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Main Area => General GS500 Discussion => Topic started by: Watevaman on October 22, 2012, 11:42:58 AM

Title: Clarifying procedure for changing front brake line
Post by: Watevaman on October 22, 2012, 11:42:58 AM
 So I bought a stainless steel front line from HEL and am going to probably install it later tonight or tomorrow afternoon. However, I just want to make sure I'm clear on everything. Is this the correct procedure?

-Bleed brake as is, getting all the fluid out and essentially waiting until air is coming through the bleeder valve
-Replace line same way as it is
-Pour fluid into resovoir and pump until fluid (with no air bubbles) comes out of the bleeder valve


I've never done brake bleeding before and I really don't want to screw up what is essentially the only thing between me and a wall.
Title: Re: Clarifying procedure for changing front brake line
Post by: weedahoe on October 22, 2012, 02:21:41 PM
No since in bleeding before changing the line IMO.


Change the line
pour in new DOT 4 fluid
pump the lever
crack the bleeder valve with clear hose attached
when the pressure is released, close the valve, pump, crack, drain, close valve, pump, crack open, drain

just add fluid as needed and until all the bubbles are out and clear, clean fluid comes out also.
Title: Re: Clarifying procedure for changing front brake line
Post by: RossLH on October 22, 2012, 02:31:50 PM
Quote from: weedahoe on October 22, 2012, 02:21:41 PM
No since in bleeding before changing the line IMO.


Change the line
pour in new DOT 4 fluid
pump the lever
crack the bleeder valve with clear hose attached
when the pressure is released, close the valve, pump, crack, drain, close valve, pump, crack open, drain

just add fluid as needed and until all the bubbles are out and clear, clean fluid comes out also.

That does work, but I've found its a lot easier and faster to just pump fluid in from the bleeder. This also guarantees that no air is left in the system.
Title: Re: Clarifying procedure for changing front brake line
Post by: 802 305 on October 22, 2012, 02:52:19 PM
I swapped mine recently for HEL as lines... I bought the righ tyear kit and the bolts they included fit the master cylinder, but not the brake... I cleaned out the old one and used it down there. Excellent brake feel. I just mopped up the fluid in the cylinder and disconnected the line from the caliper... let it all come out avoiding any painted surfaces and your disc, hook everything up, and bleed it. Takes a minute to run out all the air but pretty simple operation.
Title: Re: Clarifying procedure for changing front brake line
Post by: Watevaman on October 24, 2012, 11:13:40 AM
 Alright, I'm kind of confused now. I replaced the line, I'm bleeding the brakes. No air in the line as far as I can tell, but my brake lever is soft as hell. There is zero resistance whatsoever. Did I do something wrong? Is there still an air bubble in the line that I need to force out? I've put almost half the bottle of fluid into the front resovoir alone.
Title: Re: Clarifying procedure for changing front brake line
Post by: weedahoe on October 24, 2012, 11:15:36 AM
Still got air somewhere
Title: Re: Clarifying procedure for changing front brake line
Post by: 802 305 on October 24, 2012, 11:23:44 AM
Make sure you have the washers on there... did the bolts fit correctly? When I used my old bolt for the caliper, I had an air leak because I used one of the old washers (didn't notice it, thought it was part of the banjo bolt) and two new washers. Good luck
Title: Re: Clarifying procedure for changing front brake line
Post by: dry_humor on October 24, 2012, 11:50:03 AM
i know it might sound silly, but some people forget to put the reservior cap back on and tighten it down before any pressure will be felt at the lever.....
Title: Re: Clarifying procedure for changing front brake line
Post by: bryan88 on October 24, 2012, 12:04:37 PM
Quote from: dry_humor on October 24, 2012, 11:50:03 AM
i know it might sound silly, but some people forget to put the reservior cap back on and tighten it down before any pressure will be felt at the lever.....
Please elaborate, never heard that one before.
Title: Re: Clarifying procedure for changing front brake line
Post by: Funderb on October 24, 2012, 12:06:03 PM
Quotei know it might sound silly, but some people forget to put the reservior cap back on and tighten it down before any pressure will be felt at the lever.....

not sure thats true? as long as the res isn't dry you should get pressure.
Title: Re: Clarifying procedure for changing front brake line
Post by: Watevaman on October 24, 2012, 12:36:02 PM
 Alright, guess I did have air somewhere. Kept bleeding and it was fine. Thanks for the help guys!
Title: Re: Clarifying procedure for changing front brake line
Post by: kyled25 on October 24, 2012, 01:05:52 PM
Quote from: Funderb on October 24, 2012, 12:06:03 PM
Quotei know it might sound silly, but some people forget to put the reservior cap back on and tighten it down before any pressure will be felt at the lever.....

not sure thats true? as long as the res isn't dry you should get pressure.

It's not true... the reservoir is just that, a reservoir. The cap just keeps extra fluid from spilling out/contaminate from getting in the reservoir. The master cylinder is what generates pressure in the line down to the caliper for braking.
Title: Re: Clarifying procedure for changing front brake line
Post by: ThatOtherGuy on October 24, 2012, 02:09:11 PM
just a general tip, if you think you have air trapped in a line, sometimes a gentle tapping with a hammer handle (ie the wooden end, not the business end) can agitate the bubble out of the nook its in.  let the bubble rise out or bleed it out whichever you like.
Title: Re: Clarifying procedure for changing front brake line
Post by: dry_humor on October 24, 2012, 07:33:46 PM
Quote from: kyled25 on October 24, 2012, 01:05:52 PM
Quote from: Funderb on October 24, 2012, 12:06:03 PM
Quotei know it might sound silly, but some people forget to put the reservior cap back on and tighten it down before any pressure will be felt at the lever.....

not sure thats true? as long as the res isn't dry you should get pressure.

It's not true... the reservoir is just that, a reservoir. The cap just keeps extra fluid from spilling out/contaminate from getting in the reservoir. The master cylinder is what generates pressure in the line down to the caliper for braking.

meh. when i do brake work and have the cap off, i can pump the lever all day long and get no action at the caliper. even with proper bleeding. once i have my reservoir cap back on, then things will work properly. brakes are closed systems, so i would imagine leaving the cap off would ultimately leave this closed system...open. open system, no worky.
Title: Re: Clarifying procedure for changing front brake line
Post by: ThatOtherGuy on October 24, 2012, 07:54:12 PM
Quote from: dry_humor on October 24, 2012, 07:33:46 PM
Quote from: kyled25 on October 24, 2012, 01:05:52 PM
Quote from: Funderb on October 24, 2012, 12:06:03 PM
Quotei know it might sound silly, but some people forget to put the reservior cap back on and tighten it down before any pressure will be felt at the lever.....

not sure thats true? as long as the res isn't dry you should get pressure.

It's not true... the reservoir is just that, a reservoir. The cap just keeps extra fluid from spilling out/contaminate from getting in the reservoir. The master cylinder is what generates pressure in the line down to the caliper for braking.

meh. when i do brake work and have the cap off, i can pump the lever all day long and get no action at the caliper. even with proper bleeding. once i have my reservoir cap back on, then things will work properly. brakes are closed systems, so i would imagine leaving the cap off would ultimately leave this closed system...open. open system, no worky.
imagination and reality are two different things.  the reality is, the level of fluid in the reservoir creates the closed system when upright.  with the fluid level being over the minimum level it disallows the ingress of air into the system.  what you imagine however I cannot help with.
Title: Re: Clarifying procedure for changing front brake line
Post by: slipperymongoose on October 24, 2012, 08:04:45 PM
Yeah I agree tapping the lines and fittings gets your air out, and again long as you have fluid about your minimum line you can have your resivour cap off.
Title: Re: Clarifying procedure for changing front brake line
Post by: noworries on October 25, 2012, 02:18:12 AM
And there is the old tip of - after you have bled the system - pulling the brake lever back hard against the bar and securing it overnight in that position with a robust cable-tie. Have no idea why, but it seems to add a final, rather effective dimension to the brake bleed. Like it 'cos it involves no extra real work on a GS500 owner's behalf!
Title: Re: Clarifying procedure for changing front brake line
Post by: kyled25 on October 25, 2012, 04:30:38 PM
Quote from: dry_humor on October 24, 2012, 07:33:46 PM

meh. when i do brake work and have the cap off, i can pump the lever all day long and get no action at the caliper. even with proper bleeding. once i have my reservoir cap back on, then things will work properly. brakes are closed systems, so i would imagine leaving the cap off would ultimately leave this closed system...open. open system, no worky.

LoL well that's not normal man, you need to rebuild/replace your master cylinder  :icon_eek:
Title: Re: Clarifying procedure for changing front brake line
Post by: Funderb on October 25, 2012, 05:05:11 PM
so i accidentally dropped the bike while parking the other day, and after that the front brake was super firm and felt great?

Seriously.

also, its doesn't matter how good she looks, and how little she is wearing, pay attention to what you're doing.
That being said, not even mad.
Title: Re: Clarifying procedure for changing front brake line
Post by: kyled25 on October 25, 2012, 07:00:38 PM
lol, reminds me of the old televisions you had to smack the side of to make the picture clear