Trailer reversing brake problem ???
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From: moray on 4 Jan 2008 15:11 "Chris Whelan" <cawhelan(a)prejudicentlworld.com> wrote in message news:Fxvfj.21070$ov2.3924(a)newsfe5-win.ntli.net... > thelane wrote: > >>>Looks like an auto-reverse hitch, so either the brakes aren't adjusted >>>properly (usually they just don't work on the handbrake if the >>>adjustments >>>that far out), the shoes are seized so they're not releasing on reverse, >>>the shoes are fitted the wrong way around so you're in effect getting an >>>auto-forward, or the wrong shoes are fitted (highly unlikely, but not >>>impossible). >>>It could also be somebody has fitted a new hitch. >>> >>>Best option is to strip all the brake drums of and see what's going on. >>>If >>>it's more than a few years old, it's always wise to do to make sure >>>everything is still attached where it should be (linings tend to start >>>lifting of the shoes after a few years), and moving freely. >> >> So I am looking for a non existent catch or peg. >> >> If the handbrake was not effective, surely the brakes would not work >> forward or reverse ?? >> >> The hitch does not look particularly new, by the state of the grease >> around the handbrake lever >> >> Any good sites or links to show me the correct method of assy of the >> brakes ??? > > Any help? > > http://www.towitall.co.uk/trailer_spares/lockheed.htm > That's quite a good link. Best option is to strip all the brakes down, and check them. Remove wheel (it's best to lift the whole trailer up, and support it, as it makes final adjustment easier) Unwind the brake adjusters - usually rusted and can take a bit effort to move, but they're pretty robust items so don't worry about putting too much force on to get them to move. Take the drums of - will be a standard taper roller bearing, with castellated nut and split pin. Remove the brake shoe retaining spring - there's only one spring fitted to the trailing shoe (ie. the 'standard' looking shoe, which should be fitted at the rearmost side provided the brake actuator is at the bottom) Pull/lever the shoes over the actuator or adjuster, unhook the springs, and remove the shoes. Unwind the adjuster bolt right out, and remove all the bits of the adjuster (two cheese wedge bits, and a central wedge the adjuster screws into. Check the brake cable is free - pull the handbrake on, let it off, and check to see that you can pull the cable back out at the actuator by hand/with a pair of pliers. If you can't pull the cable out easily, then it's starting to seize and it's best to replace it. Also check for any cable fraying. Check that the actuator is free - it should move easily. If not, apply some oil to the pivot, and work it until it is free, then clean of any excess oil. Check that the brake shoe linings are still firmly attached - look for any signs of seperation around the edges, and try gently levering the linings away from the metal with a small screwdriver. If they're starting to lift, get new ones. The lining will eventually fall off, causing the wheel to lock up. Also check the auto-reverse shoe isn't seized - either clamp the inner section in a vice and pull the shoe in the direction of the springs, or try levering it with a suitable screwdriver. Check the outer part moves, and the springs pull it back in. Now that you've checked everything, take the adjuster wegdes, and clean them up. If they're rusty, clean out the housing as best you can with a screw driver/file/sharp edge to clean any corrosion off. But more importantly, give the sliding faces (ie the rear side, and where the center adjusting wedge contacts) of the wedges a rub on some sandpaper/wet and dry/emery cloth to polish them up, so they slide easily in the housing (this makes adjusting far easier). Also clean up the bolt. Assemble the adjuster back together using some copper grease on the sliding faces, and tighten the adjuster bolt to the point the wedges are as far in as they can be without there being any float/play in the central wedge (this saves winding forever trying to adjust them back-up once the drum is back on). Lubricate the actuator with some oil/grease, but make sure you wipe of any excess once you've worked it into the pivot. Refit the shoes (reverse of the above, but with a few more expletives). Make sure the hand brake cable is adjusted far enough off, that brake actuator isn't being held on (if you look at the actuator, when it's fully off, the lever rests against a stop). Fit the drum. Adjust shoes up until the adjuster locks up with moderate pressure using a spanner/ratchet, then back the adjuster off about quarter to half a turn until the drum can be spun freely by hand (some dragging is normal - expecially if you've fitted new shoes). To check the auto reverse is working at this point, with the adjuster wound on fully, try spinning the drum backwards (it might need a bit lever to initially go, but it should move) - it's best doing this after you've done the adjustment above, and remember how far you turned the adjuster. If you activate the auto-reverse by accident while adjusting, spinning the drum forwards should deactivate it. Fit the wheel. Repeat the above for each wheel. Cable adjustment can be a bit hit awkward. Adjust the individual cables until there's no slack in them (try pulling the cable end through the bar where they all meet - any slack will be obvious), and so the compensating bar is balanced. You may also have to adjust the main control rod if you can't get enough adjustment in the cables. Pull the handbrake on - it should only come up a few inches. Go round each wheel, and check they can't be turned forward. Then go round and try turning each wheel backwards -they should only turn partially before relocking. If they don't lock, give the handbrake another bit pull on (technically you shouldn't need to, but it's not always the case), and check the wheel is locked. Provided the wheels are all now locked, the adjustment is fine. If you can still spin any of the wheels, then re-adjust the shoes. Let the handbrake off, and check the wheels turn. Let the trailer back down onto it's wheels, and for a final check, pull the handbrake on, push the front of the trailer to one side until the wheels that are going backwards lock up, then push to the otherside so the other wheels lock up. Provided the brakes work in that way, the auto-reverse should word when coupled up. If it doesn't, then let some adjustment of the main brake rod from the coupling. And in case you're wondering how the hand brake overides the auto-reverse, the handbrake pulls the main brake rod further than the coupling can, so the brake shoes are pushed on past the auto-reverse. The auto-reverse shoes, the shoe can only move so far, and provided you push them on enough, they essentially act like a conventional brake shoe.
From: thelane on 6 Jan 2008 16:45 I am with you up until this point. >To check the auto reverse is working at this point, with the adjuster wound >on fully, try spinning the drum backwards (it might need a bit lever to >initially go, but it should move) - it's best doing this after you've done >the adjustment above, and remember how far you turned the adjuster. If you >activate the auto-reverse by accident while adjusting, spinning the drum >forwards should deactivate it. So what stops the brakes being applied when in reverse. As you say that the brakes come on when you spin the drum backwards. Surely I do not want the brakes to come on when reversing. Or am I being a bit too simple. I presume I can still drive it OK, fully loaded up hills and down hills forward, but not do any reversing until I can get it sorted.
From: Tim.. on 6 Jan 2008 17:00 "thelane" <thelane(a)yahoo.co.uk> wrote in message news:2ki2o3512et3686dipfdshe0k0obv4ji0l(a)4ax.com... >I am with you up until this point. > >>To check the auto reverse is working at this point, with the adjuster >>wound >>on fully, try spinning the drum backwards (it might need a bit lever to >>initially go, but it should move) - it's best doing this after you've done >>the adjustment above, and remember how far you turned the adjuster. If you >>activate the auto-reverse by accident while adjusting, spinning the drum >>forwards should deactivate it. > > So what stops the brakes being applied when in reverse. > > As you say that the brakes come on when you spin the drum backwards. > Surely I do not want the brakes to come on when reversing. > > Or am I being a bit too simple. > > I presume I can still drive it OK, fully loaded up hills and down > hills forward, but not do any reversing until I can get it sorted. You can carry on reversing it if you like, but you'll be needing a new clutch in short order! Tim..
From: moray on 6 Jan 2008 17:09 "thelane" <thelane(a)yahoo.co.uk> wrote in message news:2ki2o3512et3686dipfdshe0k0obv4ji0l(a)4ax.com... >I am with you up until this point. > >>To check the auto reverse is working at this point, with the adjuster >>wound >>on fully, try spinning the drum backwards (it might need a bit lever to >>initially go, but it should move) - it's best doing this after you've done >>the adjustment above, and remember how far you turned the adjuster. If you >>activate the auto-reverse by accident while adjusting, spinning the drum >>forwards should deactivate it. > > So what stops the brakes being applied when in reverse. > > As you say that the brakes come on when you spin the drum backwards. > Surely I do not want the brakes to come on when reversing. No. The handbrake pulls the brake cables further than what the coupling alone can, so the auto-reverse function of the shoes is overidden. > Or am I being a bit too simple. > > I presume I can still drive it OK, fully loaded up hills and down > hills forward, but not do any reversing until I can get it sorted. Depends what's causing the problem. It may continue to work fine, but it could also be the sign of something bad about to happen...
From: Duncan Wood on 6 Jan 2008 17:11
On Sun, 06 Jan 2008 22:09:17 -0000, moray <mtb_hyphen_rules(a)hotmail.co.uk> wrote: > > "thelane" <thelane(a)yahoo.co.uk> wrote in message > news:2ki2o3512et3686dipfdshe0k0obv4ji0l(a)4ax.com... >> I am with you up until this point. >> >>> To check the auto reverse is working at this point, with the adjuster >>> wound >>> on fully, try spinning the drum backwards (it might need a bit lever to >>> initially go, but it should move) - it's best doing this after you've >>> done >>> the adjustment above, and remember how far you turned the adjuster. If >>> you >>> activate the auto-reverse by accident while adjusting, spinning the >>> drum >>> forwards should deactivate it. >> >> So what stops the brakes being applied when in reverse. >> >> As you say that the brakes come on when you spin the drum backwards. >> Surely I do not want the brakes to come on when reversing. > > No. The handbrake pulls the brake cables further than what the coupling > alone can, so the auto-reverse function of the shoes is overidden. > >> Or am I being a bit too simple. >> >> I presume I can still drive it OK, fully loaded up hills and down >> hills forward, but not do any reversing until I can get it sorted. > > Depends what's causing the problem. > It may continue to work fine, but it could also be the sign of something > bad > about to happen... > > And if you've ever driven a trailer with brakes that only work on one side you don't ever want to do it again. |