Mush for a front brake. HELP
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Tourer
Joined: Feb 2007
Posts: 456
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From: somewhere in the swamps of jersey
Mush for a front brake. HELP
I had to drain the front brake reservoir because of a leak from the gasket. Was told that the wrong brake fluid might have caused leak. So dealer sold me dot 5 fluid. Now I have filled reservoir held lever and open bleeder valve. Then tried to tap at caliper and cylinder. But still brakes are total Mush. How do I get the lever back to wherea 1/4 pull engaged the brake. Right now the lever comes all the way to grip. And did the studip dealer give the right fluid. the cover says use dot 4 only. Is there any differnce other than 5 is supposedly less corrosive? But can the fulid be why the brake is Mush... Please help I gotta ride and need a working front brake.
Road Warrior
Joined: May 2007
Posts: 1,620
Likes: 117
From: ARIZONA
RE: Mush for a front brake. HELP
Dot 5 is a totally different fluid than 4 and WILL cause problems. If you dealer sold you 5 saying it was better, they need to have their franchise taken away. HARLEY BRAKE SYSTEMS USE DOT 4 FLUID. (not yelling at you, but just emphasizing the importance). As you stated, it said it on the cover. A gasket leak can be cause by a number of different reasons, but factory fluid ISNT going to cause a leak in it of itself.
DOT 4 is poly elethene glycol based. Different than DOT 3, and DOT 5.1, but essentially the same base compound( I would NOT substitute ANY fluid for another unless specifically allowed in the service manual)
DOT 5 is silicone based. Likely you have messed up a seal or two in the master cylinder, causing your mushy feeling. Mismatching fluids will destroy seals that are VITAL to providing a pressure buildup that in turn puts pressure on the pads and stops you and your bike.
Better figure out who at that dealership sold that DOT 5 to you. Then call the service manager and demand that the dealer replaced EVERYTING in your front brake system for free. Thier f up, they need to be held accountable.
DOT 4 is poly elethene glycol based. Different than DOT 3, and DOT 5.1, but essentially the same base compound( I would NOT substitute ANY fluid for another unless specifically allowed in the service manual)
DOT 5 is silicone based. Likely you have messed up a seal or two in the master cylinder, causing your mushy feeling. Mismatching fluids will destroy seals that are VITAL to providing a pressure buildup that in turn puts pressure on the pads and stops you and your bike.
Better figure out who at that dealership sold that DOT 5 to you. Then call the service manager and demand that the dealer replaced EVERYTING in your front brake system for free. Thier f up, they need to be held accountable.
Outstanding HDF Member
Joined: Jul 2007
Posts: 2,424
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From: Hoboken, New Jersey
RE: Mush for a front brake. HELP
ORIGINAL: ebeattie
Dot 5 is a totally different fluid than 4 and WILL cause problems. If you dealer sold you 5 saying it was better, they need to have their franchise taken away. HARLEY BRAKE SYSTEMS USE DOT 4 FLUID. (not yelling at you, but just emphasizing the importance). As you stated, it said it on the cover. A gasket leak can be cause by a number of different reasons, but factory fluid ISNT going to cause a leak in it of itself.
DOT 4 is poly elethene glycol based. Different than DOT 3, and DOT 5.1, but essentially the same base compound( I would NOT substitute ANY fluid for another unless specifically allowed in the service manual)
DOT 5 is silicone based. Likely you have messed up a seal or two in the master cylinder, causing your mushy feeling. Mismatching fluids will destroy seals that are VITAL to providing a pressure buildup that in turn puts pressure on the pads and stops you and your bike.
Better figure out who at that dealership sold that DOT 5 to you. Then call the service manager and demand that the dealer replaced EVERYTING in your front brake system for free. Thier f up, they need to be held accountable.
Dot 5 is a totally different fluid than 4 and WILL cause problems. If you dealer sold you 5 saying it was better, they need to have their franchise taken away. HARLEY BRAKE SYSTEMS USE DOT 4 FLUID. (not yelling at you, but just emphasizing the importance). As you stated, it said it on the cover. A gasket leak can be cause by a number of different reasons, but factory fluid ISNT going to cause a leak in it of itself.
DOT 4 is poly elethene glycol based. Different than DOT 3, and DOT 5.1, but essentially the same base compound( I would NOT substitute ANY fluid for another unless specifically allowed in the service manual)
DOT 5 is silicone based. Likely you have messed up a seal or two in the master cylinder, causing your mushy feeling. Mismatching fluids will destroy seals that are VITAL to providing a pressure buildup that in turn puts pressure on the pads and stops you and your bike.
Better figure out who at that dealership sold that DOT 5 to you. Then call the service manager and demand that the dealer replaced EVERYTING in your front brake system for free. Thier f up, they need to be held accountable.
chop09..... I would start by bleeding the brakes throughly.....enough so you can sort of flush the old fluid out and introduce the new. If that dont do the trick, it could very well be that there is some sort of conflict between the DOT4 and DOT5, or the DOT5 and the components of your particular system. If the DOT5 caused the failure of any of the parts in the system, I would have the cat that told you to use DOT5 (when the lid says use only DOT4)to step up to the plate and do the right thing.
Cruiser
Joined: Jul 2006
Posts: 185
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From:
RE: Mush for a front brake. HELP
Ebeattie, is pretty much correct, what he forgot to add is that Harley did use DOT 5 fluid up to acouple years ago, I'm just not certain what year it was but since have changed to DOT 4. He also is correct in saying not to mix these fluids. This is really sandbox 101, if you'r master cylinder cap says DOT 4 then use 4. if it says 5 then use 5.
Cruiser
Joined: Mar 2007
Posts: 243
Likes: 2
RE: Mush for a front brake. HELP
Sounds like you've got air in the system. Did you drain completely before you added the DOT 5? My preferred procedure would have been to open the bleeder and let the DOT 4 drain (through a hose attached to the bleeder) and pour in the DOT 5 as the DOT 4 drained. You should be able to tell when the DOT 4 is completely gone when the different color fluid appears through the hose. Using this method would not allow any air into the system. If you drained the system entirely, chances are you have air. Bleed the same as you would a car. Pump the brake lever several times then hold it. While holding it in get a partner to crack the bleeder valve - this will allow air/fluid to escape. Tighten the bleeder and repeat. Do not release the brake lever while the bleeder is open as this will allow air in the system.
Use a hose on the bleeder valve into a can or something to catch the fluid. DOT 5 is not as hard on paint as DOT 4 but don't take any chances. Wash brake fluid that happens to spill or splash on finished surfaces with water immediately.
As for the choice of fluid - I would assume that the dealer would know if DOT 5 will work. I've upgraded to DOT 5 (from DOT 4 or DOT 3) in competitive cars. As someone stated above DOT5 is not compatible with the others so the trick is to get all (ALL) of the old stuff out.
Good Luck,
Don
Use a hose on the bleeder valve into a can or something to catch the fluid. DOT 5 is not as hard on paint as DOT 4 but don't take any chances. Wash brake fluid that happens to spill or splash on finished surfaces with water immediately.
As for the choice of fluid - I would assume that the dealer would know if DOT 5 will work. I've upgraded to DOT 5 (from DOT 4 or DOT 3) in competitive cars. As someone stated above DOT5 is not compatible with the others so the trick is to get all (ALL) of the old stuff out.
Good Luck,
Don
Road Master
Joined: Jan 2007
Posts: 770
Likes: 2
From: East NM
RE: Mush for a front brake. HELP
If you had DOT 3 or 4 in it before, the system has to be cleaned out completely before using DOT5. This is important because mixing DOT 5 with any other fluid results in a blob of jello like stuff. If it has always had DOT 5 in it, you might need to use a vacuum bleeder on it. You can get one with a handpump for under $50, and they are useful for other tasks, so it won't be a one use tool.
Another thing that can cause the same effect as air in the brake line is a rubber hose that's gone soft. If you don't have braided hoses, feel them as you apply the brake hard and see if you can feel them stretching.
Another thing that can cause the same effect as air in the brake line is a rubber hose that's gone soft. If you don't have braided hoses, feel them as you apply the brake hard and see if you can feel them stretching.
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Tourer
Joined: Feb 2007
Posts: 456
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From: somewhere in the swamps of jersey
RE: Mush for a front brake. HELP
Thanks for the input all. Looks like I'm gonna have to go through the mess of draining brake again. I dont know why i used the DOT 5 in the first place. Trusted the dealer. That was my first mistake.
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Road Master
Joined: Jan 2007
Posts: 770
Likes: 2
From: East NM
RE: Mush for a front brake. HELP
If you are going to go through draining, flushing and cleaning out the system, might as well use the DOT5. It is a lot nicer to yoour bike, doesn't eat paint etc. I've heard the reasom HD gave up on it and reverted to DOT4 was because it was too hard to convince customers that there are different fluids and they don't always mix.
Banned
Joined: Mar 2007
Posts: 3,706
Likes: 7
From: Woodstock, Ont , Can
RE: Mush for a front brake. HELP
Clear cut case for buying a manual. As mentioned, get the dealer to replace damaged components. They're suppose to know what fluids go in there. As for bleeding the brakes, sometimes filling from the caliper works better. It's called reverse bleeding. Plenty of info on the internet on how.
Ron
Ron