Plunger or Master Cylinder stuck on Hydraulic Trailer Brakes?

duponts

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Jun 20, 2005
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17
Hi all. I am working on the boat trailer brakes for a boat that I recently purchased. It has the Titan Model 60 brake Actuator. I was told that to bleed the brakes, I should unscrew the cover plate on the breakaway lever and then pump the lever (using vice grips as a handle) back and forth before bleeding each of the brakes. The problem is that I can barely move the breakaway lever- it appears to be stuck in the back position (away from the cylinder) and will not move forward to depress the plunger to the [COLOR=#DD3C42 !important]spring[/COLOR]to pump the master cylinder. Am I doing something wrong or is there an issue with my master cylinder that I should be concerned about? The push spring looks rusted so maybe it is seized? Any help would be appreciated. Thanks in advance.
 

Bondo

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Apr 17, 2002
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I should unscrew the cover plate on the breakaway lever and then pump the lever (using vice grips as a handle) back and forth before bleeding each of the brakes.

Ayuh,.... Welcome Aboard,..... I use a 2x4x8, stuffed down through the safety chains, 'n Lever the coupler, Aft, pushin' the cylinder in,....
It should move back forward with spring pressure,...

Or, with yer tow unit, block the trailer wheels, back up against the blocks, 'n bleed, roll ahead, 'n repeat,...

Yer's may, or may not be rusted seized,... Can't tell from here,.... ;)

Is there brake fluid or water in the reservoir,..??
 
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duponts

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Jun 20, 2005
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17
So I took the master cylinder apart and there is a push rod assembly like the on in the attached picture. The large spring shows no flexibility and there is a washer at the end (shown on the right of the attached photo below) that does not move. It seems like for the rod to work that the spring would need to be somewhat flexible so that it can be pushed against the cylinder reservoir to activate the brakes. What am I missing here?
 
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UncleWillie

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Oct 18, 2011
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The Titan 60 coupler is rated for up to a 6000lb trailer.
Assuming that you only have a 3000lb load and the spring holds off the brakes for the first 100 lbs of "Surge".
That would mean you would have to be braking at 100/3000 = 1/30th of a g to actuate the brakes.
That is the equivalent of taking a minute and a half (90sec) to stop from 60mph.
Or a full 3 minute stop with a 6000 lb load. ... Mighty gentle!
100 lb of spring pressure is not unreasonable.
Otherwise the brakes would be actuating for every little bounce and drag going down the slightest incline.
Don't expect the spring to compress very easily with hand generated forces.
 

bruceb58

Supreme Mariner
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Mar 5, 2006
Messages
30,454
I had a Dico 60 surge unit. It was very easy to operate the master cylinder with the break away lever and a vise grip on it.
 
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