2008 MFI Trailer question

[michaeljbenner]

Hello all!

My next project on my new-to-me 2008 AR210 is to get the trailer brakes up and running again.

I realized a couple of weeks ago that the steel line (the one that transfers fluid between the two calipers) was broken. Upon taking it all apart, it must have been for some time because the port caliper was filled with rusty water and was all seized up.

This appears to be an extremely poor design, with the fluid transfer line being hard-piped directly into the two calipers. With no rubber pigtails, any amount of flex will stress and eventually break that line.

Here is a pic of the (unbroken) starboard line, and the one of the broken steel line I am talking about:



Which brings me to my question: Can I drill into the axle beam to mount brackets to keep rubber hoses in place? Obviously on a car or truck this would be a no-no, as the axles are filled with fluid...but I don't see what the harm would be, as long as I sealed the fastener with silicone.

Here are the brackets I bought:

And the hoses:



Thoughts?

 

[suke]

I wouldn't drill when zip ties can work just as good. I did however drill into the frame rails for cable mounts. I used all rubber from the actuator to the calipers. Works great! I redid my whole braking system on my 2009 MFI trailer over last winter(actuator, hubs/rotors, bearings, brake lines, calipers/pads). It wasn't cheap, but it was nice having a whole new system. Mine was also completely rusted, but it didn't even have brake pads in there, so even if it worked.....it sure wouldn't have done much. LOL!

 

[Benoit]

I don’t think you need rubber hoses because there is no movement between calipers. You need a rubber hose from distribution block to frame. Also use grommets where the line goes thru the frame. The tough part is up by the swing tongue. Inside the starboard rail you have to go thru a small hole. I wrapped the line in shrink tube. Hope this helps

 

[dgfreeze]

Above advice is sound, I wouldn’t recommend drilling the axle beam. Not that it would be terribly detrimental, but it’s just asking for problems. We (my job) work on trailers every day, and when we deal with that kind of thing, we normally tack weld the bracket to the axle beam, or simply zip tie it. That aside, if you’re thinking about just using the rubber hose as a short repair, I’d recommend against it. It would be 100X better to replace the whole line going across...?? Trying to wrap my mind around exactly what your game plan is...

 

[michaeljbenner]

Above advice is sound, I wouldn’t recommend drilling the axle beam. Not that it would be terribly detrimental, but it’s just asking for problems. We (my job) work on trailers every day, and when we deal with that kind of thing, we normally tack weld the bracket to the axle beam, or simply zip tie it. That aside, if you’re thinking about just using the rubber hose as a short repair, I’d recommend against it. It would be 100X better to replace the whole line going across...?? Trying to wrap my mind around exactly what your game plan is...

My plan is to run the rubber hoses from the caliper to the brackets (either attached to the frame or the axle), and then a hard line between the two brackets. I will use stainless steel hose clamps to attach the hard line to the axle.

 

[dgfreeze]

Ok, if I’m seeing your system correctly, you should only need one rubber hose, which will go from the frame down to the caliper. The axle moves independently from the frame, thus requiring a rubber hose. Don’t use rubber anywhere it’s not required, because a rubber hose swells slightly under pressure during braking, which adversely affects braking power. Use hard line from caliper to caliper along the axle beam. Shouldn’t need to mount any brackets on the axle with your system, just zip ties or as you said, hose clamps to hold the hard line in place. All that said, if you’re changing the way it’s run, and going with a T-fitting on the axle, and a hard line from the T-fitting to each caliper, then you have to mount the fitting to the axle. Also, If you’re in freshwater, aluminized brake line is fine, but if you’re ever in saltwater, I’d strongly recommend stainless. Might be worth it either way.