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I have a 2013 Ranger Crew 800 that I took on a drive up a canyon recently. On the way down there was a period during which the brake pedal would depress all the way to the ground and even then provide very little stopping power. With my whole family in the vehicle, it was quite scary, but we were able to ride it out and after a while the brakes returned to normal. Some searching online suggests that water has crept into the brake lines (which are braided steel cable sheathed) over time and that this water probably boiled, making it compressible. I understand this termed brake vapor lock. So, questions:

1. Do the symptoms I describe sound like "brake vapor lock"? i.e. does it sound like water is in the lines or does this sound more like air or something else? (Also, is brake vapor lock the proper term for boiling water in the brake lines?)
2. What is the appropriate remedy for this? Is it bleeding the lines, or do you have to do a full flush of the lines (and is there any functional difference between the two - bleeding and flushing)?
3. Is there a way to get decent engine braking with the CVT? It felt like there was very little slowing due to the engine, but it's hard to tell.
4. Relatedly, what's the best way to descend a relatively steep or a long hill? In High because you will likely be going >10mph, or in Low and on the brakes in order to try and keep from going >~10mph? I assume not Neutral and just on the brakes, right?

Many thanks in advance for any insights you can provide!
 

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I have a 2013 Ranger Crew 800 that I took on a drive up a canyon recently. On the way down there was a period during which the brake pedal would depress all the way to the ground and even then provide very little stopping power. With my whole family in the vehicle, it was quite scary, but we were able to ride it out and after a while the brakes returned to normal. Some searching online suggests that water has crept into the brake lines (which are braided steel cable sheathed) over time and that this water probably boiled, making it compressible. I understand this termed brake vapor lock. So, questions:

1. Do the symptoms I describe sound like "brake vapor lock"? i.e. does it sound like water is in the lines or does this sound more like air or something else? (Also, is brake vapor lock the proper term for boiling water in the brake lines?)
2. What is the appropriate remedy for this? Is it bleeding the lines, or do you have to do a full flush of the lines (and is there any functional difference between the two - bleeding and flushing)?
3. Is there a way to get decent engine braking with the CVT? It felt like there was very little slowing due to the engine, but it's hard to tell.
4. Relatedly, what's the best way to descend a relatively steep or a long hill? In High because you will likely be going >10mph, or in Low and on the brakes in order to try and keep from going >~10mph? I assume not Neutral and just on the brakes, right?

Many thanks in advance for any insights you can provide!
I've never heard the term "brake vapor lock". think what you're experiencing is brake fade and that happens when the brake fluid gets so hot it begins to boil and turns to vapor. Brake fluid is designed to operate at high temperatures without boiling so brake fade is not as likely. The problem is that with the exception of Silicone brake fluid, all others are hygroscopic, they absorb moisture. The mositure comes from the atmospehere and through exposure to liquid water. Master cylinders are vented to the air so some moisture can get in. It has been said that moisture can also get through the rubber hoses used for brake lines microscopically over long periods of time. When your fluid is old it likely has absorbed moisture which lowers the boiling point and you end up with brake fade under extreme conditions.
The remedy is flushing the lines and using new fluid of the recommended type. It's good policy to flush brake lines annually although few people do it.
When brake pads are worn there isn't as much mass to dissipate heat so fade can come earlier.
Polairis offered a descent control option on some models. I don't know much about it or if it can be retrofitted. I believe the front differential is involved and perhaps the ECU as well as some hard parts.
You can add a Duraclutch which will provide engine braking. I have one and I like it very much. Engine braking and smoother engagement than OEM and much less belt wear.
I would never descend a hill in neutral. Depending upon the grade I use high or low range. With the stock clutch you can heel and toe the gas/brake to keep the clutch engaged and get some engine braking.
Edited for spelling 15:49 EST
 

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Most automotive brake systems have a recommended change interval of 3 years! They don't often get the abuse these rigs get
Pyro pretty much has got it in the bag on this one.
Now having had h20 in the system you may get a full inspection of your disc pistons and bores because if they get rough your going to have more brake issues soon.
 

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The Duraclutch is spendy, but it is a major upgrade. My first impression was smoooth, and from 20 mph in low gear on a hill simply lift your foot and it will bring you to almost stop. Mine is on a 2019 Ranger 900XP.
 

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Thank you all so much, this is super helpful!

I'll be checking the brake pads, rotors, and pistons. To clarify, is flushing the brake lines basically the same as bleeding them but putting more brake fluid through?

The Duraclutch sounds really good! Have to decide if it's worth putting on the 2013 machine r waiting for its replacement...
 

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A good way to flush brake lines is to "suck" new fluid through them from the master cylinder via the bleeder screws after removing what you can from the reservoir as summerman suggests above. Start with the wheel farthest from the master cylinder (usually right rear) then the next closest, the next and the closest (usually left front) last. There are several tools that can be used to suck fluid through the lines. Mityvac is one, and there are others. Some use compressed air to form a vacuum via a venturi effect. Pressure bleeders are also available but generally more expensive than vacuum types and require adapters to fit various master cylinders. Both types save a lot of pedal pumping and assure the best purge of fluid, pressure types being marginally more effective becasue no air can leak in via the bleeder screw threads or hose attachment to the bleeder nipple during the bleeding operation. With a little care the vacuum type work just fine. Both effectively use pressure to force the fluid through the system. The vacuum type uses atmospheric pressure while the pressure type uses pressure above atmospheric pressure.
Harbor Freight, Amazon and other places carry bleeders.
 

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Another instance where youtube will probably have several ways to do the job down to a simple tube and reservoir.
The rangers system is small so should not take to much fluid or time if you just have someone to help pump.
Hand brake bleeder vacuum tool is $25 at Harbor Freight.
I am getting ready to do my Xterra and F350 and the truck will take over a quart to get it done right.
 

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FYI, it's also possible that your Master Cylinder is on it's way out. When the "rubber" parts inside the MC deteriorate and/or the metal parts have pitted and corroded due to moisture in the system, fluid is allowed to leak past seals, internally, which causes pressure to the brake calipers/wheel cylinders (if equipped) to be lost and braking is reduced as the brake pedal goes all the way to the floor.
This may not be the case, but the possibility exists. If the experience you had was intermittent and went away after the brakes cooled it's likely contaminated fluid and/or worn pads. If not, the MC is a likely suspect unless you see fluid leaking at the calipers/wheel cylinders (drum brakes).
My advice, check pads and replace as necessary, inspect for leaks at the MC and calipers, flush brake system and go from there.
 

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Normally a bad M/C will drop to the floor after being pressed for the 1st time after it's been sitting for awhile or when using steady pressure on the pedal for a while ( like when sitting at a red light) let off and press again it will have a hard pedal.

Do your research not all fluids are compatible but you can upgrade to a higher boiling point to help with brake fade!
dot brake fluid compatibility - Google Search
 
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