Trailer brakes?

[Marvin willis]

New master cylinder installed and I have trailer brakes for the first time in four years. So glad this project is over. Someone locally has another trailer tongue for sale for $30. Considering buying it for a back up

 

[Paulie]

@Marvin willis , I look forward to your write-up. I just towed down to Florida and back and realized that I did not have any trailer brakes the whole trip. But like you said, with a 2500 you don't really notice it that much. Would you recommend just replacing the whole tongue assembly after knowing what you went through?

 

[Marvin willis]

No. If you think it's the tongue that's the problem compress it and loosen the bleeder valve. If you don't have any fluid squirt out unscrew the brake line from the reverse actuator to make sure it's not stopped up. If it's dripping out this your master cylinder is bad and easy to replace. Paid $60 with shipping. Heads up bleeding the brakes is fun

 

[Paulie]

Thanks! Could you possibly post a link to the master cylinder that you purchased?

 

[Marvin willis]

UFP Master Cylinder #34762 for UFP Disc Brakes https://www.amazon.com/dp/B006UH5V2Y/ref=cm_sw_r_cp_apip_6FDoxqRS6dIwn

 

[Paulie]

Excellent! Thanks!

 

[Marvin willis]

Ok. Here is my story on trailer brakes.... about four years ago one of my brakes were making noises so upon my investigation I realized the pads were worn and the pistons on the caliper were fully extended and wouldn't compress so I just pulled the calipers off. Since then the rotors rusted and all I had left of brake line was literally one foot at the tongue. So I decided to order new rotors, calipers with pads, a 20 ft, 8 ft, and 1 ft of rubber brake line ( no more rust) also 1 three way splitter for the brake lines. After everything came in I installed it I filled the master cylinder with fluid and opened the bleeder valves until fluid started to come out. After multiple attempts at bleeding the brakes I couldn't get any pressure so I pulled the tongue off to investigate further. After taking it all apart I realized lots of problems. The piston in the master cylinder was frozen. After I got that going there was a lot of salt corrosion in the master cylinder and everytime I thought I had it cleaned out and put it all together it made a wall of trash between the master cylinder and reverse actuator. I finally got it clear and pumping fluid but not enough pressure to compress the brakes. I did manage to take apart the reverse actuator. I realized if you unscrew it and and apply power to the wire you will see and little spring loaded magnet that pulls up. At least I was able to rule that out as a problem. So anyway I ordered a new master cylinder from Amazon and installed that and put the tongue back on. I was able to compress the tongue by hand to bleed the brakes until they got too tight. I hooked up the truck after that going fwd, back, repeat and finish the bleeding. That went on until I tore up my yard spinning the tires on my 2500 with the boat trailer hold its ground. I sure would have been easier to bolt up a solid tongue and never looked back. I did go with zinc and aluminum rotors and calipers so maybe the salt water won't eat them up this time. If anybody has any question just send me a message.

 

[dirksgoat]

@Marvin willis, make sure the Shock that is in that unit is still good. it controls how fast the piston for the "master cylinder" slides back to apply hydraulic pressure for the brakes. I used to install surge brakes on several models of trailers. The "solenoid" that uses 12 volts closes when vehicle is placed in reverse by truck wiring from the "reverse light" circuit. when its closed it does not allow the master cylinder piston slide back to apply pressure to brakes. Just locks it in that spot Hydraulically. Basically same way "line locks" work on drag cars to do burn outs....

I had to replace my entire break system, lines, rotors, calipers, whole front assembly. this is the Hydraulic Disc Brake Actuator Coupler i used. i ordered a whole kit which i can look up if needed.

https://www.pacifictrailers.com/collections/brakes-and-parts/products/ufp-a-75-brake-actuator-for-tandem-disc-brakes-7500lb-cap-bolt-on-47102

video how surge brakes work...

 

[Marvin willis]

I'm good to go now thanks though

 

[Paulie]

@Marvin willis , I am finally getting around to my brakes. When you slide the actuator assembly out of the tongue, is the flexible brake line supposed to be long enough to extend out and the unscrew from the assembly? Mine was too short and the ends don't spin freely from the hose itself so I have to twist the hell out of the flexible line to get it apart and back together.

 

[Marvin willis]

I disconnected the line before sliding the actuator out.

 

[Ronnie]

@Paulie , my 2010 mfi trailer is the same way, line not long enough. Did what you described and it took forever, hours not minutes. Would be worth the time to try and id a loose point in the line to borrow from so that you could detach the tongue , remove the actuator from it and spin the entire assembly off/on the line.

 

[Paulie]

Thanks guys. Does the replacement 24" flexible hose have free spinning ends or are they fixed on either end of the hose?

 

[dirksgoat]

Thanks guys. Does the replacement 24" flexible hose have free spinning ends or are they fixed on either end of the hose?

Did you buy a rebuild kit? reason why i ask is the reason why they put the 24" flexable line in the tongue is for the "swing" action of the tongue with the original metal lines.

as for free spinning, not sure what you mean. those trailers were not designed with a place for the flexible line to be rigid to anything. all you have to make sure is to use back up wrench that fittings are tight, and there it not any unnecessary twists in it.

the kit i bought uses a a flexible line like this in the kit, that runs the full length from the actuator on the trailer down the "STBD" side where it splits for both brakes.

https://www.pacifictrailers.com/products/ufp-db-35-complete-disc-brake-kit-w-a-75-actuator-reverse-solenoid-3500lb-axle

 

[DCB-270]

I got a 19 ft thermoplastic line from Amazon. It had the spinning ends that my factory line did not. It had a bunch of wind up.

 

[Paulie]

I figured it out. I didn't realize that the flexible line in the tongue needs to be detached from the metal fixed line that runs through the trailer frame and then you pull the whole assembly out with the flexible line still attached to the reverse solenoid. Thanks to all for you input.

 

[Jgorm]

I'm glad i read this. My brakes are f'd. There is rusty crap inside the mc, lots of it! With a strong vacuum i pull fluid, but the mc level doesn't go down the slightest. I'm planning on running with no brakes. I have a 3hr tow to the river then it will be 5 minute pulls to the ramp. If i add brakes, I'll go electric.

 

[Sbrown]

If i add brakes, I'll go electric.

Not a good idea on a boat trailer. If you want the best, go electric over hydraulic. Gets rid of the surge actuator and replaces it with an electric pump to activate you hydraulic brakes. Install an electric brake controller in your truck same as you would for electric brakes.