brake fluid reservoir

[egclassic]

How do you clean a neglected brake fluid reservoir?
The boat I recently purchased has been well maintained, however, the trailer brakes have not. They were not even working when I bought the thing. I filled the empty brake fluid reservoir with clean fluid and began to bleed the system. Never could get the fluid to run "clear" but at least I have brakes now.
Do I just keep passing clean fluid through it until it clears? Or is there something I can run through it to help clean the system?

Thanks

 

[NYBo]

Re: brake fluid reservoir

Your could use compressed air to blow out the system (keep the pressure low). However, if you've already run a lot of brake fluid through the system and you are still getting contaminated fluid at the bleeders, something probably need to be replaced. What color is the fluid coming out?

 

[egclassic]

Re: brake fluid reservoir

The fluid is dark, dark brown almost black. I have flushed about a pint of new fluid through it, not sure if its enough to have thoroughly flushed the system.

 

[dockwrecker]

Re: brake fluid reservoir

Brake fluid will turn black as it's exposed to moisture. If the system was allowed to go bone dry in the past, it's probably full of rust also. The question also begs "where did the fluid all go in the first place". Have a hard look at it after towing the trailer around for a few miles and find the leak(s). But I'd bet a new master and wheel cylinders are in your future.

 

[egclassic]

Re: brake fluid reservoir

I have ordered new drum brake assemblies for both sides as I found that one of the wheel cylinders is sticking, enough to cause just enough drag to heat up the entire hub.(bearings already checked and repacked)
Other than that, the brakes work very well. The inside of the master cylinder is rusty and thats what I was asking here, is there anything that will clean it out?
I have a feeling that the previous owner may have drained the fluid and used it without brakes to avoid spending money. When I picked it up and brought it home, every time I'd stop and then go again, you hear/feel the coupler move against the weight of the boat.

 

[NYBo]

Re: brake fluid reservoir

You didn't mention rust in the original post. I wouldn't trust any of the hydraulics, Time to replace the master cylinder, lines, and wheel cylinders, IMO.