Process to Convert Trailer from Air-Over-Hydraulic Brakes to Electric-Over-Hydraulic Brakes

Question

Question:

I am looking to convert air/hydraulic brakes to electric/hydraulic brakes. Company i am doing work for has six military Marine Corp Tactical Welding Shop trailers they want to be able to pull with multiple f550 trucks of various years. I can not find any information on what brake system these trailer have. They are single axle / single wheel set up with 16 inch brakes. Any help would be greatly appreciated. Thank You

asked by: Randy R

1

Helpful Expert Reply:

If the brakes assemblies and hubs/drums on the subject trailers are actually 16-inches in diameter we have no compatible brakes. The largest electric and hydraulic drum brakes we have are 12-1/4 x 5, such as the left/right electric brake set # AKEBRK-12 which is rated for a 12K axle and the left/right hydraulic set # 23-408-409 also rated for 12K axles.

We do have electric-over-hydraulic (EOH) actuators like the HydraStar Drum Brake Actuator # HBA-10 and the others shown on the linked page. These can be used to take in an electrical brake signal from a brake controller like the excellent Prodigy P3 # 90195 and convert that electrical input signal to hydraulic fluid pressure to operate hydraulic brakes on the trailer.

I linked an article that you may find helpful. It covers the process of converting a trailer to EOH drum brake operation.

expert reply by: Adam R

1

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Answer 1

In order to determine the torque rating for the lug nuts on your trailer you will need to know check out the chart I attached that shows all of the torque specs for all the trailer lugs available based on stud size, wheel material and wheel size.

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Answer 2

I apologize for any confusion on what the proper torque specs are for 1/2 inch lug nuts on trailer wheels. I attached a picture of a chart to the right that details what the proper torque specs are for a trailer wheels lugs based on lug size, wheel…

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Answer 3

To determine the size of the brake assemblies you need you have to measure the depth and width of the hub drum on the axle like what you see in the picture I attached. The most common size is 2-1/4 inch wide like the #T4071600-500 that you…

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Answer 4

Hey Richard, thanks for reaching out! The Dexter DX7.5 Drop-N-Go Brake Actuator #099-175-00 is a great option for a replacement actuator because it's a direct replacement for the common Model 60 actuators that were popular in the '90s.…

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Answer 5

Even though I cannot comment specifically on the grease you used because I am not familiar with it, I can tell you the best grease for trailer bearings is a a grease with a rating of GC-LB, which just means it is made to withstand very high…

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Answer 6

To find the load capacity for your axle you should look on the trailer VIN plate or sticker that lists the VIN number. The weight rating of the axle should be listed on that same plate or sticker. Also, the axle could have a tag or plate on it that…

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Answer 7

Torque specs for wheel lug nuts will vary depending on the diameter of the lugs, type of lug nut and the wheel's material. The linked chart details the recommended torque for many combinations. Dexter Hub/Drum #84546UC3 has 1/2-inch studs and…

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Answer 8

To determine the size of the hub assembly you need to purchase you have to determine which bearings are in the old assembly. If the old assembly has L44649 inner bearings, you would use the hub you chose #8-258-5UC1. If the inner bearings are marked…

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Answer 9

Depending on how the trailer was made, there will be a few spots you can check to identify the axle. First, if the trailer was pre-made by a specific company, you may be able to find this information in either the paperwork or on a placard somewhere…

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Answer 10

The torque for the Dexter Trailer Hub and Drum Assembly - 6,000-lb and 7,000-lb Axles - 12" - 5 Spoke Utility #8-174-5UC3 is not specified by the manufacturer. For 9/16 inch studs, the typical lug nut torque will be 120-140 ft lbs based on most…

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Answer 11

Traditionally, trailer manufacturers did not use electric brakes on boat trailers because the brake magnet wiring and trailer wiring did not always have the best insulation or water protection. These days, more and more manufacturers are using…

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Answer 12

The difference between an load range C and load range D tire in the same size is the capacity and psi rating. The two tires will still have the same dimensions and fit on the same wheel. The D rated tire has a higher capacity. For a ST175/80D13 like…

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