Mounting Bolt Hole Dimensions for Demco Hydraulic Trailer Brake Actuator # DM72VR

Question

Question:

Hi, We are trailer manufacturers and we have requests to make trailers for your customers who wish to use the above actuator. Can you provide us with a drawing to show the hole positions for mounting to the draw bar ?

asked by: Trevor H

0

Expert Reply:

The mounting bolt holes on the Demco Hydraulic Trailer Brake Actuator # DM72VR that you referenced are spaced apart exactly 3 inches, on center. From the center of the rear bolt hole to the end of the unit there is a distance of just under an inch (15/16 inch to be exact). The holes are 1/2 inch in diameter.

I have attached an image with these dimensions labeled along with a couple additional dimensional diagrams for this actuator that you can check out. Just let me know if you need any other specific measurements and I will be happy to take them.

expert reply by: Chris R

0

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Answer 1

The manual lockout on your Atwood 85778 surge brake coupler is there so that you can back up the trailer without the brakes locking up on you. Yes you can safely tow your trailer with the broken manual lockout, you just have to make sure you…

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Answer 2

Yes, you'll need to use all of the mounting holes on the Demco Hydraulic Brake Actuator part #DM72VR in order to be covered under warranty or retain the capacity rating. Unfortunately, if one of the holes does not line up with an existing this…

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Answer 3

Thanks for the photo. That is a great help for getting you the correct replacement. I recommend the Demco Hydraulic Trailer Brake Actuator - Drum Brakes - Zinc Plated - 2" Ball - 7,000 lbs #DM72VR for a zinc plated option. This coupler does not…

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Answer 4

I have attached a video for you to help you bleed the surge brakes and also given an explanation below. You want to top off the master cylinder and pump the fluid from the master cylinder. You can do this by unbolting the plate that holds the lever…

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Answer 5

You can certainly go ahead and re use the existing 2 bolts, provided they are in good condition. The fish wire method shown in the video works too, but it is also very common to just use the two bolts like your old Atwood actuator. Personally I would…

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Answer 6

Yes, you can use the inner member from the #DX27FR and the #DX83FR interchangeably. Although they are designed to fit different trailer tongue sizes, they both use the same inner member #DX97FR. You could either purchase the inner member separately…

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Answer 7

I went out to the warehouse and measured the Demco Hydraulic Brake Actuator item #DM72VR. The bolt hole spread is 3". I have linked a diagram below. I have linked a diagram I made below and another one that will show you a few dimensions.

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Answer 8

I do have an option for you but the coupler on your trailer is very old and we simply don't carry parts for them anymore as they were discontinued by the manufacturer. Therefore, the only option we can offer is a new coupler, the Demco Hydraulic…

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Answer 9

It sounds like you're asking about the torque spec for the castle nut on your 3,500 lb axle. There is no specific torque rating when installing the castle nut on any axle. You want to run the nut down until there is no side to side play in the…

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Answer 10

I have attached for you below a photo which shows the bolt pattern for the Demco Hydraulic Brake Actuator part #DM72VR.

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Answer 11

Thanks for the picture of your actuator that you are wanting to replace. The Demco Hydraulic Actuator part #DM8609502 would be a great option as it is designed to fit A-frames like yours. It has an 8k capacity, designed for a 2 inch hitch ball, and…

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Answer 12

You have the dreaded, no longer available Atwood surge coupler on your trailer. Since Atwood was bought out and the production was stopped on the actuators there are no replacement parts for your actuator. There's no easy way to lock that coupler…

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Mounting Bolt Hole Dimensions for Demco Hydraulic Trailer Brake Actuator # DM72VR

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