lockout solenoid problems

[jkru]

I have a trailer in which I had upgraded from drum to disc brakes at a Marine place who didn?t know what the hell there doing; Including but not limited to using the same master cylinder that was used for the drum brakes. I am now trying to fix this abortion of a job. One of the problems I am having is with the KIP lockout Solenoid among other things. The boat is a 28' searay around 9000lbs. The lockout is not working the brakes come one. The solenoid has a return valve but it?s just blocked and does not return to the master cylinder. Is it possible to use this type of solenoid as just a pure lockout and plugging the return valve?

Thanks

 

[Silvertip]

Re: lockout solenoid problems

What is probably happening is you are stopping going downhill which applies the brakes before the lockout solenoid is energized. To test the system, block the trailer wheels, then pull ahead slightly to remove brake pressure. Then shift to reverse and see if you can back up. If not -- there is obviously a problem.

 

[dingbat]

Re: lockout solenoid problems

I've never had much luck with a pure blocking solenoid.

Unless the actuator is fully extended when you put the vehicle in reverse chances are that you'll have pressure trapped in the lines causing a partial actuation of the braking system. Get yourself into a situation where you don?t always have the room to pull forward on a downward slope,( i.e. my driveway) you have problems.

The bleed type solenoid is not 100% fool proof either but a vast improvement over the blocking type if you have a lot of maneuvering to do.

 

[jkru]

Re: lockout solenoid problems

I also just found out that the new actuator I ordered, the guy accidently got me the drum brake one arrrggghh..

Anyways even backing up on a fairly level surface the lockout does not work and I cannot get down the boat launch.. Is there any alternative to these lockouts using surge brakes?

Thanks for the help!

 

[dingbat]

Re: lockout solenoid problems

The problem you're having is with the actuator.

Drum brakes are retracted by the springs and thus use a residual value to keep back pressure on the brake cylinders. Disc on the other hand are retracted via the ?vacuum? created by the actuator moving forward.

With the residual value left in place inside the drum coupler the vacuum necessary to retract the disk brakes isn't there and you?re effectively driving around with the brakes partially actuated all the time.

Get the right coupler on the trailer then worry about the solenoids being the right configuration for the situation.

 

[bruceb58]

Re: lockout solenoid problems

You could have kept your original coupler/master cylinder and just removed or disabled the residual valve.

 

[DABS]

Re: lockout solenoid problems

jkru, you are quite correct. If the return port is blocked it will not work. Some master cylinders have a plug that can be removed and replaced with a nipple for the return line. This looks like a peter paul solenoid. Once energized the piston blocks off the port going to the trailer and diverts it to the bypass, and back to the reservoir. If it's not able to do that, it leaves all the fluid trapped and the brakes will still drag.

 

[jkru]

Re: lockout solenoid problems

Thank you everyone!!

This is so helpful. What amazes me is that the manufacturer cant even give the level of details you are providing. I will get the correct Actuator and Solenoid and update you all. I replaced the lockout solenoid today just to try it out. Seems to work better. I will get the new master cylinder next week and put it in.

Thanks everyone!
Jkru

 

[Randybeall]

Re: lockout solenoid problems

Just a thought, many acuators have a hole to put a lock out pin into. Some states, like Colorado, do not like surge brakes and require that they be locked out on the highway. Some little problem about trailer brakes catching fire on a long down grade seems to bother the officals. Anyhow, check your hitch and see if it can be pinned out, that is handy when moving a trailer which you don't have the correct electrical connection for too.

 

[captharv]

Re: lockout solenoid problems

try:
championtrailers.com
They will help you as they are a trailer specialist.
The port which is blocked off. That requires drilling and tapping the master cylinder and installing a fitting.
the master cylinder for drums has a pressure retainer thingy as stated.
Remove the master and the hose from its rear. Then, thru the hose opening, ise an icepick or a scratch awl and hammer it thru the disk just inside of the hose connection. That will disable the pressure retainer.
Or, as long as you are buying a new master cylinder, order one with the anti-reverse valve already installed. May be a few more $$ but its the easiest way out. Then, bleed it and get the air out.
I am towing about the same weight you are. I have 4 wheel disks, radial tires and the 3 way anti-reverse valve. The rig tows so smooth that you can forget that you have 4 tons behind you. It also stops almost as fast as without the trailer.