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Bob1340 · 05-11-2016, 10:00 AM

I have no idea how I did it but I did! I changed my wheel bearings and although I was very careful and had everything spotlessly clean my brakes worked like crap afterwards. Only one wheel would lock up and even after adjusting them all they still work like crud.
So I ordered new brakes off eTrailer and got the self adjusting units. Not bad price actually.

Any advice on how to prepare my hub/drums for the new brakes? I intent to wipe them out with brake cleaner again and them sand the friction surfaces with 100 grit emery cloth, both the pad and magnet surfaces of course.

Any other advice?

lynnmor · 05-11-2016, 10:07 AM

Keep that 100 grit off the magnet and drum armature surfaces, it is to have a high finish. If it is ugly, get them faced (few people can do it right), or replace the drums.

Bob1340 · 05-11-2016, 10:27 AM

Quote:

Originally Posted by lynnmor

Keep that 100 grit off the magnet and drum armature surfaces, it is to have a high finish. If it is ugly, get them faced (few people can do it right), or replace the drums.

They look good. Not ugly. So no sanding. Thanks for the advice.

After thinking about it for a while I think I know where I went wrong. After I installed the bearings and put the seal in I wiped up the small amount of excess grease and mopped up with brake cleaner on a clean rag. But I bet a $10 bill to a doughnut there was some errant grease I wiped into the recessed lug nut bosses. That getting on the magnet surface is gonna ruin it.

lynnmor · 05-11-2016, 10:46 AM

Since you cleaned the drums, you will find the brakes won't work well till they again build up a film. Look up the burnishing process for new brakes. My guess is that you wasted your money, just wait till you see how long those new brakes take to reach full stopping power. Also, I don't like self adjusting because the drums often have too much run out for them to work properly. For someone like you that doesn't mind doing some work, a few minutes a year shouldn't be an issue.

Bob1340 · 05-11-2016, 12:01 PM

Quote:

Originally Posted by lynnmor

Since you cleaned the drums, you will find the brakes won't work well till they again build up a film. Look up the burnishing process for new brakes. My guess is that you wasted your money, just wait till you see how long those new brakes take to reach full stopping power. Also, I don't like self adjusting because the drums often have too much run out for them to work properly. For someone like you that doesn't mind doing some work, a few minutes a year shouldn't be an issue.

I took one hub off this morning. I was correct with grease in the lug nut holes being the culprit. I could just replace the magnets as they are suspect of being impregnated with grease, but that runs $23-$27 a pop and the whole new backing plate is only $48 bucks. My pads are getting down to 40%-50% maybe worse and my adjusters are in bad shape as well, I had a heck of a times getting them to move. I fully understand the break in procedure for new brakes or "cleaned" drums/rotors. I've never done it on trailer brakes but I'd guess it to be fairly simple using the brake controller.

I want hydraulic disc.

Bob1340 · 05-11-2016, 12:07 PM

Quote:

Originally Posted by lynnmor

Since you cleaned the drums, you will find the brakes won't work well till they again build up a film. Look up the burnishing process for new brakes.

BTW, I was going though the process of brake/rest/brake/rest etc and my rear left wheel was fine after 10-15 hits of the controller. The other 3 seemed to do nothing. If I hit the controller hard enough my left rear was locking up. Hence my suspicion of contamination. I wager when I pull the other 3 hubs 2 will have grease on the magnet and that left rear will be clean.

RSchleder · 05-11-2016, 08:34 PM

If there is grease on the magnet, can it, and the surface it contacts on the hub, simply be cleaned up with brake cleaner or ? and reassembled? If not, what is the correct process to fix this situation?

lynnmor · 05-12-2016, 05:34 AM

Quote:

Originally Posted by RSchleder

If there is grease on the magnet, can it, and the surface it contacts on the hub, simply be cleaned up with brake cleaner or ? and reassembled? If not, what is the correct process to fix this situation?

You can clean everything with brake cleaner. If the brake shoes have been soaked with grease, it might not be possible to get it out and the shoes may need to be replaced. There is to be a small amount of grease where the shoes contact the backing plate and on the anchor pin. That grease needs to be applied after a cleaning. I use a grease special made for that purpose.

Bob1340 · 05-12-2016, 07:28 AM

Quote:

Originally Posted by RSchleder

If there is grease on the magnet, can it, and the surface it contacts on the hub, simply be cleaned up with brake cleaner or ? and reassembled? If not, what is the correct process to fix this situation?

The problem is the grease in beds itself into the brake material and as heat builds up it shows it's ugly face. Hard to get out. Mine were pretty well worn so I am just going new. The main thing (which this old dog has learned) is to be very careful with your greasy hands etc when handling the drums etc when re-packing your bearings.