Brake options for early front ends

[TAlber8]

On 74 front end. Have chased never ending front brake issues. Replaced all front brake components. Multiple MCs, SS line, caliper from Mikes.... only the union line from caliper is original.

I think this caliper is junk is my current issue.

Any interesting upgrade solutions that let me keep these forks, and ideally the fender too?

I’ve seen the older threads with that one brembo caliper... was wondering What else people have tried.


Also, anyone know the fitting for use on those early calipers? I would maybe try a one piece line first.

 

[Team Junk]

The TXA caliper is a nice 2 piston caliper. It is cast iron and a little heavy. As far as braking power it is outstanding for it's time. When setup correctly it will lock the front wheel with a two finger pull. Do you have the original round top M/C ? For some reason this setup seems to have issues bleeding air out of the system.
I think that might be your issue.

 

[TAlber8]

I do not have the original but replaced lines and caliper after discovering one piston in original was seized.

I tried a few diff MCs.... mityvac, reverse bleeding with syringe. Literally multiple bottles of fluid. Never had this issue before on systems.

that solid line through fender makes it difficult to try and placing caliper up high to bleed;

that’s why I was starting to think maybe it was a junky caliper.

 

[XsJosh]

I do not have the original but replaced lines and caliper after discovering one piston in original was seized.

I tried a few diff MCs.... mityvac, reverse bleeding with syringe. Literally multiple bottles of fluid. Never had this issue before on systems.

that solid line through fender makes it difficult to try and placing caliper up high to bleed;

that’s why I was starting to think maybe it was a junky caliper.

 

[XsJosh]

I found with mine you need to clean out all the tiny passages in the MC with a paper clip or such and I've had luck putting a zip tie holding it applied over night or for a day or two. I have an original 75 MC available if you're interested as well as calipers.

 

[arcticXS]

My 74 RD350A has the exact same caliper, and it was very good. I now have a reproduction of that same caliper, in aluminum alloy, purchased from Economy Cycle on my RD. A lot lighter, and also very good. The largest improvement you can do, is a 12 or 13 mm bore master cylinder and a one piece teflon brake line. This requires a master cylinder with integrated brake light switch, I am using a 13 mm Brembo with a rectangular reservoir ("coffin type")
It is definitely doable to omit the hard line, and use a banjo on the caliper. At the bottom of the threaded hole is a cone, designed for sealing with a straight pipe or hose. This cone is actually removable, or you can get a hose with the same fitting as the hard line.
That may not necessarily be the best option though, I would try to find a braided teflon hose that goes directly from the (Brembo) master cylinder to tne hard line.