Topic: brake line threads

[snoop]

Just got a nice new brakeline in today.  This is the part that goes in to the caliper.  Do I have to prep the threads with anything before I put it in?  Also the old line is a #$%* to remove so I am thinking the old one might have locktite on it.  The old one is rusted to bits.  I guess I am gonna take an impact driver to it.

[OldSchool_IsCool]

Snoop,

Are you talking about the short steel pipe that goes from the caliper to the fender hook on your front brake?  Is that the piece you are replacing/having trouble getting out?

I don't believe it will require any thread dressing to seal.  When I replaced my front brake lines, I went with braided stainless all the way from the master to the caliper and eliminated the steel pipe.  Others may be able to give you more practical experiences with sealing up a new steel pipe.

[snoop]

Yes, it is the steel pipe.

[Al_Aaraaf]

Anyone know the thread pitch on the steel pipe fitting going into the caliper on a CB550F? It's completely different than the banjo bolts and the guy at HEL is confused with what to go with on my new lines.

[Bodi]

I'm pretty sure it is 10mm x 1.25mm, a shortened banjo bolt will work or you can drill (8.75mm or 11/32) out the steel flare seat and go somewhat deeper - you'll run into the bleeder hole and ruin the caliper if you go super deep - and tap it with a plug or bottom tap, and then use a standard single banjo bolt. I don't know what the flare fitting is, maybe HEL can figure that out from the thread size if you don't want a banjo or you could send them the hard line to look at. The seat where the crush washer sits on the caliper is smaller than the washers Honda uses but the coppery looking ones I get at auto parts stores work as they are a lot thicker and a bit smaller diameter than Honda OEM - Honda ones generally don't work at the caliper because they are slightly larger than the flat face counterbore around the line fitting hole. I use banjos to avoid having to find a flare fitting that fits onto the caliper, it looks pretty good with a 30 degree banjo in my opinion.

[Al_Aaraaf]

Thanks for the info. As of last night, he emailed me a sample and it looks like he may have just guessed the correct flair fitting (always wondered what those damned things were called). He's going to run straight down with line and fitting at the caliper.

Tricky stuff, measuring all that out. I went with a 33" line from banjo to flair. This should provide plenty of room for travel, but anyone with experience going with a striaght line can give me some piece of mind that I made the right call, it'd be appreciated. Going with Nissin Master on my drag bars and eliminating the switch block between the forks. I'm real stoked to get some better braking feel out of this thing.

[Blaize]

You never need to seal the threads on brake lines. The sealing surface is the little dished part at the end of the pipe. Not the threads themselves.

[bwaller]

Bodi explained well the route I opted for, drilling out the steel seats and running a bottoming tap for more threads, that way using banjo's at both ends of the lines. I also machined a larger flat surface for crush washers on the top of the calipers.

I'm using 400F bars (slight rise) on this 550 and the longest brake line, center banjo to center banjo, is 29.5" so you'll be plenty long enough with 33"