Author Topic: Clogged brake lines. Suggestions?  (Read 5008 times)

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Offline juntjoo

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Clogged brake lines. Suggestions?
« on: May 26, 2016, 05:07:47 PM »
I don't have compressed air. Trying to get carburetor fluid Doree down there to clean and I've tracked it be clogging somewhere in the middle and at the master cylinder. Is there a special product for this or something?  And how would you get some fluid/cleaner into the cables at those tiny holes inside tha those end parts collar/sleeve looking parts? Excuse my ignorance. And and please enlighten. Thanks!
-Ben

82 Nighthawk 650..

1982 Honda Nighthawk...

I HAVE A 1982 HONDA NIGHTHAWK FFS! j/k. It's my only bike, my first and last.

Offline Steve_K

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Re: Clogged brake lines. Suggestions?
« Reply #1 on: May 26, 2016, 05:28:29 PM »
If the fluid lines are plugged and air does not clean it, you need new lines.  In fact, I suggest new ones cause the old ones are 40 years old.
Steve
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76 CB 550, 73CB750, 86 GSX-R750, 16 Slingshot
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Offline Patrick

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Re: Clogged brake lines. Suggestions?
« Reply #2 on: May 26, 2016, 05:35:05 PM »
The brakes on these old bikes are not award winners to begin with. Do you really want to trust your life to lines you forced crud out of? Are you sure you will get all of it so the lines don't plug up again when you are coming very quickly into the back end of another vehicle?

Seriously. Some parts are too important to just make them work.

Patrick
1970 CB750 K0
1982 VF750S Sabre
1987 VT1100 Shadow
1979 Yamaha XS11
1969 Yamaha DT1B
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Offline DaveBarbier

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Clogged brake lines. Suggestions?
« Reply #3 on: May 26, 2016, 05:37:02 PM »
First, carburetor cleaner eats rubber, might not be a great idea to shoot into the line because it may weaken it.

Second, if these are factory rubber lines it's best to replace them with stainless braided lines. Much better performance and being new they'll be far safer.

If the master cylinder is clogged, it can be removed, disassembled and rebuilt with new seals. But many people just buy new ones as well. Depends how far gone it is.

If the lines and MC are in bad shape, the caliper is probably not great either. Cleaning thoroughly and rebuilding with new seal and maybe new piston (if pitted) would be a good thing.

Post some pics of the lines and inside the MC. Would help to see what you're dealing with.

Offline DaveBarbier

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Re: Clogged brake lines. Suggestions?
« Reply #4 on: May 26, 2016, 05:46:34 PM »
http://www.rennsportautoparts.com/

They have nice lines and can do custom stuff if you need. It's best to call them up, they're really nice.

Offline mystic_1

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Re: Clogged brake lines. Suggestions?
« Reply #5 on: May 26, 2016, 05:47:39 PM »
Buy new lines.

mystic_1
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Offline eigenvector

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Re: Clogged brake lines. Suggestions?
« Reply #6 on: May 26, 2016, 05:47:57 PM »
I'm actually dealing with this very problem on my Nighthawk's clutch line.

Line is plugged for sure.

Do yourself a favor - unless you just can't find a replacement, get a new one.  I'm not too worried about my clutch line bursting, but I sure would hate to see your front brake line fail.
Rob
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2018 HD Softail Heritage
1979 CB750K Limited Edition
1977 CB550K
1984 CB700SC Nighthawk
1983 VF750S Sabre

Offline madmtnmotors

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Re: Clogged brake lines. Suggestions?
« Reply #7 on: May 26, 2016, 05:59:27 PM »
The damage is already done. Brake fluid is alcohol based. The rubber brake lines are designed to resist alcohol based fluids. Carb cleaner is petroleum based. Petroleum based fluids will turn alcohol resistant rubber to goo. You get three guesses as to how I came to learn this.

The first two don't count.


Replace the rubber brake lines, rebuild or replace the master cylinder, and rebuild or replace the brake caliper. Go ahead and replace the pads and scuff the rotor with a scotch brite pad while you're at it. Brakes are no place to "cut corners".
« Last Edit: May 26, 2016, 06:03:51 PM by madmtnmotors »
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Offline Matthewtanner

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Re: Clogged brake lines. Suggestions?
« Reply #8 on: May 26, 2016, 07:31:35 PM »
I just went through this with the goldwing, ~$50 for new front lines. I don't have a lot of disposable income, didn't feel like I NEEDED stainless lines, so just bought new ones. I originally planned to flush with alcohol...but all my line where plugged up so that I just ended up making a mess, drying my hands out, and rediscovering any open wounds on my hands. I'm all for using old parts, but the juice just isn't worth the squeeze for the brake lines.

Offline jonda500

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Re: Clogged brake lines. Suggestions?
« Reply #9 on: May 26, 2016, 07:46:09 PM »
You could have fixed this with fencing wire for the hoses(if they're not cracked), a selection of guitar strings for the master and metho to flush out the crap, but now the rubber parts will all need to be renewed due to exposure to the wrong type of liquid which as already mentioned will soften/dissolve them - don't ask me how I know this  ::)!
John
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Offline CycleRanger

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Re: Clogged brake lines. Suggestions?
« Reply #10 on: May 26, 2016, 07:57:57 PM »
The reason the brake line is clogged is because the inner liner has deteriorated and collapsed.
Replacement is the wisest course of action.
Do you have a copy of the Honda Shop Manual or Parts List for your bike? Get one here:
https://www.honda4fun.com/materiale/documentazione-tecnica
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Offline 70CB750

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Re: Clogged brake lines. Suggestions?
« Reply #11 on: May 27, 2016, 07:31:19 AM »
^^^ That^^^
Prokop
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Pure Gas - find ethanol free gas station near you

I love it when parts come together.

Dorothy - my CB750
CB750K3F - The Red
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Offline el pachuco

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Re: Clogged brake lines. Suggestions?
« Reply #12 on: May 27, 2016, 12:17:32 PM »
A lot of valid points are above..........However, if you still want to attempt to clear the clogged line, I had success doing so by using the hydraulic pressure from the master cylinder.  Disconnect the line just below the clog and hang it in a bucket or jug. Then work the brake lever until the clog is forced out.

That worked for me, after many unsuccessful attempts using cleaners and compressed air.

Offline DaveBarbier

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Re: Clogged brake lines. Suggestions?
« Reply #13 on: May 27, 2016, 01:14:26 PM »
A lot of valid points are above..........However, if you still want to attempt to clear the clogged line, I had success doing so by using the hydraulic pressure from the master cylinder.  Disconnect the line just below the clog and hang it in a bucket or jug. Then work the brake lever until the clog is forced out.

That worked for me, after many unsuccessful attempts using cleaners and compressed air.

After you clear the lines, consult a mortician.

Offline flybox1

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Re: Clogged brake lines. Suggestions?
« Reply #14 on: May 27, 2016, 01:32:46 PM »
A lot of valid points are above..........However, if you still want to attempt to clear the clogged line, I had success doing so by using the hydraulic pressure from the master cylinder.  Disconnect the line just below the clog and hang it in a bucket or jug. Then work the brake lever until the clog is forced out.

That worked for me, after many unsuccessful attempts using cleaners and compressed air.

After you clear the lines, consult a mortician.
:P
Its your choice, juntjoo, but there is one common theme in the responses above.
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

Past Bikes
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Offline el pachuco

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Re: Clogged brake lines. Suggestions?
« Reply #15 on: May 28, 2016, 06:02:00 PM »
For that matter, we should all just stay off of bikes, all together. They're dangerous and we will probably all get killed on them.
SMH!

Offline DaveBarbier

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Re: Clogged brake lines. Suggestions?
« Reply #16 on: May 28, 2016, 07:08:01 PM »
For that matter, we should all just stay off of bikes, all together. They're dangerous and we will probably all get killed on them.
SMH!

You go ahead and try forcing a fix on old failing brake lines. You won't have an H to S.

Offline flybox1

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Re: Clogged brake lines. Suggestions?
« Reply #17 on: May 28, 2016, 07:15:57 PM »
For that matter, we should all just stay off of bikes, all together. They're dangerous and we will probably all get killed on them.
SMH!
Wait....
We are advocating changing out a likely compromised part, and YOU tell saying its not necessary, and then coming down on all of US?
You really want that on your conscience?
smh

'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

Past Bikes
1974 550K0 (stock), 1973 CB350F (stock), 1983 Yamaha XS400K (POS)
77/78 cool 2 member #3
"Knowledge without mileage equals bullsh!t" - Henry Rollins

"This is my CB. There are many like it, but this one is mine…"

Offline el pachuco

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Re: Clogged brake lines. Suggestions?
« Reply #18 on: May 28, 2016, 10:58:31 PM »

Offline el pachuco

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Re: Clogged brake lines. Suggestions?
« Reply #19 on: May 28, 2016, 11:11:12 PM »
 I did have a clogged brake line on my '75 CB750. I did clear it, as described above. And I am running it.
But i never advised anyone to do what I did. I merely told the OP how I cleared MY line.
He can do with that information as he pleases.



Offline DaveBarbier

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Re: Clogged brake lines. Suggestions?
« Reply #20 on: May 29, 2016, 04:40:51 AM »
So back on the subject of good ideas...get new lines and go through the braking system rebuilding or replacing questionable parts.

Offline mystic_1

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Re: Clogged brake lines. Suggestions?
« Reply #21 on: May 29, 2016, 04:55:54 AM »
the cables at those tiny holes inside tha those end parts collar/sleeve looking parts

Those fittings are called "banjo fittings" by the by.

Also, the little washers that were on either side of each banjo fitting when you removed them are crush washers, and should be replaced each time you use them, they're more or less little gaskets.

mystic_1
"A ship in harbor is safe, but that is not what ships are built for."
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Offline juntjoo

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Re: Clogged brake lines. Suggestions?
« Reply #22 on: June 04, 2016, 08:25:20 AM »
Crush? Like with the split and little bend? Not mine. Just flat and unbroken.
-Ben

82 Nighthawk 650..

1982 Honda Nighthawk...

I HAVE A 1982 HONDA NIGHTHAWK FFS! j/k. It's my only bike, my first and last.

Offline juntjoo

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Re: Clogged brake lines. Suggestions?
« Reply #23 on: June 04, 2016, 08:26:23 AM »
Thanks all for the replies. I've got the message here.
-Ben

82 Nighthawk 650..

1982 Honda Nighthawk...

I HAVE A 1982 HONDA NIGHTHAWK FFS! j/k. It's my only bike, my first and last.

Offline juntjoo

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Re: Clogged brake lines. Suggestions?
« Reply #24 on: June 04, 2016, 08:27:47 AM »
http://www.rennsportautoparts.com/

They have nice lines and can do custom stuff if you need. It's best to call them up, they're really nice.

Thanks. Will check it out
-Ben

82 Nighthawk 650..

1982 Honda Nighthawk...

I HAVE A 1982 HONDA NIGHTHAWK FFS! j/k. It's my only bike, my first and last.