So I finally got my brakes completely installed. Now they leak. The banjo bolts are torqued to 12 ft-lbs, the washers are installed properly. It looks like the bolt isn't going in straight, and thus not mating flush against the caliper. Any thoughts on this? I've run out of time and patience so I'm just going to tow it to a shop tomorrow and let them deal with it.

 

You cross threaded the banjo bolt. Are you using the proper size bolt?

You will have ti uyse a time sert to fix that caliper.

 

I was hoping it wasn't that. I threaded them both in by hand then torqued them.

 

Are these your old calipers? If not, someone damaged them before you.

 

No, I got them as a part of a kit. They look new to me.

 

Well its either cross threaded or the hole was drilled and tapped at an angle. Either way its needs to be drilled out and fixed with a heli-coil or similar.

 

please use a time sert, not a heli coil!!! Get yourself a m12x ??? (what is the proper thread 1.0 ?) time sert kit, it includes a guide bushing the correct drill and a tap. You can do it yourself. Drill the hole, tap the holewith the special tool thread in the time sert and thread it all the way to lock the cold rolled threads in place. Done, a perfect seal and no worries ever. Only issue is to keep chips from getting in the caliper. Might have to take the pistons out so a new seal kit is in order too. The calipers however are rediculously easy to rebuild.

 

Of course that can be a whole argument in itself. Heli coils are used in aviation all the time. They are made from 200ksi yield stainless steel which is far stronger than the bolt itself. Combined with the fact that the threads are larger than the bolt, it basically guarantees the bolt will fail before the insert. And of course the M10 banjo bolt torque spec is based on the crush washer not the bolt. An M10 bolt itself would be torqued to around 65 ft-lbs.

I'm sure in this case a time sert would work fine. But I really like that the heli coils have a Mil Spec defining specification. It is actually quite interesting reading if you are intersted in the subject.

MIL-I-8846D - should be able to find it online.

But back on topic. To the OP, no matter what you use, you need to make sure you re-drill the hole straight. This means doing it on a drill press or taking it to a machine shop. The seal on the crush washers depends on it.

John

 

Check that the metal block on the line is machined square. If not that is the issue, not the caliper.

RBob.

 

Sometimes just putting 2 washers on each side of the fitting, instead of 1, is enough.

 

It turns out I had one brake line upside down, and the other one was simply under torqued. 12 ft-lbs is apparently NOT enough to achieve crush.

 

I'm glad you found your problem.

 

Sure was a lot less of a problem than I thought LOL didn't even think of the brake line