CJ- Got air in my brake lines while wheeling..suggestions?

[Johnny X-Ray]

Hello, Last time I went 4 wheeling I managed to get air in my brake lines. Desending back to the road was sketchy :shock:. Could brake fluid sloshing in the master cylinder be the cause? Does this sound plausible? Has it happened to anyone else? If so, does anyone have a fix or maybe a mastercylinder upgrade they could recommend?

 

[JPNinPA]

Usually there is not enough room to shosh and allow the air to reach the opening. Unless you flip or roll.


How do you know you have air in the lines?


Never look down on anyone unless you are helping them up - Jesse Jackson

 

[mark sr]

Low on brake fluid ?? I'd carefully inspect all the lines for leaks.

 

[Johnny X-Ray]

I first noticed the pedal being spongy as we desended back to the main road. I bled the brakes when I returned home and did find air in the lines. Since then I have put many miles on it and have had no issues or puddles in the garage. Im pretty sure that the day I went wheelin I checked the master cylinder for fluid level and all was well. just occured to me that I have not checked the condition of the seal on the master cylinder lid. Maybe thats it? Thanks for answering

 

[JPNinPA]

Was it hot and you were heavy on the brakes and often???
Brakes are a sealed system. Nothing out nothing in. The lid if not sealing will let air and moisture in reducing the boiling point of the fluid causing more bubbles in the lines when worked hard. Its called brake fade. If it sloshed out that is bad and needs to be repaired.
Also lids typically have a rubber seal that expands in as brake pads wear and draws more fluid in.


If air was let in on a regular basis I would bleed out all the old fluid. Moisture is killer and can cause multiple issues.

Do check the lines for pinches or kinks. They are fatal to brake systems.



Never look down on anyone unless you are helping them up - Jesse Jackson

 

[ndnatty]

Is your proportioning valve on the frame? If you have headers might be too close to it, might have caused a leak. Just a thought, but lots of places there could be a leaky connection.


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[Johnny X-Ray]

Thanks Ya'll for your input.. I will re-inspect all my connections this weekend, and yes it was very very hot here on the day it happened and I was on the brakes alot. The brake fade theory fits well.

 

[JPNinPA]

FYI
How to Test Brake Fluid - YouTube


Never look down on anyone unless you are helping them up - Jesse Jackson