Replace Brakes or Rebuild

[Longbow62]

I'm wondering if it's better to just buy replacement calipers and master cylinders vs. rebuild on a bike that is 46 years old, and has been sitting 30+ years. Also the stock calipers weigh a ton. Are the replacements lighter weight? Everything is there on the bike I bought but even though it looks to have been kept in the dry all that time the parts don't look great once you take them apart. 

[m in sc]

take apart and inspect. they are easy to rebuild.. you'd be amazed how well they hold up. new seals and pistons prob fine.

[Longbow62]

Thanks, I guess I'll take them apart and take a look. I'm thinking pretty hard about going and buying an ultrasonic cleaner anyway. 

[RustyRD]

One vote for ultrasonic cleaner, I have two and wish I had bought them earlier.

[Longbow62]

The ultrasonic cleaner got one of my carb slides unstuck after about 2 hours with diluted super heated simple green. Caliper halves stayed in 2.5 hours. The pucks are still stuck. I've tapped with a hammer. They are soaking in WD-40 now. Any tips to get stuck pucks out? 

[RattlecanResto]

The ultrasonic cleaner got one of my carb slides unstuck after about 2 hours with diluted super heated simple green. Caliper halves stayed in 2.5 hours. The pucks are still stuck. I've tapped with a hammer. They are soaking in WD-40 now. Any tips to get stuck pucks out? 

I pump them out with grease. You can also use air pressure but need to be careful. You likely won't get them out any other way. Search YouTube prob some videos on there.

[m in sc]

i use air. 90-100 psi shoot the puck into a 5 gallon bucket filled with rags. a bit of heat doesnt hurt either.

[kpke]

The ultrasonic cleaner got one of my carb slides unstuck after about 2 hours with diluted super heated simple green. Caliper halves stayed in 2.5 hours. The pucks are still stuck. I've tapped with a hammer. They are soaking in WD-40 now. Any tips to get stuck pucks out? 

Try this

[SoCal250]

+1 for Ken's technique.
I had some really stuck pistons on my TZR that wouldn't come out after ultrasonic cleaning and trying to push the pistons out with compressed air. I used Ken's method above, but I also heated the calipers in my gas BBQ on low then melted ice cubes inside the piston cup before trying to extract. Worked great

[Longbow62]

My calipers and internals are like in horrible shape. Really rusty and corroded compared to the ones in the video, which by the way look new compared to mine. I will try several things, but I doubt the video method will work. Thanks for the suggestions.   

[pdxjim]

I gave up on my LC calipers and replaced them with ones off an R1/R6

If you're not trying to keep it all original, this is a win win.

[Dvsrd]

My calipers and internals are like in horrible shape. Really rusty and corroded compared to the ones in the video, which by the way look new compared to mine. I will try several things, but I doubt the video method will work. Thanks for the suggestions.   

The alloy reproduction calipers Economy Cycle sold me work great! They look just like the stock RD350/400 calipers (not Daytona!), and are significantly lighter than the original iron/ steel calipers.
Combined with a smaller bore master cylinder (12-13 mm) and a modern teflon lined hose will give you all the brake you need.

[axldk6]

I haven't even gotten to that part of my build, ( bought bike in 08/24).still sorting out engine. but some time in it life the M/C was replaced ( not original) and the caliper looks like junk and the brake line goes straight from M/C to caliper. I am going to do a all new swap , but also would like to upgrade to better component's?

[m in sc]

I mean, the stock caliper 'if' its in good shape works great. if not worth saving, the stock replacements with a slightly smaller master as stated is a great route, OR, change over to an r6/r1 type caliper with an adapter and an fz rotor. more brake than you'll ever need. (theres info int he tech section on this)

[teazer]

My calipers and internals are like in horrible shape. Really rusty and corroded compared to the ones in the video, which by the way look new compared to mine. I will try several things, but I doubt the video method will work. Thanks for the suggestions.   

The alloy reproduction calipers Economy Cycle sold me work great! They look just like the stock RD350/400 calipers (not Daytona!), and are significantly lighter than the original iron/ steel calipers.
Combined with a smaller bore master cylinder (12-13 mm) and a modern teflon lined hose will give you all the brake you need.

Those calipers are so much lighter and the pistons can be replaced with suitable alloy pistons too.  But there is a slight difference in diameter, so aftermarket pistons may have to be machined to fit. I use that set up on an RD400 drag bike.  Looks stock but saves a bunch of weight.