Brakes not releasing

[the76kid]

I have a 2000 trailer for my 2000 Ranger 520. Recently I replaced the entire actuator assembly. After bleeding the system the brakes worked fine, until my last trip when the brakes will not completely release. They are dragging enough to get quite hot but when I had them checked by my mechanic they were not tight in his garage. The actuator is working correctly. He suggested that maybe the flexible brake lines had broken down on the inside and were not allowing the pressure to completely go off after braking. Any suggestions if this makes sense and if so where to get the parts I need to fix it.

[DABS]

Dragging brakes are usually caused by a blockage of some sort. A new actuator should rule out anything up front but your mechanic's suggestion to replace the soft lines is spot on. On the outside they may look new but the important part is the inside lining. It is made like a toilet paper roll and any part of it that breaks can cause it to ball up and create a blockage not unlike a beaver dam. The actuator has plenty of power to bypass it with fluid but there is nothing to allow a relief on the return passage. The result is, for a while at least, pressure on the brakes until the fluid can seep back past the blockage. Try opening a bleeder to see if this releases the caliper. If it does, the caliper is doing what it is supposed to do. If not, the caliper is at fault.

[western angler]

I have a 2000 trailer for my 2000 Ranger 520. Recently I replaced the entire actuator assembly. After bleeding the system the brakes worked fine, until my last trip when the brakes will not completely release. They are dragging enough to get quite hot but when I had them checked by my mechanic they were not tight in his garage. The actuator is working correctly. He suggested that maybe the flexible brake lines had broken down on the inside and were not allowing the pressure to completely go off after braking. Any suggestions if this makes sense and if so where to get the parts I need to fix it.

Bleed them again. You didn't convert
drum to disc's and not change the master cylinder did you? You can't use the same master cylinder. Or did you buy one for drum brakes and you have discs?

[DABS]

they are the same master cylinder western angler. Doesn't matter if it is drum or disc.

[billnorman1]

Brakes get hot, that's how they work. If they melt the tire obviously they are too hot. If you think they are too hot, as DABS recommended, crack a bleeder, if fluid spurts out you have a hydraulic issue. Don't have it attached to the truck facing downhill. Speaking of downhill, your tongue is equal or higher than the trailer frame, isn't it?

[OldTimer57]

Nope, NOT the same master cylinder. If you go to order an A60, you have to specify which type of brakes you have. World of difference in operating pressure requirements. Drums have a self-actuating characteristic caused by the rotational force of the drum actually pulling one shoe into firmer contact while pushing the opposite shoe away. Disks don't have this. Discs require higher pressure, which means more fluid volume into a much bigger piston/cylinder chamber.

I'd bet the OP's problem is the dust boots and seals are old and cracked, letting moisture in to the piston/cylinder gap and causing rust which will bind the caliper and can totally stick it engaged, or simply greatly delay the caliper's release.

First diagnostic check is to pressurize the system using the screw driver in the actuator hole trick. With both wheels jacked up. If one (or both) won't spin freely after levering the master cylinder pushrod, you can try cracking open the bleed screw on the one (or both) that is/are stuck. If that releases the brake, there's a hydraulic blockage, most commonly in the master cylinder. To confirm the master cylinder is acting up, again lever the master cylinder to engage the brakes, thenput vehicle in reverse with trailer connected. If wheels are now free, the master cylinder is bad, since the reverse solenoid just released the built-up pressure showing you it is not in the brake lines themselves. If the bleeder doesn't fix the problem, time for either a caliper rebuild or a new caliper.

[DABS]

The reason they as if you have disc brakes or drums relates to the solenoid, not the master cylinder. Examine the drum master and you will see a plug on the bottom that is replaced with a mini-barb fitting for the return line to the solenoid. Also, the drum master comes with an inverted flair fitting to accommodate the brake line. Remove the fitting and screw in the solenoid and you have a disc brake master cylinder.

[the76kid]

Thanks for all the replies guys. I may still have a brake fluid, actuator issue, but the bigger problem was found after removing the wheel and checking the caliper itself. Make a long story short, I have 2 new calipers and all new brake pads coming from Ranger. Once installed we will see what happens.

[CigarBasser]

How’d your project turn out? Having some issues and I believe my system is contaminated and looking to have the system fully purged, cleaned, repaired/replaced as needed.

[OldTimer57]

As I and several other said, the disc / drum master cylinders are NOT the same. And the solenoid is not the only difference. In a drum brake, you need less pressure because of the self-actuating that happens as drum rotation pulls one of the shoes into tighter contact. However, you need a lot of fluid volume, because the shoes are retracted by springs, and you have to move them quite a ways to get them to contact the drums. The M/C has a bigger bore to pump more fluid. However, a bigger piston means lower PSI since the same force from the trailer surging into the tow vehicle will be spread over a larger area with a bigger M/C. Discs require less fluid since they are always barely contacting the rotor as there is no spring to retract them. They also need much higher pressure since the disc brakes do not "self actuate" at all. This means a smaller diameter master cylinder bore so that the surge force is applied to a smaller area and produces the needed higher pressure.

If you put a disc M/C on drum brakes, you might end up with no brakes whatsoever, particularly as the shoes wear, because the M/C doesn't pump enough fluid to push the shoes out to contact the drum. And you will definitely end up with jerky brakes if they do work, because the pressure will be much too high and cause the trailer to chatter back and forth. If you use a drum M/C on disc brakes you will get ineffectual braking because the pressure is too low. You have to get the right M/C for the type of brakes if you want the brakes to work as designed.

[CatFan]

As I and several other said, the disc / drum master cylinders are NOT the same. And the solenoid is not the only difference. In a drum brake, you need less pressure because of the self-actuating that happens as drum rotation pulls one of the shoes into tighter contact. However, you need a lot of fluid volume, because the shoes are retracted by springs, and you have to move them quite a ways to get them to contact the drums. The M/C has a bigger bore to pump more fluid. However, a bigger piston means lower PSI since the same force from the trailer surging into the tow vehicle will be spread over a larger area with a bigger M/C. Discs require less fluid since they are always barely contacting the rotor as there is no spring to retract them. They also need much higher pressure since the disc brakes do not "self actuate" at all. This means a smaller diameter master cylinder bore so that the surge force is applied to a smaller area and produces the needed higher pressure.

If you put a disc M/C on drum brakes, you might end up with no brakes whatsoever, particularly as the shoes wear, because the M/C doesn't pump enough fluid to push the shoes out to contact the drum. And you will definitely end up with jerky brakes if they do work, because the pressure will be much too high and cause the trailer to chatter back and forth. If you use a drum M/C on disc brakes you will get ineffectual braking because the pressure is too low. You have to get the right M/C for the type of brakes if you want the brakes to work as designed.

You do realize you are arguing with the company that makes these brakes, right? I suspect they know if the MCs are the same or different. DABS works for UFP/Dexter.

[fishnfireman]

Had a DPS officer tell me he knew the traffic laws when I tried to tell him he was wrong... He found out later he was..

[OldTimer57]

WHERE do you think I got my info? I replaced my actuator (A60) back in January. They ASKED me which one I needed.

[CatFan]

WHERE do you think I got my info? I replaced my actuator (A60) back in January. They ASKED me which one I needed.

The master cylinders are the same. You can convert from drum to disk by punching a hole in a plug so fluid can flow back. The difference is only that the disc brake setup allows fluid to flow back to make up for the lack of springs to move the pads off the rotors. Same thing Dennis told you above. Call them and ask. You'll end up talking to Dennis.

[OldTimer57]

Go to the UFP actuator parts listing anywhere. The disc M/C and drum M/C are DIFFERENT part numbers. And neither includes the solenoid, which is extra. When I ordered mine back in Jan, I called UFP. Told him the boat make (Bass Cat) and the actuator style (A-60). He asked me two questions: (1) disc or drum; (2) 2 or 4 calipers. Told me specifically that they had to match. That's all I can go by. Certainly drums need way more fluid to actuate thanks to the retraction springs. My actuator will compress about 1/3 of the way, max. So there is volume left. Whether it is enough or not I can't say as I only have the old one (disc) to measure with a caliper. I'm simply repeating exactly what I was told when I contacted UFP via phone. Do not know who it was.

Edit:

Been working on cars all my life. In thinking about this, the wheel cylinder is pretty small compared to the caliper pistons. The caliper pistons don't move very far, but since the bore is much larger, might well be that the fluid requirement is similar, although obviously drums require less activation force compared to much more force needed for discs. Obviously the same quantity of fluid will produce significantly different stroke travel when the pistons are so wildly different in size. Bigger piston = much less travel but much higher compression force, vice-versa for the drums. So maybe the person I talked to was correct about different part numbers, but not so correct on the reason...