Clogged brake lines

[xs1100newb]

Hello,

Thanks to a lot of help by people on the forum I finally properly bled the front brake system and it works like a charm.


I have moved on to the rear brake system. I disassembled and cleaned the rear master cylinder and caliper.

Before connecting the rear mc to the brake line I filled it with brake fluid and and pumped the piston several times. Fluid came out of the exit port.

I then connected the rear mc to the brake line and screwed it into the frame and connected the rod which connects to the rear brake lever. I attempted the regular bleeding process using a mityvac. I cannot get fluid to leave the rear mc and enter the brake lines and caliper. I pushed the brake lever a bunch of times to see if anything would happen and nothing did.


I absolutely made sure the splooge hole was clean and besides fluid came out of the exit port when it was not connected to the brake line.

Any advice?

Adam

[natemoen]

Have you cleaned the rear caliper? Sometimes the bleeder screws get rusty and clogged inside.

[xs1100newb]

The bleeding screw is not clogged. I removed it completely to wrap it in teflon tape before I began the bleeding process.

Adam

[DGXSER]

Did you make sure the teflon tape did not get moved and cover the bleed screw hole?

Also, the rear brake is a royal PITA to bleed from all of the work I have done on them. You just have to really get a good seal on the mity vac and pump and bleed until you think your sucking your brain out of your head. At least that is how it always goes for me.

[xs1100newb]

I have heard that as well. But for now, I cannot even get fluid to flow through the brake lines.

Is it possible they are clogged? What can I do?

[DGXSER]

Pull the brake line off, and check that you can blow air through it, or spray brake cleaner into it and swash around and dump it out. That will tell you if it is clean and clear.

If it is, then I'd say you just need to keep at it.

[xs1100newb]

I notice for the rear there are two rubber brake lines connected by a metal rod. It seems that the metal rod is threaded into the rubber brake lines. Can I unscrew this?

Adam

[natemoen]

In my bike when I first got it I found that the metal line had rusted closed. I did clean the clog out but the brake never really worked well after that. I would say get rid of it if it is rusted shut. I have ss lines now!

[natemoen]

And yes that metal line does unsure from the rubber lines.

[Incubus]

If the bike has been sitting a long time brake fluid can indeed congeal and clog the lines. I have found it before. If this were my bike I would replace the line. I have never successfully unclogged a clogged brake line. Of course, I haven't tried very hard. Is it worth a few dollars to you to have back brakes when you need them? Most bike shops sell generic stainless steel brake lines and the rear brake uses a fairly common length.

Patrick

[xs1100newb]

Any suggestion where I can find a generic brake line for the rear. It can be rubber or stainless steel.

I would prefer the cheapest thing possible.

Adam

[Incubus]

Call around to bike shops in your area. I replaced the brake lines on my old CB750 with lines I picked up from a Harley shops. The rear on the XS121 is, IIRC, 19 inches. That would cost about $20 (in SS) at a bike shop I frequent hereabouts.

Patrick

[xs1100newb]

The fittings are all the same?

Adam

[Incubus]

You need 10mm banjo bolts. That's the same size Harleys use. DON'T go to a Harley dealership or they will charge you $50 or $60 or more for a brake line. DO GO to a local shop frequented by Old Time bikers, Harley or otherwise.

You also find relatively inexpensive brake lines online, at Ebay or Dennis Kirk or any number of other sites. I recommend local because if no one buys locally pretty soon you will have to buy online as ony the dealerships and online stores will survive.

Keep you neighbors employed. Buy local.

Patrick