I should clarify that I only experience this after acsending hundreds if not thousands of feet in a short time. The brakes are not hot when this happens, since I have not used them much, if at all, during the acsent. They have never failed to work, but they do take more pressure from my foot, and feel squishy. If I pump them up, or mash the pedal several times, it returns to normal feel. I assumed this was due to air pressure or atmospheric influence, or maybe the hoses can't contain the pressure as well. We are talking about high altitude trails and passes at 11000 to 14000 feet. Nobody else has experienced this?
Brake fade at high altitude
- Thread starter JK Rocker
- Start date
sipafz
Caught the Bug
Just a thought, check out your booster and supply hose for vacuum leaks. Also check the supply line integrity making sure that the vacuum pressure hasn't collapsed the hose.
Where do you drive up to 14k? I thought that one could only get that high by hiking.
WJCO
Meme King
Good question. Mt Evans and Pikes Peak here can be driven to. Both over 14k. I don't know of any others myself.
sipafz
Caught the Bug
Hiking in Colorado is on the long "bucket list". I hope to get there someday soon!
You can drive to the top of Mt Antero, which is a 14er.
We spend our summers wheeling all over Colorado.
Zstairlessone
New member
This is what I was referring to, the expansion at higher elevations remark. BTW water is pretty incompressible also (it, like brake fluid, does compress some but not enough to notice or affect performance). In fact a lot of nuclear plants will use plain old water for primary system hydraulic fluid, the problem is corrosion control and they maintain a high alkali (base) level to minimize it. Can't do that in a brake system, plus water tries to boil at much lower temperatures for a given pressure... sorry for the digression
Zstairlessone
New member
Thanks! I always thought if it said 3 you could use 3 or 4 but not 5 (completely different type) and if it said 4 you had to use 4 (because 4 has a higher boiling point and if you use 3 it would possibly /probably boil during hard use - I think) . I know you shouldn't mix any of them because it may cause corrosion or weird things. When I was younger I used to 'update' brakes by switching to 4 from 3 with a full flush - no more.
I just experienced the same issue at high altitude, 10k-11k in the Sierras and White mountains.
The fluid was full and found no leaks, The brakes returned to normal at lower altitudes.
I plan on replacing the fluid in the next few weeks but will be unable to verify if that fixes the problem.
The fluid was full and found no leaks, The brakes returned to normal at lower altitudes.
I plan on replacing the fluid in the next few weeks but will be unable to verify if that fixes the problem.