Drum brakes binding after replacing wheel cylinder

[poconojoe]

2003 Karavan trailer with single axle drum surge brakes. Boat is 2003 Bayliner 185.
Replaced a frozen wheel cylinder. Wheel moved freely before the "repair". As I put the drum back on, there was a lot of drag on the brakes. The adjuster is turned all the way down and the brakes are too tight for my liking. Took it for a ride and the wheel was much hotter than the other one as I suspected it would be. The rubber boot on the end of the dusk cap is now missing too. Don't know if that is related to heat build up.
I don't get it. If the brake shoes are completely seated against that post on top and the adjuster is all the way in, then how come the shoes are so tight?
Thanks, Joe

 

[Silvertip]

Incorrect assembly, incorrect wheel cylinder, or incorrect shoes.

 

[Scott Danforth]

did the wheel cylinder pistons come out and get cocked in its bore? sometimes happens when replaicing a wheel cylinder, if the shoes are not adjusted properly. I generally replace the whole backing blate, shoes, hardware and wheel cylinder as a loaded assembly.

the missing boot is most likely from the warm bearing.

 

[poconojoe]

The shoes are completely unadjusted as they can be. What I mean is, they are touching the post on top and the adjuster is completely in on the bottom. It makes no sense.
I'll take the drum back off and take another look. Something is not right. I will report back.
Scott, I like your idea of replacing the whole thing. Do I need to replace the other side at the same time? On a car or truck I would never do just one side.

 

[poconojoe]

It seems the brake shoes only drag when I tighten the castle nut for the drum. In order for the brakes to not drag, the castle nut has to be real loose. Loose enough that I can feel a very, very slight rocking of the drum. Are my bearings gone maybe? They look good by appearance.

 

[fhhuber]

I've never seen correctly installed drum brakes with the adjuster all the way as loose as it can go.

Something is not put together right or you have the wrong shoes.

Did you properly compress the wheel's brake cylinder? If that isn't pressed in, you can get the result described. As the shoes wear the pistons come out further.

 

[poconojoe]

I've never seen correctly installed drum brakes with the adjuster all the way as loose as it can go.

Something is not put together right or you have the wrong shoes.

Did you properly compress the wheel's brake cylinder? If that isn't pressed in, you can get the result described. As the shoes wear the pistons come out further.

I agree that the adjuster should have more play. Never have seen that either. I did compress the new wheel cylinder and the shoes are in all the way. The shoes are making contact with the top stud, so the wheel cylinder is not pushing the shoe out.
What do you think about my last post concerning the bearings? As I tighten the castle nut the drum gets too tight. I know the castle nut should be tightened to seat the bearing, then backed off a bit. But in order to get no drag on the brakes, that castle nut has to be only finger tight and there is a tiny bit of play back and forth on the drum. The play might be less than a mm. I'm thinking the bearings are bad or maybe I'm being too anal?

 

[fhhuber]

if the side of the shoe is contacting the drum... there's a couple of possible causes.

Drum not turned properly leaving a lip.

Shoes not installed properly spacing them out

and yes, worn bearing. But the bearing normally won't be the culprit if its not REALLY bad (or the wrong bearing)
Since it wasn't making the old shoes drag, the bearing is almost certainly not it.

But if the bearing is worn... it can feel like a dragging brake and it not be the brake.
The shoes should have evidence of where they were dragging. If no evidence that the shoes were dragging on the drum, then maybe it is just a worn out bearing.
You can test this... pull the shoes out (and anything else that just hangs because of the shoes being out. See if you can properly adjust the bearing.

 

[poconojoe]

You can test this... pull the shoes out (and anything else that just hangs because of the shoes being out. See if you can properly adjust the bearing.

This is a great idea!

 

[fhhuber]

Also... check of you got the shoes "on the wrong feet" as it were... Sometimes the web isn't quite centered. Then it matters because the web will push the brake shoes out and make them rub.

https://upload.wikimedia.org/wikipedia/commons/thumb/2/28/BRAKE_SHOE.jpg/220px-BRAKE_SHOE.jpg

 

[mla2ofus]

Did you get the return springs installed properly?
Mike

 

[poconojoe]

Also... check of you got the shoes "on the wrong feet" as it were... Sometimes the web isn't quite centered. Then it matters because the web will push the brake shoes out and make them rub.

https://upload.wikimedia.org/wikiped...BRAKE_SHOE.jpg

Never took the shoes completely off when I replaced the wheel cylinder.
The shorter shoe is up front. Right?
I'm leaning toward the bearings since when the castle nut is snug, the shoes bind up.

 

[poconojoe]

What is the exact procedure for tightening the castle nut?
When doing automotive drum brakes, there is usually a specified torque value to set the bearings. Then you back the castle nut up a specified amount. Maybe 1/4 turn or so. Then install the cotter pin.

 

[fhhuber]

Find the manual for your spindle to verify... but typical is to tighten JUST until the bearing is a bit draggy. Rotate the wheel several turns, then loosen just until the wheel spins freely and you can put in the cotter pin. No real torque spec.

http://www.championtrailers.com/pre-loading-trailer-wheel-bearings/

If the wheel quits dragging on its own before you loosened the nut... you need to tighten till it drags again and spin it a few more turns THEN loosen just to where it spins freely.

 

[poconojoe]

Fhhuber, thanks for that explanation!
I was pretty much doing it right, but had to loosen it a bit more to line up the cotter pin hole.
Maybe the tab washer in lieu of the cotter pin would be better.

 

[bruceb58]

What is the exact procedure for tightening the castle nut?
When doing automotive drum brakes, there is usually a specified torque value to set the bearings. Then you back the castle nut up a specified amount. Maybe 1/4 turn or so. Then install the cotter pin.

Yes, follow the instructions in the link fhhuber gave you. That's exactly how I do mine and I do use a torque wrench. You need to make sure you spin the wheel while tightening the nut to 20ftlbs. Then back off nut and finger tight until the cotter pin lines up. Better to have slightly loose if the cotter pin doesn't match up perfectly.

 

[poconojoe]

Yes, excellent instructions! Thanks everyone! I guess I'm at fault for making that castle nut too tight. I was afraid of it being too loose when lining up the cotter pin.

 

[NYBo]

Adjusting the spindle nut will have no effect on the brakes, so I think you have found the real culprit. Once you get the bearing situation sorted out, don't forget to properly adjust the brakes.