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Raptor 700 Information => 700 Maintenance => Topic started by: Colorado700R on March 03, 2009, 05:45:38 PM

Title: uneven front braking
Post by: Colorado700R on March 03, 2009, 05:45:38 PM
I've been trying to fix a breaking issue for quite awhile now, and I'm stumped.  The left front tire stops and locks quickly, the right rolls father then eventually stops.  The more weight I apply to the front, the worse it is.  I want to go riding Saturday, but this condition causes a wicked left yaw to the quad under braking.


I've checked the lines, master cylinder, calipers (pads and piston operations), and bleed almost a full can of brake fluid using the clear tube method (No bubbles) right side only open.


Like I said, according to the clear tube, there's no trapped air, but then what could be the issue ???

:mad:
Title: Re: uneven front braking
Post by: Krandall on March 03, 2009, 07:03:37 PM
Sounds like you may have a weak master cylinder had that on the taurus the saurus. my drivers side when applying brakes would grab harder than the passenger side. replaced the passenger side all was well.
Title: Re: uneven front braking
Post by: Livingmylife93 on March 03, 2009, 07:04:29 PM
Cna't tell you much more than mine does it to... But not as bad as your talking about, just slightly.
Title: Re: uneven front braking
Post by: Colorado700R on March 03, 2009, 07:15:27 PM
Quote from: Krandall on March 03, 2009, 07:03:37 PM
Sounds like you may have a weak master cylinder had that on the taurus the saurus. my drivers side when applying brakes would grab harder than the passenger side. replaced the passenger side all was well.

We only got one master cylinder on the front brakes for the rappy.  On the handlebars.  I think I might have dirt clogging the right caliper fluid path ???
Title: Re: uneven front braking
Post by: Kamakazi on March 03, 2009, 09:10:07 PM
since i cant really see how any dirt got into a sealed braking system, it would lead me to believe that there is something wrong with the rubber hose, wether a chunk inside broke off, or it is seperating or colapsed.  gotta remember those brake lines take alot of beating too.  id also take off the caliper and try to drain/clean that as well.
Title: Re: uneven front braking
Post by: Blair on March 03, 2009, 10:52:35 PM
Quote from: kamakazi on March 03, 2009, 09:10:07 PM
since i cant really see how any dirt got into a sealed braking system, it would lead me to believe that there is something wrong with the rubber hose, wether a chunk inside broke off, or it is seperating or colapsed.  gotta remember those brake lines take alot of beating too.  id also take off the caliper and try to drain/clean that as well.

i was thinking the same...

make sure there are no bubbles in the brake line as well...

i put braided lines on mine and it made a world of a difference... its like an aftermarket brake system...
Title: Re: uneven front braking
Post by: DL700 on March 03, 2009, 10:54:09 PM
my right does the saame....when i switched to +2 arms and braided lines it never bleed right...
Title: Re: uneven front braking
Post by: Krandall on March 04, 2009, 06:10:41 AM
Quote from: Colorado700R on March 03, 2009, 07:15:27 PM
Quote from: Krandall on March 03, 2009, 07:03:37 PM
Sounds like you may have a weak master cylinder had that on the taurus the saurus. my drivers side when applying brakes would grab harder than the passenger side. replaced the passenger side all was well.

We only got one master cylinder on the front brakes for the rappy.  On the handlebars.  I think I might have dirt clogging the right caliper fluid path ???

Sorry, I meant caliper :)     


The one thing you could do is strip the lines down completely and either replace or blow the lines out.
Title: Re: uneven front braking
Post by: Peelz on March 04, 2009, 06:30:16 AM


hose lost shape, and flexes under pressure? That or a clog.
Title: Re: uneven front braking
Post by: Colorado700R on March 04, 2009, 11:25:49 AM
Quote from: Krandall on March 04, 2009, 06:10:41 AM
Quote from: Colorado700R on March 03, 2009, 07:15:27 PM
Quote from: Krandall on March 03, 2009, 07:03:37 PM
Sounds like you may have a weak master cylinder had that on the taurus the saurus. my drivers side when applying brakes would grab harder than the passenger side. replaced the passenger side all was well.

We only got one master cylinder on the front brakes for the rappy.  On the handlebars.  I think I might have dirt clogging the right caliper fluid path ???

Sorry, I meant caliper :)     


The one thing you could do is strip the lines down completely and either replace or blow the lines out.

I think the blockage is in the caliper itself.  Fluid flows freely out of the hose without resitance, but I think I might have picked up some dirt from where the union joint was loose way back when.  Maybe that dirt traveled closer to the pistons and is restricting flow???
Title: Re: uneven front braking
Post by: Krandall on March 04, 2009, 12:39:57 PM
Hmmmmmm, it would have to be quite a bit of dirt though. I guess you could loosen both of the bleeder valves putting a clear tube on each side say... 2' long. Pull the brake lever and measure how much fluid each side got within the tube. If there was a block in one side, it should be significantly less.
Title: Re: uneven front braking
Post by: Jamie700R on March 04, 2009, 01:25:32 PM
That happened to me and drove me insane. I eventually replaced the brake pads rebled the lines and it resolved the issue.
Title: Re: uneven front braking
Post by: Colorado700R on June 28, 2009, 09:51:34 AM
So....

Finally I have even braking again. 

All-in-all I replaced the brakelines, bleed them 5000 times :mad: , and replaced the brake pads (thanks KB motorsports)

The brake pads were the culprit.  They shown no signs of uneven wear, and looked to have plenty of life left on them, but as soon as I put the new ones on, the problem was fixed.

FYI, I installed Speedlinez brand brakelines.....wow, major difference in feel.  If you breath on my brake lever you almost endo :nod:
Title: Re: uneven front braking
Post by: Krandall on June 29, 2009, 10:19:23 AM
dang, that's wierd! must have been 2 different brake batches or soemthin.
Title: Re: uneven front braking
Post by: Spider/Paleface513 on September 08, 2009, 07:14:58 AM
Quote from: Krandall on June 29, 2009, 10:19:23 AM
dang, that's wierd! must have been 2 different brake batches or soemthin.
My rappy does this but not bad,you can only tell if you try to lock the brakes up. The left front one stops first. From working on cars I'd beleive it to be the brake lines. I've seen this in cars the lines get weaker over time brakefluid softins rubber. When that rubber gets soft it'll swell up. I've seen some when you push/pull brake lever the fluid runs thru the linethen pushes the piston in the caliper,if the line is weak when you push instead of pushing on brake piston line swells up leaving less pressure on the piston. The new braided hose don't flex at all so breaks got killer grip now instantly. It's my next project to change the brakes and lines I'm switching to one those wavey rear rotors also will keep posted after words.
Title: Re: uneven front braking
Post by: Colorado700R on September 08, 2009, 07:30:10 AM
try new brake pads first, mine looked absolutely fine, but they were the culprit. :mad:
Title: Re: uneven front braking
Post by: Spider/Paleface513 on September 08, 2009, 08:43:41 AM
I'll do that and check back in afterwards.
Title: Re: uneven front braking
Post by: francky2000 on December 08, 2009, 07:30:34 AM
check the small nut 3JD-25961-00-00. the pad lean on it and can dig into it preventing the pads to move freely.