Front Brake Fluid Disappearing

1284 Views 27 Replies 7 Participants Last post by IndyVictory, 9 mo ago

Vinish

Discussion Starter · 9 mo ago

Over the last 3 weeks, I have had to put brake fluid into my front brake fluid reservoir twice. The brake fluid is clearly leaking out somewhere. There are zero drips under the bike even when sitting for a few days. The fluid is probably only leaking when the brake lever is pulled and thus puts pressure into the system. I have examined the banjo connections at the reservoir and at the two front brake calipers. There is not leakage at these locations. I can't tell for certain but as best I can tell, there is nothing leaking from around the pistons in the front calipers. I looked under the rear bumper at the ABS brake module and see nothing leaking there although you can only see the bottom of this module. I am not even sure that this ABS module has brake fluid lines running to it. Perhaps it is only electronics. There are no drips under the bike but, as mentioned, the leakage probably only occurs when the lever is pulled.

Anyway, from where could the front brake fluid be leaking? Any recommendations on how to find the leakage location? Thanks.

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IndyVictory

· #2 · 9 mo ago

Pull seat.

Lines run from reservoir along top of frame to the ABS unit on the back then forward to the brake calipers.

You can zip tie the lever to put pressure into system then should be easier to find the leak.

Let us know what you find.

Reactions: 2

NOEMTZ

· #3 · 9 mo ago

Pull tank and seat and inspect lines.

Reactions: 3

Vinish

Discussion Starter · #4 · 9 mo ago

I pulled the seat to start with and immediately discovered the leak. The aftermarket rider's backrest bracket was rubbing on one of the two front brake lines that runs under the seat. It wore a small hole in the line in this area. The hole is very near the place where the metal line runs under the rearmost of the two metal cross-pieces of the rear fender.

Can anyone offer suggestions for how to repair or replace this leaky metal brake line? It appears there are some sort of connections on this metal line. One is under the rear part of the tank while the other will be much harder to access as it is under the rear fender. These look like some sort of one-time use compression fitting but I am not sure.

Can a shade-tree mechanic splice in a section of metal tube? If so, how? If I could buy this section of brake line, could a shade-tree mechanic disconnect the current compression fittings and splice in new ones? Thanks for any advice you can offer.

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IndyVictory

· #5 · 9 mo ago

Should be able to use standard auto brake line.

Or buy it from Polaris for $372, that is full front brake lines.

Brake hard lines use flared ends and compression nuts. I've seen it done but don't own the tools for it myself. Should be pretty straightforward to cut out six inches and flare ends to connect in a patch. Check YouTube and play around with some line off bike for practice and you'll be fine. The brake line tools might be available to rent from auto parts store. They do rent out many tools. That would save you cost of buying.

Reactions: 1

normthenomad

· #6 · 9 mo ago

Any competent hydraulic hose shop can make one in less time than it took me to type this. You can buy the tools for under $50 but it's a pain to make any bends.
The NAPA store here in a small town in AZ makes them.
I ride Buells as well so I've had to have assorted lines made on occasion.

Reactions: 1

Vinish

Discussion Starter · #7 · 9 mo ago

It appears that you cannot buy just a part of the front brake hose system. You have to buy the entire thing (lever to ABS unit and ABS unit to both front calipers) for ~$570. The hole in the steel brake line is right next to a rear fender cross brace to tonight I took off the saddlebag mounting brackets and the rear fender. This gives me access to the offending line.

My plan is to:

Cut the line at the existing hole leaving me two metal hose pieces
Bend the two hoses up slightly to allow me to work on them
Use a tubing cutter to cut each hose back a suitable distance
Buy (or rent or borrow) a brake line flaring kit (cheap on Amazon at ~$20)
Buy four tubing nuts and two connectors
Slide tubing nuts onto the bent up ends
Do a double flare on each hose end
Buy some 3/16" brake line tubing and cut the proper length to fit between the cut ends. This could be the most tricky part as there will be connectors and double flares on each end so I am not sure how long to make this piece to fit a given distance between the firmly mounted existing double flared hose ends. I might have to do some trial and error here. Fortunately, the tubing is cheap.
Do a double flare on each end of the new 3/16" brake line
Connect everything together
Bleed the brake system

What do you think of this plan? Does anyone see any problems? Does anyone have a reference document about what length tubing to use with double flare and connectors to fit into a specific size gap?

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IndyVictory

· #8 · 9 mo ago

Don't pay full price, you have to add to cart to see real price on part websites. Just FYI for future.

Your plan is same thing I would do.
Remember you'll be working around that backrest so keep that in mind with where you cut your lines.
Also take steps to prevent it recurring, not sure what backrest you have, but I have not read of anyone having issues with wearing holes in brake lines.

Can you get picture of your problem and the fix?
It could be helpful to the rest of us.

Vinish

Discussion Starter · #9 · 9 mo ago

I will work on pictures tomorrow. Ordered all the parts (tubing, nuts, unions, and flaring kit) today from Amazon but will not be here until Tuesday or Wed. Total price was ~$47. Have my work cut out for me. Thanks for your ideas and support.

IndyVictory

· #10 · 9 mo ago

I hope it all goes smoothly.

Looks like eBay has a few of the hard lines from salvage bikes but they are $150+.
Who knows how that will survive being folded and shipped.

djh3

· #11 · 9 mo ago

I probably would have went back to where ever a connector was and measure out and just went with braided line. But it sounds feasible.

IndyVictory

· #12 · 9 mo ago

That can work with the hard lines too. Connection at the ABS unit and there should be one at front somewhere.

Vinish

Discussion Starter · #13 · 9 mo ago

The ABS unit has a threaded connection but all of the other connections in the stock line appear to be some sort of crimped on fitting between the rubber flexible portions and the metal tubing portions.

Vinish

Discussion Starter · #14 · 9 mo ago

Here are some pictures of the current situation with the hole in the metal brake line.

Picture 1 is with the fender in place and the rider backrest bracket in place. The backrest is the Victory brand one so I am quite disappointed in Polaris for the design of this bracket that rubs on a brake line as well as on the wire bundle on the opposite end of the bracket.

Picture 2 is a closer view of the bracket where it rubs on the metal brake line. You can clearly see where the leaking DOT4 brake fluid has damaged the red paint on the fender cross brace as well as the black paint on the frame. The hole is under the bottom rightmost point of the backrest brace. The blue painters tape is something I am using to mark the locations of the fender cross braces.

Picture 3 is a closeup of the hole in the brake line. The hole is indicated by the red arrow (duh

)

Picture 4 is of the entire underseat area with the brake lines visible. The rag is just there to sop up the leaking brake fluid.

Picture 5 is the same as 4 but the arrows show where I plan to bend the tubing upwards to allow me to flare the ends. I will cut the tubing at the current hole. The red rectangles show where I plan to put the unions/nuts. I have verified that I have room under the seat for these. I am concerned about the unions/nuts rubbing on the other brake lines so I will have to put something around them to prevent this.

Picture 6 shows the stock connections in the brake line. The only connections in the stock brake line are where the flexible rubber hoses and the metal tubing join. This is one example of these connectors. They must be some sort of crimped on connector as there is nothing that would be turned by a wrench. This connector is on the front brake line from the lever just before it goes into the ABS unit.

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Vinish

Discussion Starter · #15 · 9 mo ago

I recommend that anyone with a rider's backrest remove their seat and look at their backrest bracket to determine if it is rubbing on any brake lines or wire bundles. I plan to cut off the triangular shaped points on both ends of my bracket. They are not structural and serve no purpose other than to damage the brake line.

normthenomad

· #16 · 9 mo ago

djh3 said:
I probably would have went back to where ever a connector was and measure out and just went with braided line. But it sounds feasible.

+1^^^^

IndyVictory

· #17 · 9 mo ago (Edited)

I have washers stacked under my backrest bracket to keep it off the wiring and brake lines.

You have a lot of brake fluid to clean up.
Brake cleaner can take care of it but you'll need to follow that with something less harsh.

I don't know if the skin is steel or aluminum but rattle can would fix under seat area easily.

Reactions: 1

wspollack

· #18 · 9 mo ago

Vinish said:
I recommend that anyone with a rider's backrest remove their seat and look at their backrest bracket to determine if it is rubbing on any brake lines or wire bundles. I plan to cut off the triangular shaped points on both ends of my bracket. They are not structural and serve no purpose other than to damage the brake line.

Is this on my former XCT, and if so is it the result of the Utopia backrest I bought for the bike?

Vinish

Discussion Starter · #19 · 9 mo ago

Yes it is on your former XCT but no, it is not from the Utopia backrest. My wife liked the Utopia better than the Victory brand backrest that was on her bike so we swapped them. It is the Victory brand backrest mounting bracket that caused this problem. A bad design from Polaris.

Reactions: 1

wspollack

· #20 · 9 mo ago

Vinish said:
Yes it is on your former XCT but no, it is not from the Utopia backrest. My wife liked the Utopia better than the Victory brand backrest that was on her bike so we swapped them. It is the Victory brand backrest mounting bracket that caused this problem. A bad design from Polaris.

Ah, thanks for the explanation. I was worried that I was responsible.

Good luck on the repairs (which is the type of work I've never attempted, either).

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