Replaced brake lines now I can't bleed the system

chesthing

Joined
Jun 6, 2008
Messages
246
Location
Colorado
Bike
R1200RT
Non-ABS ST1100, I'm trying to replace with steel braided lines and after an hour of trying I can't get any brake pressure.
I'm doing it without vacuum, turn the bleed screw out a bit, pull brake handle in, close screw and release handle. I little fluid comes out on both sides each time, but I can't get any pressure. All banjo bolts are torqued to spec.
I've never tried this, in the past I've only replaced fluid - please help before I chuck a wrench through a window!
 
IIRC, you'll need to add fluid and pump with the nipples closed until you get some pressure in the system, then you'll be able to start the normal bleed process.

Another option is to use something like a turkey baster and a piece of clear hose to force fluid INTO the bleed nipples, up to the master cylinder. Can get messy, though.
 
chesthing said:
I little fluid comes out on both sides each time, but I can't get any pressure.
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I presume you are referring to the front calipers since you reference 'both sides'. I dont know that you cant do both at the same time but if that is what you are attempting, then I would suggest you only bleed one side at a time. I replaced my brake lines a few months ago and I only bled one side at a time and everything worked out OK.

You may want to think about a Mity Vac or someting similar if you continue to have a problem.
 
I called Galfer tech support and was instructed to pump the lever several times, then crack open the banjo bolt at the master cylinder to let fluid and (hopefully) air out. After about 5 tries it worked like a charm, thanks for the replies.
 
TTT...I realize this thread is a bit over two years old, but the info is still relevant. I'd rather add to this than start another thread I guess.
I'm having some bleed trouble after rebuilding a caliper. I did a search here and found this, and a number of other threads offering some ideas.
My main question is, Why are these systems SO hard to purge? I've been trying to do it conventionally, like on a car...pump, pump, hold, crack bleeder/tighten bleeder, and repeat. I've pumped/cracked the bleeder ??100 times...still no pressure whatsoever. I did crack the banjo bolt at the caliper, but not at the master as suggested here. I will try that next. I do not own a mighty vac. I do have a long length of tight fitting hose attached to the bleeder screw. I've tried sucking on it while cracking the bleeder and it did not do anything but make me dizzy(er:eek:: )

chesthing said:
....... - please help before I chuck a wrench through a window!
Click to expand...
<<<< what he said!!
 
From what I have read and how the OP fixed his bleeding problem you have an airlock at the master cylinder.
The Galfer people recommended pumping up the pressure and cracking the banjo bolt to get fluid into the master cylinder.
From your last post it looks like you tried the Galfer suggested technique, any change? No, I thought not as you're back.

You might try a pumping brake fluid backwards through the system with a turkey baster.

As to your question about why is it so hard to purge these systems... I didn't answer that one because I have seen this issue with brake systems on cars too.
 
The master cylinder location allows a "high spot" where the banjo connection is located under most circumstances. Basically, you can bleed it forever, but the bubble of air will remain in that location. Take it from those who have been down that road for many hours and bleed THAT particular spot, then your headache and muscle aches should lessen.
 
Just for some clarification since I will be doing the same thing soon, you want to loosen the banjo bolt at the master cylinder, and squeeze the lever to force some fluid out at that point. Then re-tighten, and proceed with the normal bleed routine?

Also, with new lines, would it be beneficial to loosen each of the banjo bolts at the calipers, one at a time, and perform the same sequence to get fluid into the lines prior to bleeding the calipers using the bleeder screw?
 
Thanks Mark and Dooda. I've not built one ounce of pressure. Pumped the damn lever so many times I had to switch hands......(refrain from the wise cracks :eek:::D:eek::!! ) Upper banjo bleed next time I'm over where the bike is.

AZ711, I can't help you as I can't seem to figure it out myself. I've bled more cars than most and NEVER had an issue...dry, wet, new calipers/lines/ bla bla bla..these bike brakes suck for some reason.
 
I have worked on cars trucks and bikes for years I have found that the easiest way to bleed any system is Open the bleeder apply the brake close the bleeder release the brake, repeat, once fluid starts coming out then you can pump up the brakes and bleed normally. also always start with the bleeder farthest away from the master cylinder. Good luck
 
Doodaa said:
The master cylinder location allows a "high spot" where the banjo connection is located under most circumstances. Basically, you can bleed it forever, but the bubble of air will remain in that location. Take it from those who have been down that road for many hours and bleed THAT particular spot, then your headache and muscle aches should lessen.
Click to expand...

Thanks Mark and Dooda......success!!!!!!!!!!!!!!!!!!!!!!!!! I removed the top fitting at the master and held my finger over the hole and pumped a few times...pressure.....finally pressure! Reattached the line and, while the bleeding was slow to buid pressure again, it was steady progress. Now ZERO air, a firm lever, and proper caliper release (my original prob was a hung caliper)

Thank you.......:bow1:
 
SMMc-ST said:
Thanks Mark and Dooda......success!!!!!!!!!!!!!!!!!!!!!!!!! I removed the top fitting at the master and held my finger over the hole and pumped a few times...pressure.....finally pressure! Reattached the line and, while the bleeding was slow to buid pressure again, it was steady progress. Now ZERO air, a firm lever, and proper caliper release (my original prob was a hung caliper)

Thank you.......:bow1:
Click to expand...


So, taking it one step further: if you are replacing the banjo bolt crush washers when installing new brake lines, and you don't want to lose the sealing advantages of the washers by tightening and then untightening the bolts, perhaps the standard bleeding procedure is to not torque the banjo connections at the master cylinders until after bleeding at the MC.
 
STraymond said:
So, taking it one step further: if you are replacing the banjo bolt crush washers when installing new brake lines, and you don't want to lose the sealing advantages of the washers by tightening and then untightening the bolts, perhaps the standard bleeding procedure is to not torque the banjo connections at the master cylinders until after bleeding at the MC.
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Disagree. The washers are copper, they will withstand a lot of loosen/tighten cycles. In fact, it's my preference to re-use the old washers if they are not damaged. Never had one leak, which is more than I can say for new ones. But, to each their own. I bleed with an air powered Vacula brand bleeder. Bought it years ago, and it makes the bleed job a snap. In fact, I'm looking at building a bleed harness for the 13 that connects to each bleeder screw. this way I can purge and bleed the whole brake system in one shot.
 
Ozzie said:
Disagree. The washers are copper, they will withstand a lot of loosen/tighten cycles. In fact, it's my preference to re-use the old washers if they are not damaged. Never had one leak, which is more than I can say for new ones. But, to each their own. I bleed with an air powered Vacula brand bleeder. Bought it years ago, and it makes the bleed job a snap. In fact, I'm looking at building a bleed harness for the 13 that connects to each bleeder screw. this way I can purge and bleed the whole brake system in one shot.
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Oh, oh - and I just bought new washers for all the banjo bolts. I am going to retrieve the old ones that I removed - in case the new ones leak. Your multi bleeder device sounds cool.

Ray
 
STraymond said:
Oh, oh - and I just bought new washers for all the banjo bolts. I am going to retrieve the old ones that I removed - in case the new ones leak. Your multi bleeder device sounds cool.

Ray
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Many years ago I did not have a replacement copper crush washer. I heated the washer red hot, quenched it in cold water and cleaned it up on very fine wet-or-dry paper. Twas annealed copper and it worked perfectly. In fact, my Triumph manual (1969) suggests doing this with the head gasket, too. A word of caution - i once got carried away and melted the crush washer. They don't seal too well after this treatment.....
 
Minor point - there's no need to "quench" copper (or aluminum) after heating/annealing. You're not tempering steel here. Air cooling is fine for copper washers; dipping them in a bath of water just cools them so they can be handled a minute or so sooner.

Keep in mind that each time you anneal a copper washer after it's been used, it will be thinner, having less metal to "crush."

John
 
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I just replaced the front brake lines with Galfer braided SS last weekend as part of my winter maintenance projects. I had to rebuild the front calipers because the seals were swelled up from corrosion. This caused the pistons to lockup and drag the brakes. Same thing happened to the rear brakes last year. Bleeding after a complete drain/refill is slow going. Once I got any fluid coming out and the lower bleed ports I had to work the top end and the master cylinder and get the air out from there before I made any progress at the calipers.

I used DOT 5 with the new lines and seals. I feel it was the hygroscopic nature of DOT 4 that trapped moisture under the seals. Over time they swelled up and pressed the seals into the pistons. I carefully scraped out a lot of yellowish crud from the seal grooves. That was probably dried up contaminated DOT 4 residue. With DOT 5, that won’t happen again
 
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