Trailer brake stopping- Is this good enough?

Discussion in 'Tires / Brakes / Bearings / Axles' started by davekro, Sep 20, 2019.

  1. davekro

    davekro Active Member

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    Ok, I got my Tekonsha P3 wired into the TV with much work, but happily found the controller is extremely user friendly.
    First test run to set voltage for braking: even at max 14 volt signal -AND- B0, 1, 2, or 3, trailer brakes would not lock up just using the P3 manual braking lever. From 25 mph, it took a long time to even slow the rig a little.
    •Back in driveway I manually adjusted the brake shoes out so the tire/ wheel assy spun ≈ 3.5 rotations on each side.

    Second test run to set voltage for braking
    : even at max 14 volt signal -AND- B0, 1, 2, or 3, trailer brakes would not lock up just using the P3 manual braking lever. From 25 mph, not much improvement.

    •Back in driveway I manually adjusted the brake shoes out 3 clicks on each side. I did not take the time to raise the axle and spin wheel. Drums were hot from my testing, so am hesitant to move drums out more clicks.

    Third test run to set voltage for braking: even at max 14 volt signal -AND- B0, 1, 2, or 3, trailer brakes would not lock up just using the P3 manual braking lever. From 25 mph, some improvement. I could hear the 'brake shoe engaging sound' and the whole rig did get brought to a stop over a pretty long distance. FOr reference, I adjusted the brake shoes out (up on adjuster) ≈ 18 and 24 'clicks' on respective sides. I thought that was already a huge adjustment! I am leaving it here for our trip today into the gold country foothills from the valley. (I just thought to bring the brake adjusting tool... just in case).

    Have people found on 20 year old trailers wear out their drums past max operating dia specs? Actually, I thought that max dia spec was for not making drum wall thickness to thin, not because the shoes would not operate efficiently 'out that far', but I don't know. I'm told this Pup one only did ≈ 2-3 trips per year and mostly to places 1-2 hours away and mostly flat driving, so that hints that drums are not worn out.

    I did not pull the hub/drum assy's to inspect. I will after this trip. Might it be that the surface between the drum and magnet may be compromised from dirt or rust?? That might clean off after some actual driving with brakes working on the trip? I will do the 25 mph lock up test a time or two during the trip.

    Am I overly concerned that the trailer brakes work too hard and over heat the trailer brakes? On our last trip I did feel the hubs for bearing heat. It was a 95º day and they felt about ambient temp, so bearings seem good. What is normal to expect for trailer brakes to heat up: the hub? the rim near the hub? Should the drums dissipate all the heat they generate or will the hubs (and rims?) warm up also?

    Off to finish actual packing now (Yes honey, I'm coming ;o).
     
    Last edited: Sep 20, 2019
  2. Raycfe

    Raycfe Waterford Ct.

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    The brakes will stop the trailer, but usually never lock up. Me think you are thinking too much!
     
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  3. Sjm9911

    Sjm9911 Well-Known Member

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    Yes , depending on the TV and its weight a most 3000 lb pop up isnt going to slow it down that much. If my breaks engaged on the pup, ( i could here and feel it ) i was good. My TV was a full size pick up. Now, i got a new TT and im going through the same thing as you, is it enough breaking power or too much. Set it untill it grabs and done.
     
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  4. McFlyfi

    McFlyfi Active Member

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    Did the PO use the brakes at all?
    You are unlikely to get to lock up at all.
    In my experience, unused or new brakes take time to "bed in".
    I've installed 2 sets brakes on 2 different trailer. The first one, the PO did not have a brake controller, and did not use the brakes. It took a while for the brakes to become effective. When I installed my first set of brakes, the local trailer guru told me to go to a parking lot, and heat up the brakes by repeatedly going from 20 mph to zero using the manual override.
    Gradually the performance improved in all three cases- one set of unused brakes, and two sets of new brakes.
    I suspect that when you return from your trip, the performance will be noticeably better.
     
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  5. davekro

    davekro Active Member

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    Great info from your experience. I brought a laser temp reader, so if the drums heat the hubs of rims at all, l'll back off the max voltage setting. Good to know just hearing and feeling the trailer brakes a bit is good enough. Thinking about it, if that much breaking was applied to just the trailer (not trying to slow the TV too), it would likely do that fine.
    Thanks again... we're on the road for adventure #2. :)
     
  6. xxxapache

    xxxapache Well-Known Member

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    I agree that a small trailers brakes can't be expected to stop the whole rig. You should feel drag like a parachute deployed behind you.

    With that said, I wouldn't click on the star wheel without jacking it up and spinning the tire.
     
  7. Grandpa Don

    Grandpa Don Active Member

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    Okay, I'll pass along my 2 cent. I added brakes to my Viking 1906. I went through the same thing with trying to get them to lock up. I was at 14 Volts. Not really sure what I did to fix it. I adjusted the Star in and out several times. Then I did the test on soft dirt. And they locked up big time. I did find that I had a bad vehicle to pup ground. I fixed that and it help a lot. Then I could lock them up at 6 volts in the dirt. The brakes were new, so I figured that they needed some break-in time. I just completed a 300 mile trip with the pup and I had to adjust the voltage down to about 3.5 to prevent over braking.

    So, make sure you have a good ground from the TV to the Pup. And give it some time to settle in. I'm sure they will get better in time and you will have to adjust the voltage down. Don't leave it at 14 volts. Test them in the dirt, not asphalt. By doing it in the dirt you will be able to tell is one locks up and the other does not. That's how I balanced mine. Also, do you have a break-away switch installed? I get the idea that you are in California. You will need a break-away switch installed. I have the same controller as you and a BW switch. The more I used my Pup, the better the brakes got and I had to readjust the voltage each time I went out. I was concerned at first, but am very pleased with them now.
     
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  8. Sjm9911

    Sjm9911 Well-Known Member

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    Lol, just got to the campground with the new TT. The brak controle has a low power signal. Not good.
     
  9. Grandpa Don

    Grandpa Don Active Member

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    I think you have a bad connection in the brake line somewhere. The brake wire should be Blue in color. Trace it back as far as you can to the 7-wire plug. And again, make sure you have a good ground.
     
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  10. Sjm9911

    Sjm9911 Well-Known Member

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    I have to check it out. Unfortunately my tv was pre wired, i need to check the conection at the fitting on the rear first, this way i can tell if its the tv or the camper. I will need help, new posts coming soon!
     
  11. Grandpa Don

    Grandpa Don Active Member

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    Also, it's not a good idea to adjust the Star wheel with out jacking up the trailer and getting the wheel off the ground. You are really just guessing where the shoes are by doing it that way. You could overheat and damage the drums. The proper way to do it is listed in the instruction of the Controller. Basically, jack up the wheel clear of the ground. Turn the Star until you feel or hear some drag on the drum. Then back off a turn or so. It's okay to hear a little dragging on the drum because the shoes can move around in there a bit. Just not too much. Set your voltage to some lower setting, say about 5 Volts or so, and forget it for now. Give them time to break in. Say 2 or 3 hundred miles. Then go in and check the adjustment again.

    And again, I think you have a wiring problem somewhere. There should be two wires going to your brake magnets (hubs). One is the control voltage (Blue), and the other is just frame ground. It is a really simple circuit, just two wires. Find them and trace them to find the short. Both wires from the magnet are most likely white.
     
  12. davekro

    davekro Active Member

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    First trip w/ P3 Brake controller installed report:
    Dexter 2200 axle w/ 7x1.25 brakes.
    I didn't know how much drag to set the shoes at when I had the wheels off the ground, so I set where, w/ wheel on, wheel spun ≈ 3.5 turns, before realizing they should not lock up (on pavement), I then tightened them up (on ground) two clicks, then we left town.
    On Friday one hour out of town, while still on the flats I checked the temps with a laser thermometer.
    Psgr side: hub 143º, drum 154º
    Drvr side: hub 127º, drum 140º

    On way home Sunday 30 mins after down hills: (ambient temp 89º)
    Psgr side: hub 200º, drum 217º *
    Drvr side: hub 130º, drum 128º
    (* I crawled under and adjusted psgr side drums looser 2-3 clicks)

    In driveway at home (all flat from last reading)

    Psgr side: hub 166º, drum 173º
    Drvr side: hub 122º, drum 118º

    I'm not sure if the hotter side is overworking or the cooler side is under-working. On the previous trip w/o brake controller & brakes with an ambient temp of 95º, the hub temps were at 95º. So my questions are:
    1) If it's OK for the brake drums to heat the hubs above ambient, by how much is normal/ expected?
    2) When I lift the wheels to readjust the shoes manually, how much drag should I allow? Now, thinking back to eons ago when I last installed new brake 'shoes', I believe I adjusted out until I could not turn the drum, then backed off until I could turn drum by hand, but certainly not loose enough to 'spin freely'. (I wish I had remembered this when I made the off ground adjustment on Friday before the trip... Doooh! )

    I like the 'in dirt' lock up testing for balance! Once I get them both to 'dirt lock up', I can use hub & drum temps to further verify balance.

    Thank you all for the great tips!
     
  13. Grandpa Don

    Grandpa Don Active Member

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    I think you might be over thinking this a bit. My brake controller say to raise the wheel off the ground and adjust until you start to hear some dragging. Then back off just a turn or so until no more dragging noise. Then leave it alone for some mileage, maybe a hundred or so. I will then go into the dirt and see how much voltage it takes to lock them up when applying the brakes manually. When I did this, one side was locking up in the soft dirt at about 6 volts. I then adjusted the other side so that they both would brake evenly. Then I backed the voltage down to around 3.5 or 4 and leave it. I've never checked the temperature at the hubs. I figure if they aren't smoking, they much be okay. LOL.

    Again, if your brakes are new, you may have to adjust them several times after they seat-in.
     
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  14. davekro

    davekro Active Member

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    GP Don,
    When I get time, I'll set it to 6 volts and go find some dirt test area. About what speed did you get to when you applied the trailer brake manually? I like your method of adjusting the non locking wheel to the locking one (at 6 volts), then reducing the voltage. Do you operate at zero Boost level I assume?
    Thanks
     
  15. Grandpa Don

    Grandpa Don Active Member

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    The speed wasn't important. I just moved ahead 20 feet and manually applied the brakes. Then got out of the truck and went back to check each wheel track. The trailer brakes are not suppose to stop the truck. Only assist in stopping by taking some of the inertia off the camper. Just follow the instructions in the Tekonsha P3 controller installation sheet, balance them in the dirt, and then forget them for a while. Initially set the control voltage to where you just feel a little resistance when you manually apply them at speed. The voltage you need to use will vary with time as the brakes seat to the drum. Especially if they are newly installed. I make it a habit to check my trailer brake voltage every time I take the camper out. I do this not only to make any adjustments they may need, but also to make darn sure they are still working. I think I learned that from my flying days. When I would start to taxi I would let the aircraft roll forward about 20 feet and then apply the brakes. That checks the balance and make sure they are working.
     
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