Having a problem with wheel overheating. Single axle 17ft van. Is always one side only being the left. Have checked everything, bearings, brake shoes, magnets, adjustment to no avail. Last use increased setting as per directions & ended up with Lh side wheel at 195deg, rh side at 35 deg. Starting to suspect increased voltage to the Lh side. My question is how to check voltage to each wheel when motion is required to activate controller, or so have been told. Controller is a Primus IQ.
There is an old expression that says you can't get something for nothing, and that is true with voltage.
So, given that you start with 12 volts, that is all you can get at the brake. However the controllers put out much less than that under normal circumstances.
In this instance can you narrow down the hottest part of the assmbley? Actual hub/bearings vs perimeter of drum.
You say that the LH gets hot. Could it be that that side is doing all the work while the RH side is the faulty one? i.e. not getting enough current to activate the brake on that side properly.
Or that the LH side is working normally when operated but then not releasing fully when pedal is eased.
What is the drag like when jacked up and turning the wheel by hand? They should be equal.
You may need to disconnect from vehicle, remove the drums, then isolate the shoe wiring from the loom and do some current measurements using a portable battery set-up to observe the shoe action. Could be an auto-electrician required for this.
Presumably you are measuring at the hubs. 195 degrees is very hot. If you drive and minimise applying the brakes, does it still get hot?
If it does, then I would suspect the brake drum is binding, perhaps being out of round. In that case you would probably feel it as a jerking motion when braking as well. When jacked up you would hear and feel it as the wheel is rotated. Bearing adjustment could also increase temperature.
You said "Last use increased setting as per directions". Do you mean you tightened the adjuster or loosened it (increasing the clearance). Maybe a description of what you do when adjusting, and how you drove before measuring the temperature.
Good point about increased voltage, never occurred to me. Only measure the brake drum so not sure which hottest although bearings always ok so thinking its brake related.did have drag come on lots tighter on lh when away up north last year . Might need some further investigation I think. Lh does seem to be tighter after driving though. so wondering if the problem is its not coming off or somehow adjusting itself. Really need to operate brakes while stationary to check operation but was told my controller only operates while in motion, so not sure how to do that.maybe a different controller? Further checks required but open to any other suggestions ie different controller?
Measuring brake drum in same place each time. Drums not very old & dont feel out of round. Still gets hot regardless. Did reduce severity of setting & did cool down substantially but only the lh side. More check needed I think
If you progressively swap components over from one side to the other, you should eventually find the culprit. Maybe swap the brake drums first then do a drive and check temps. Then do the same thing with bearings,
then brake shoes, then brake magnets, etc etc.
I would test the tempature difference between the actual hub and brake drum.
On a harvester I used to check temp on all bearings and if a difference between each end of shaft it was due to a bearing not as smooth running as should be. I couldn't see any difference but could feel slight rumble. I always check new ones before installing as some are faulty from manufacture, not often but does happen, usually with difficult to replace situation, Murphy's law.
Brake drums & hubs not separate so cant just do one of them. Thinking need to confirm lh brakes not staying on first & possibly try controller that works without being moving to confirm working ok or not. Thinking more investigation needed.
I had at one time a similar issue and ended up replacing in the entire backing plates which come completely assembled with shoes and magnets, the lot.
I just got sick of chasing my tail and the new assemblies are not that expensive.
When I did that it solved the issue.
The shoes on mine were getting down a bit at the time so at some point I was going to have to reline the brakes any way.
Sometimes you just have to bite the bullet and go the whole hog.
Errol , Try recentring the backing plate with the shoes adjusted up tight in the drum. just loosen the backing plate on the axle so it moves easily. adjust the brake shoes up tight while rotating the drum to centralise the the shoes . then retighten the backing plate bolts . now readjust shoes to clear the drum. When I adjust shoes so they are all even on all wheels I pull the breakaway pin to allow the magnets to grab the drum, then you should be able to rotate the wheel each way forward and reverse before the brakes grab on . I adjust the shoes to achieve back and forward rotation of 150 mm of the tyre on the ground . making sure the shoes are not dragging when the breakaway pin in put back in and brakes are off .
