Thursday, January 27, 2022


All your trailer brakes should lock up at the same point

By Chris Dougherty
Chris Dougherty is a certified RV technician. Here is a letter he received from a reader while he was serving as’s technical editor.

Dear Chris,
I have a new Coleman camper that seems to have a brake issue. While it stops okay, one tire seems to lock up first. This happens while adjusting the brake controller. I feel that I would have better braking and a shorter stopping distance if all four tires locked at about the same time. I know that I don’t need — or want — the brakes locking the wheels in normal use. But while making adjustments to the controller I would like to have them better synchronized. Is there a way to adjust the brakes to get them all braking together?

Dear Jeff,
Absolutely, the brakes can be adjusted. I’m going to assume that the trailer is level for towing, and the tires are all inflated properly. If one wheel is grabbing and the other aren’t, and the trailer isn’t equipped with self-adjusting brakes, then there is a procedure for adjusting the brakes on each wheel position, and I would recommend going through this procedure for all the wheels so you know they are adjusted properly.

I’m not sure which axle/brake system you have on your unit, but here’s Dexter Axle’s directions for adjusting the brakes, right out of their Operation, Maintenance and Service Manual. By the way, you should have a book in your owner’s packet about the axles and brakes for your RV. If not, they’re available online from the axle manufacturer … just look for the ID sticker on one of the axles.

Brake Adjustment
Brakes should be adjusted: (1) after the first 200 miles of operation when the brake shoes and drums have “seated,” (2) at 3,000-mile intervals, (3) or as use and performance require. The brakes should be adjusted in the following manner:

1. Jack up the trailer and secure on adequate capacity jack stands. Follow trailer manufacturer’s recommendations for lifting and supporting the unit. Make sure the wheel and drum rotates freely.

2. Remove the adjusting hole cover from the adjusting slot on the bottom of the brake backing plate.

3. With a screwdriver or standard adjusting tool, rotate the starwheel of the adjuster assembly to expand the brake shoes. Adjust the brake shoes out until the pressure of the linings against the drum makes the wheel very difficult to turn.

Note: For drop spindle axles, a modified adjusting tool may be necessary.

4. Then rotate the starwheel in the opposite direction until the wheel turns freely with a slight lining drag.

5. Replace the adjusting hole cover and lower the wheel to the ground.

6. Repeat the above procedure on all brakes. For best results, the brakes should all be set at the same clearance.

After this is done, repeat the adjustment and synchronizing procedure for your brake controller. If you’re not comfortable doing this, any RVDA/RVIA Certified Technician can perform this procedure for you. Also, if this doesn’t fix the problem, occasionally there can be a mechanical problem inside the hub, and that should be serviced.

##RVT794 ##RVDT1324


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Gene Cheatham
1 year ago

One additional check while the wheels are off the ground to get an idea if the drum is out of round can be done.
After the adjustment is done note if the wheel rotates with the same resistance all the way around. If it binds in a spot, your drum may be out of round needing turned or replacing.
A replacement may be cheaper, however even a new Chinese made drum could be out of round from the factory.

1 year ago

We tow a 2020 40+ft solitude with a 2016 F-450 with the controller set to max. They will stop, eventually, the truck from idle for the connection test, but under normal or heavy braking, I don’t believe they’re doing very much at all.

1 year ago
Reply to  Matt

Then get it checked and FIXED! You’re an accident waiting to happen! Please!

Tommy Molnar
4 years ago

Trailer brakes have been a hassle for us for over 20 years. This past Feb at the Good Sam RV Rally in Phoenix, I bit the bullet and went for a disc brake upgrade on our trailer and have never looked back. The difference is mind boggling! No more worry about whether we can stop for that just-changed traffic light. And no adjustment needed, just like your car. Not cheap, but worth every dollar.

4 years ago

From my experience, you don’t want the brakes on the RV to lock up at all. My understanding is they are there to “assist” in stopping. Once you lock up your RV wheels your RV can start to skid and you have no control which direction it then goes. Set up your brake controller to the point just “before” they lock up.

Mel Goddard
4 years ago
Reply to  George

So, when under brake test, and the wheels ‘lock up’ , just reduce the gain until they are just at the point of lock up, but not locking.

That is the point at which vertualy all anti -skid systems are set at.