Surge Brake Problems

[Mellisa7]

I have a 1996 Rinker Captiva 232 that I tow on a Haulrite trailer with surge brakes on both axles. The brakes were inspected, rebuilt the wheel cylinders, cleaned and repacked the bearings this spring. The brakes have been bled, and adjusted properly as I have done every year with this boat since 1996. The brakes work great. Stops perfectly and releases perfectly.
Here is the problem. I back the trailer down the ramp and unload the boat. I park the truck and trailer in the parking lot and everything is fine. When I come back at the end of the day the brakes are locked up on the trailer. If I back up the wheels turn with some force but forward it just drags the wheels.. So I have to drag the tires across the lot and back down the ramp... Once I get the boat on the trailer it seems to work fine??????
When I pull the empty trailer out of the water the wheels turn completely free, but when I return hours later they are locked up????
What the heck is going on here?

 

[fhhuber]

Sounds like the spring is not providing adequate tension to release the brakes when the trailer is not loaded with the weight of the boat.

 

[Mellisa7]

I understand what you are saying, but it works fine when pulled out of the water without the boat. It works fine all the way to being parked in the lot for the day. Completely released rolling free.
Locked up tight when I come in for the day to reload the boat?????

 

[Horigan]

Sounds like a combination the master cylinder not fully releasing and a little bit of air in the lines that expands when it sits in the sun. Dipping the trailer in the water cools the fluid, the fluid contracts, and the brakes release. Check the mechanism in the coupler and grease all the moving parts. Rebleed the system. If it still persists, try a new master cylinder.

 

[Mellisa7]

I considered air in the lines expanding.. Also considered the brake shoe lining absorbing water and expanding????? I have never seen anything like this

 

[mike_i]

I've had this happen to me too, Are you launching in fresh or saltwater? Disc or drum brakes?

 

[Mellisa7]

Fresh water, Drum brakes, surge, both axles

 

[Mellisa7]

In the past years, this would happen occasionally. All I had to do was back up a couple feet, it would break loose and good to go.... Last two times out this year would not release. Drag tires across the parking lot . Everybody stares, crazy

 

[dingbat]

I considered air in the lines expanding.. Also considered the brake shoe lining absorbing water and expanding????? I have never seen anything like this

The math does not support the either hypothesis.

The volumes and temperatures involved don't add up to a hill of beans.

I'm thinking the vent on your master cylinder is restricted or clogged...or you've overfilled the reservoir.

Didn't do the math, but the volumes and temps involved hold some promise.

 

[bruceb58]

How old are the wheel cylinders? Very easy for them to hang up with a little corrosion. No way air in a system would cause an issue. Normal drum brake fluid pressure pressure is on the order of hundreds of PSI and there is no way a small amount of air would cause more than a slight increase.

 

[mike_i]

do you know which tires are being dragged? sounds like maybe a wheel cylinder problem, it would be good to know which wheels are locking up of if it's all of them.

 

[kenny nunez]

Try backing the adjuster wheel off by 5 notches.

 

[NYBo]

This sounds like another testimonial for disk brakes!

 

[Mellisa7]

Master Cylinder is NOT overfilled. The VENT hole in the cap is clear and not clogged. I took tongue mechanism apart. All the rollers are round rust free with no flat spots. I did grease everything and put it back together. So far, I can find nothing wrong?????

 

[bruceb58]

Have you checked your wheel cylinders that they don't hang up? You can pull the shoe/s off teh cylinder and pull back the rubber to bake sure he bore is smooth inside.

Do both wheels skid or only one?

Have you pulled the drums to actually look inside?

 

[StingrayMike]

Probably need to replace the piston in the tongue of the ttrailer. The reason why it works backing down and out of the ramp is because the piston is fully extended due to the angle of the ramp and weight of boat on trailer, then having to pull trailer up the ramp against the force of the water.

I think some pistons have adjustments, but you more likely just need to replace

 

[bruceb58]

The piston is used as a damper and when they fail, they typically don't dampen anymore. They rarely get stuck but there is always a first time.

 

[Mellisa7]

The wheel cylinders have been cleaned , honed, and rebuilt with all new rubber. All 4 wheels skidding. Its a crazy thing. Brakes work great all the way to the lake. Brakes do NOT hang up after launching the boat. Roll completely free. Locked up tight the last two times out when returning to load the boat 8 hours later??????

 

[Mellisa7]

Are you talking about the little mini shock absorber? I pulled it in and out when I greased the rollers and seems fine. Was replaced a couple years ago

 

[dingbat]

What type of brakes?
Self adjusting?
Free backing?

I still think the brake shoes are out of adjustment (too tight-15-20 clicks from touching). To discredit this theory, jack up each wheel and give them a spin. The wheel should spin a revolution or two unaided. Actuate the coupler and try it again. If it locks, you need a few more clicks out. Repeat until resitance (wheel) before and after actuation is the same

If it passes that test, disconnect brake line at actuator before your next putting. If they still hang, you've eliminated the coupler equation.