's the piston -



and here's the inside of the pot -



...ugly as a blind cobbler's thumb. So I'm going to need both left and right caliper - they don't need to be pristine (I'll rebuild them with a Brake Crafters kit and new pistons) but they will need to be serviceable. Thanks in advance

Man, that is one ugly piston. I have never seen one that bad. I think you will be pleased with the ones that are on their way. Also...Following posts in this forum, I have used both a grease gun and a spare master cylinder mounted on a spare set of handlebars to "pump out a stuck piston. I have seldom had success using air pressure. Here is a pic of my jig. As I recall, one needs to split he caliper, insert a piece of rubber to block the return line, then pump the piston out.

Master Cylinder Pump.jpeg

[jimbonaut]

Yeah, I like that set-up Len - I have a new master cylinder lying around somewhere (bought for a different project) so I'll give your suggestion a try. I've rebuilt a few calipers but I've never come across one this bad either...pretty much sums up a lot of things I've had to deal with on this bike. It's called Swamp Thing for a reason.

Thanks a lot for getting those calipers shipped so quickly - I really appreciate that Len. I'll let you know when they show up