Lowboy trailer brakes

southernman13 · Dec 3, 2019

We have 88’ trial king with 15” Dayton wheels. One side of trailer the brakes were shot. We took them off and installed new shoes drums seals and bearings. First one went real well. Second one doesn’t seem right. We put it back together and only on that one wheel when I adjust slack adjuster the arm on slack adjuster moves in or out. All the other wheels the shaft that goes through the slack adjuster moves not what slack adjuster itself. Is maybe the air chamber bad allowing it to move. Something just not right with it. We haven’t driven it yet. Please advise. I know everything needs to be greased we haven’t done that yet but all parts seem to be free and moving. Thanks

bam1968 · Dec 3, 2019

I am thinking you might have a spring broke in your brake chamber. Either that or your S cam is froze up but since you just replaced the shoes my guess would be brake chamber.

southernman13 · Dec 3, 2019

K thanks I do know the s cam isn’t froze. I was just thinking if I strap the arm down on slack adjuster where it can’t move the try it. That should tell me if the chamber is bad. Thanks bud

Theweldor · Dec 3, 2019

If the arm on the slack adjuster is pulling out the brake chamber you are turning it the wrong direction. Is the slack mounted with the adjuster on opposite of the other one. If you also replaced cams is it possible they sent the wrong one. There is a right and left.

southernman13 · Dec 3, 2019

If it has wrong parts they been in there a long time. We just got it recently but hasn’t been touched in quite a while. The shoes and drum on that wheel we’re worn slap out and the brake spring was stretched out of whack. It’s definitely pulling the arm out of the chamber. It acts like it’s over center but can’t be it now has new shoes and new drum. Really isn’t any adjustment on it yet. The only time it acts right is when I run it all the way in and the slack adjuster arm bottoms out the chamber then the shaft will move. Idk. Im probably very confusing.

Theweldor · Dec 3, 2019

The arm bottoming out the chamber is exactly what you want it to do. It could be a bad spring in the chamber as mentioned above. Can you put air to it and check that the chamber extends and returns properly. Although chambers are pretty cheap. If trying to adjust the brakes pulls the chamber out you are going the wrong direction. You should be able to see the shoes expand to the drum as you turn the adjuster. SO you didn't change the cams I take it.

southernman13 · Dec 3, 2019

No change of the cams. I’ll have to look again but with all the other ones the arm doesn’t move no matter which way your going in or out and you can see the shoes move in and out. Yes the brake chamber moves in and out when you hit the brakes. Trying to adjust them is where it’s not working right

southernman13 · Dec 3, 2019

Another dude just told me slack adjuster is probably the culprit.

DMiller · Dec 3, 2019

If are developing enough force to rotate the Slack Out of the chamber are adjusting backward or has had the wrong cam in it forever. Only way it will pull Out and not push in is if rotate the adjustment the wrong way.

Theweldor · Dec 3, 2019

Does it have maxi's on all the axles?
Pictures would help quite a bit if you have the time. It is confusing as to why one would work and one not.
As you say they must have worked before because they were wore out.

southernman13 · Dec 3, 2019

Not sure what maxies are. I’ll take pics tomorrow if I can. Thanks

DMiller · Dec 3, 2019

Maxi's are Spring Brake Parking Chambers.

southernman13 · Dec 3, 2019

No it’s a single chamber

DMiller · Dec 3, 2019

With no air in the system these should be in the Released, relaxed state, if you have the slack adjuster loose to the can(Not adjusted tight in or out) should be able to pull on slack adjuster and apply the brake or at least get shoes to move outward.. If Not, if is Tight either the S cam is locked in place or the S cam is backward to operate.

The direction of travel is OUT and that direction of rotation is on the Backside of the "S"

southernman13 · Dec 3, 2019

The s cam will move. When brake is applied. It operates correct. It when I try to adjust them that isn’t working properly. I can only see one way the s cam can be installed. If you turn it over it’s the same.

RZucker · Dec 3, 2019

southernman13 said:
The s cam will move. When brake is applied. It operates correct. It when I try to adjust them that isn’t working properly. I can only see one way the s cam can be installed. If you turn it over it’s the same.

What exactly happens when you try to adjust it? The adjuster is basically a screw and turns the cam in or out. Is it stripped and turns with no resistance? Or?

92U 3406 · Dec 3, 2019

Based on what I'm reading I'd have to go with what everyone else is saying.

When you are adjusting this brake, watch the direction the cam rotates. When you snug it up, the cam should be rotating the same way as if you were stepping on the brake pedal. If it isn't, you're turning the adjuster the wrong way.

southernman13 · Dec 4, 2019

I’m not turning it the wrong way. I know how to adjust them. All three of the other brakes work fine. This one wheel when you try to adjust the brakes the slack adjuster moves. The shaft doesn’t move back and forth like it’s supposed to and like all three other wheels. It’s not moving the cam the slack adjuster moves in lieu of the s cam shaft

bam1968 · Dec 4, 2019

I have seen a few trailers that have the brake chamber on the top side of the axle and the slack adjuster is basically upside down. If that is the case wouldn't it adjust the opposite way than if it was 'right side up'??

sled dog · Dec 4, 2019

With the slack unhooked from the cam, can you move the cam freely? If the cam turns hard, it would be easier for the slack to pull the chamber rod than move the cam

Lowboy trailer brakes

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