Brake fluid disappearing

[fiddlebick]

My brother has a Hoosier pontoon trailer with hydraulic drum brakes, and he asked me to post a question for his problems. The reservoir was low last summer, so he added brake fluid, and we were doing some maintenance checks this week and noticed the reservoir was low again, looks to be nearly empty. The lines are run inside the trailer tubing, and we haven't noticed any leaks as of yet. I know a full reservoir has very little capacity, and we have not pulled the wheels off yet for an inspection, but wouldn't you think there would be a visible leak somewhere? Its sitting in a pole barn on a concrete floor... Just thought we would get some thoughts on this.

[BillieS]

My brother has a Hoosier pontoon trailer with hydraulic drum brakes, and he asked me to post a question for his problems. The reservoir was low last summer, so he added brake fluid, and we were doing some maintenance checks this week and noticed the reservoir was low again, looks to be nearly empty. The lines are run inside the trailer tubing, and we haven't noticed any leaks as of yet. I know a full reservoir has very little capacity, and we have not pulled the wheels off yet for an inspection, but wouldn't you think there would be a visible leak somewhere? Its sitting in a pole barn on a concrete floor... Just thought we would get some thoughts on this.

There may not be a leak. As the pads wear down the fluid will fall taking up the space in the reservoir. It is a closed system and cannot have air in it. If/when you put new pads on, you will end up having to remove that fluid. Providing there is not leaks.

[fiddlebick]

The pads wouldn't wear that quickly in about 10 short pulls to the river last year...I wouldn't think...but like I said we haven't pulled the drums yet either.

[curtiscapk]

Are there any holes on the bottom of the trailer frame that the fluid would leak out of it there was a hole in the line???? My guess is it has a pinhole leak and fluid is holding up inside the frame.. anyway to look in there?

[cwag911]

He said it's got DRUM brakes and brake fluid doesn't disappear. I'd pull the wheels and look at the wheel cylinders. Pull back the dust caps on the cylinders and I'll bet it's wet.

[fiddlebick]

Update, upon further inspection while preparing to bleed the brakes, we found one of the rubber lines was rubbing the brake drum behind the wheel, and had worn thru to the lining inside. Still it wasn't wet until I really put hard pressure on the actuator mechanism...then a few drops would squeeze out. We ordered the brake line from Hoosier for 20 bucks plus shipping, and will get back to it next week. Its still possible that a wheel cylinder may be leaking as well, but I bet the brake line is the only culprit. In this case it was as simple as calling the Hoosier number, as the line has a special fitting on the opposite end of the brake drum fitting. It was nothing we were going to find locally I am sure.