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obstructed brake line advice

Posted: Mon Sep 12, 2022 7:12 am
by Trip
what is the best way to clear a brake line that is obstructed ? I have tried solvent, air and everything else I can think of.

I thought someone on here might have a method I have not tried.

Brake line is oem and in good outside condition and I would prefer to save and re use if possible. It is also about 4 feet long with a couple of sharp bends.

Thanks in advance!

trip

Posted: Mon Sep 12, 2022 8:46 am
by wesk
I moved your question from our projects board to this here Technical Knowledge board.

Get a roll of .040 steel safety wire. Cut off a length = to the tube and start poking and scratching. Or get a hand hydraulic pump that you can connect (with threaded fittings) to the line and apply at least 75 to 100 Lbs of hydraulic pressure on the tube.

Posted: Mon Sep 12, 2022 11:42 am
by rgmutchler
Trip
I might be wrong but could your brake line be like the USS Texas, rusting from the inside out, could that be why it is obstructed.
Just a thought.
Ralph

Posted: Mon Sep 12, 2022 11:51 am
by Mike_B
My vote would be to replace the line. If it's really OEM like you say, than it's already old. You may or may not know but brake lines fail from the inside out, they might look good on the outside but are a rusty mess on the inside. Even if you break the blockage loose, now you have to worry about that junk circulating around in the system reeking havoc on your wheel cylinder walls and cups.

Brake lines are cheap and easy to make so why risk it?

Mike B :)

Posted: Mon Sep 12, 2022 7:28 pm
by wesk
Trip,

I should have been more detailed on my reply. Make sure you have the line disconnected from the system before you try to scratch it clean or hydraulic pressure flush it.

I would wait and see what comes out of the tube before I scrap it!

Brake lines that rust out from the inside have water in them and have not had any DOT 3 & DOT 4 in them for several year. This is why the industry standard for DOT3 is change every 2 years. The overrated silicon DOT 5 is a bigger pain then it is worth. Unlike DOT 3 & 4 which absorb moisture the silicon based DOT 5 isolates moisture and the moistures settles in the low spots and starts the same rusting process. Sometimes we screw up and mix the DOT 5 with DOT 3 or 4 and then all kinds of congealing messes show up. This is why one should always confirm by taste or smell which brake fluid he has in his jeep before you tilt the can.