Towed the trailer with the Dodge today, and smelled something wrong, so pulled off right away, nothing abnormal other than a few drips from the reservoir, dripped onto the exhaust manifold and were burning, hence the smell. Not a line leaking either. I checked it two days ago and hadn't driven it since, it was right up to the MAX line, and the brake fluid was dark, I know it is not good to be dark, it hasn't been changed for years, and I know that isn't good either, every time we had brake work done (and it wasn't me doing it either) they just bled what they needed to instead of replacing the fluid.

Today the reservoir got over MAX, brake fluid filled it up out of nowhere?????? Leaked out from top of reservoir, then it got below where it could leak out the top and still leaking!!!!!! Brakes feel and operate fine, but they certainly don't have as much assist as they used to, but can stop safely, albeit not as strong of braking as they used to have.

Pics attached of fluid colour, and leak as best as I could, I'm using DOT 3 Enhanced brake fluid, which isn't cheap, costs $6/pint. I lost about 3/4 cup of brake fluid. It is clear/amber in colour.





Also of note I about the RWAL, as it wasn't working anyways. May still have power but no VSS or rear diff speed sensor signals or signals from brake cylinder valve.

Any ideas?

 

if the fluid is old and crappy, it probably has a lot of water in it, and if pulling the trailer with the brakes getting hotter than hell, it might have boiled the fluid.

flush the system and see if it does better.

 

Brakes actually never got too hot, what did get hot was one of the rear axle bearings, but flushing the system, would it help with the leaking? I'm more concerned about the leaking than the fluid at this point.

 

I think you missed the part about the water getting in it. Brake fluid likes to attract and hold water, so vaughan is onto something with that. If there is too much water in it, it very well COULD have tried to boil. Flushing would be the only solution if that's the case.

 

I know water could get in, but I'm asking about the LEAK, not about the FLUID. I already know about the fluid.

Now if the fluid could be causing the leak, then I need to know, but no one is saying that flat out.

 

If water contamination is the problem, whats happening is it starts to boil off, and the increased pressure when you release the brake pedal lets it push additional fluid back into the reservoir. Water expands pretty dramatically when it boils..... You don't even have to brake that hard to get the temps up there either, especially when pulling a trailer. Decreased brake performance also points that direction. (though you should get a somewhat spongy pedal as well.)

 

Okay, thanks HY, I'm planning on switching to DOT5 brake fluid since we tow alot. I'll flush the whole system before I add DOT5.

Looks to me like the seal at the bottom of the reservoir on the part where it mates to the master cylinder is what is leaking, so I will probably have to replace the whole thing as it doesn't look like I can buy the reservoir and seals separately.

 

DOT 5 is silicon based, is it not? Bear in mind, that it reacts poorly to non-silicon based fluids... turns into a nice gel...... brakes quit working..... No fun at all.

 

Yep DOT5 is silicon base, that's why I'll flush it out with DOT5 and make sure the system is clean lol...

 

Make sure it is REALLY clean.