It's those damn disc brake calipers again

colbysmith

Ok, I swear I'm going back to all electric sooner than later. I'm still having issues with the disc brake calipers on my trailer. The issue seems to be the rubber bushing that the slider pin goes into, are coming out somewhere while driving down the road.

This is a picture of what they look like:

And this is a picture of one missing:

Fortunately, I'm catching them before the pin fails from the caliper bouncing around it. And I purchased some extra bushings and caps. I've had two, and again on the starboard side of the trailer, come out and go missing after 1000 miles of driving, and then the next one after another 500 miles. That seems to be about when they come out, 1000-1500 miles. I've got the brakes set to medium on my F150's controller, and I"m not braking hard or riding the brakes. I'm open to suggestions. But if I have to buy more expensive calipers, right now I can change over to fully electric for what a couple of the current calipers cost! Mad

Colby

jkidd · Posted: Fri May 31, 2024 9:56 pm Post subject:

Boy you have got me. I have been towing mine around since 2007 and haven't had a problem with them. In 2022 when we went to alaska I replaced the brakes and bearings. When I pulled the right front I found that the factory never put the cotter pin in that wheel holding the nut on. From 2007 to 2022 and the I turned the nut off with my fingers. I didn't find any broken parts on the brakes.

alainP · Posted: Sat Jun 01, 2024 12:56 pm Post subject:

Colby, we have the same trailer but different calipers.
I you decide to stick with hydraulic consider the Tie Down Engineering Calipers #46304. No rubber bushings with the pins, all metal. Never had a problem with them coming loose. Your trailer is fairly new, any feed back from LoadRite on this recuring brake failure. Seems it should get their attention.

Avidmagnum12 · Posted: Sat Jun 01, 2024 5:07 pm Post subject:

I have the same ones as Alain. No rubber bushings. I agree with him that you should contact LoadRite. The only problems I’ve had with mine were caused by the operator! 😁

colbysmith · Posted: Sat Jun 01, 2024 7:56 pm Post subject:

I'll have to look into those that you two have. (Alain and Tom). I doubt Loadrite would have any assistance to offer. They still think the 5ah battery is enough for the EOH brake system. (DOT requires 9ah.) I do think I'll try harder to get a hold of Dexter to see what they have to say. Late addition, I just looked those calipers up. $172/piece. For the price of two of them I can convert my EOH system to Electric only on both axles! If I sold my calipers with new brake pads and cleaned up for $100/piece, and the actuator for $500, I'd be about $500 ahead, and somebody could have a really nice EOH system. Mr. Green

I really can't figure out why I'm having problems with those rubber bushings, while others are running the same thing without an issue. And it seems to just be on the starboard side! Colby Confused

Dora~Jean · Posted: Sun Jun 02, 2024 1:55 pm Post subject:

I too have never had this kind of problem with my disc calipers, I’ve had other problems, but not this. I’ve been running Kodiak Stainless Steel calipers for the past 5 yrs or so with my EOH system and over 10,000 miles, no issues.

In your picture of the rubber bushing (that is present), is it a dust cover or a bushing/dust cover combination? I’m not clear what the purpose of that rubber bushing is — to keep the caliper’s sliding pin centered and absorb vibration? I’ll have to look at mine to see if they have such bushings. My first thought is that they might be melting away from excessive heat.

colbysmith · Posted: Sun Jun 02, 2024 11:07 pm Post subject:

colbysmith · Posted: Tue Jun 04, 2024 11:02 pm Post subject:

I sent an email thru their website contact page to Loadrite and Dexter yesterday. No response as of yet today. But I decided to pull all the slider pins and grease them with some synthetic disc brake grease that is safe to use on rubber and plastic. None of the pins had grease on them. I had two new calipers on the starboard side from an earlier replacement, and neither of them showed any signs of grease on the slider pins. I do have one more new caliper in my shop, and when I pulled it, I noticed a small amount (very small amount) of silicone grease on it's slider pin. SO as of now, I have greased all 8 slider pins on the trailer calipers, and also on the two spare calipers I carry in the truck, and the one spare I have at home. (Two of my spare calipers are the ones that came apart when the slider pins came off last year on my drive out for the Delta cruise. I rebuilt them and replaced the brake pads.) My thought process is that the lack of grease on the slider pins caused the rubber bushings to push out as the slider pins moved back in forth inside them. Why only on the starboard side, I don't know... Time will tell if this resolves the problem.

Dora~Jean · Posted: Thu Jun 06, 2024 12:32 pm Post subject:

I don’t know the temperature rating of the grease you used, I would think silicon grease is very low temp. Maybe a super-thin coating of disc brake grease (400°+) might be good? I think I used a marine waterproof grease on mine (probably not high temp). I’ll have to rethink how I grease those pins next time I’m in there.

alainP · Posted: Thu Jun 06, 2024 12:47 pm Post subject:

There is a possibility that the 2 Calipers on that side suffer from a manufacturing defect and the holes for the rubber inserts are slightly oversized

colbysmith · Posted: Thu Jun 06, 2024 6:48 pm Post subject:

Moxieabs · Posted: Sun Jun 09, 2024 9:01 am Post subject:

Just thinking out loud, maybe the rotors are the problem(wrapped) forcing the calipers to move excessively and working the bushings out in the process? Although, two on the same side seems too coincidental.

colbysmith · Posted: Sun Jun 09, 2024 8:24 pm Post subject:

Hm, possible. But I don't think they are warped. None the less, I'll take a closer look at them sometime this week.

colbysmith · Posted: Sun Jun 15, 2025 5:49 pm Post subject:

Well, here we go again.
My boat trailer has EOH disc brakes. The calipers have a rubber bushing, or boot, that the slider pin goes through. (Part number 33305 if that matters.) After about 5000 miles these rubber boots start to disintegrate and/or disappear. If I don’t catch it in time, this will cause the slider pin to eventually break off or vibrate out, then allowing the caliper to fall off. Surprisingly these calipers came from the manufacturer with dry slider pins. I’ve found the rubber boots will last longer if I grease the slider pins before long trips. The rear axle seems to have more of an issue with this. After my last long (5000 miles) trip, I found both rubber boots missing on one rear brake and both starting to disintegrate on the other rear brake. Why? I suspect heat is part of the problem.

Above was my post on facebook. I'm convinced now that the rubber boots are not holding up to the heat. If you look close at the boots, they appear to be a heat factor destroying them. The more expensive calipers Tom and Alain have mentioned in the past run almost $200. The ones I'm currently using are around $165. I can replace all four brakes with new drums and electric brakes for a little more than the cost of two calipers. I have had a suggestion to see if I can find some silicone boots, or something that is more heat resistant. It seems I only have an issue with the boots after several thousand miles, and that usually after going over one or several mountain passes several times. I tend to use engine braking, but still need to apply additional braking. I don't believe I am using excessive braking, but none the less, the brakes are going to get hot. I never heard back from Dexter earlier. I'm still trying to solve the problem, and just wanted to bring it back up again. Adding your brake calipers to your checklist for trailering is probably worthwhile. Here are some photos of the caliper slider pin boots that were partially destroyed, but still in their seat.