Trailer repair installed wrong disc actuator on 2 axle drum trailer

[Maetar]

Hello - trailer repair nightmare, trying to wake up. Took my 8000# max weight dual axle drum brakes boat trailer for repair: 1st time I picked it up, they said existing system checked good/flushed systeme, BUT all fluid leaked out by the time I got home; 2nd time they installed a new Dexter A60 (2K underweight), tried to assure me it was the A84 but it wasn't; 3rd time, yesterday, they installed a Dexter DX8.5L which clearly had "DISK BRAKES" sticker on it, my trailer has drum brakes. NEVER going there again (Eagle Trailer, Rathdrum, ID). Question please: do I need to immediately take the trailer to a reputable repair shop to remove the disc brake actuator and replace with drum? I can tell the brakes are working, what are the risks of just leaving the disc actuator on there? I live in North Idaho, short drive to various lakes, in August driving 5 hours to San Juan Islands, Pacific Ocean, over I couple mountain passes. Want to make sure the trailer is safe. Thanks for your advice.

 

[dingbat]

Hello - trailer repair nightmare, trying to wake up. Took my 8000# max weight dual axle drum brakes boat trailer for repair: 1st time I picked it up, they said existing system checked good/flushed systeme, BUT all fluid leaked out by the time I got home; 2nd time they installed a new Dexter A60 (2K underweight), tried to assure me it was the A84 but it wasn't; 3rd time, yesterday, they installed a Dexter DX8.5L which clearly had "DISK BRAKES" sticker on it, my trailer has drum brakes. NEVER going there again (Eagle Trailer, Rathdrum, ID). Question please: do I need to immediately take the trailer to a reputable repair shop to remove the disc brake actuator and replace with drum? I can tell the brakes are working, what are the risks of just leaving the disc actuator on there? I live in North Idaho, short drive to various lakes, in August driving 5 hours to San Juan Islands, Pacific Ocean, over I couple mountain passes. Want to make sure the trailer is safe. Thanks for your advice.

No problem using a disc brake actuator on drum brakes. Cant use disc on drum.

From what I’m seeing the Dexter A60 looks to be #7500.

How much does you boat and trailer weigh?

https://www.etrailer.com/Brake-Actuator/Dexter-Axle/DX56FR.html

 

[Maetar]

No problem using a disc brake actuator on drum brakes. Cant use disc on drum.

From what I’m seeing the Dexter A60 looks to be #7500.

How much does you boat and trailer weigh?

https://www.etrailer.com/Brake-Actuator/Dexter-Axle/DX56FR.html

Hi, thanks for the quick response. Would you clarify your statement on top, did you mean to say "can't use drum on disc"? Boat is a Bayliner 245, loaded up with all gear, 65 gallons gas, fresh water, close to the 8,000 pound limit on the trailer. I have a 17K stinger with 10K ball.

 

[Lou C]

Drum brake actuators use a check valve to maintain pressure in the wheel cylinders, so I'm not sure that a disc brake actuator (no check valve) will work with drum brakes.

How to Remove a Residual Valve from a Master Cylinder | Modify your drum master cylinder for disc brakes | Champion Trailers

How to Remove a Residual Valve from a Master Cylinder to change it from Drum to Disc brake ready.

www.championtrailers.com

 

[dingbat]

Hi, thanks for the quick response. Would you clarify your statement on top, did you mean to say "can't use drum on disc"?

You can not use a drum brake actuator on disc brakes (unless you drill out the fluid port) but you can use a disc brake actuator on drum brakes.

Boat is a Bayliner 245, loaded up with all gear, 65 gallons gas, fresh water, close to the 8,000 pound limit on the trailer. I have a 17K stinger with 10K ball.

I think your over estimating your weight by a good bit.

Dry weight is #5,248 with a load capacity of #1,600 for a total of #6,848. If your boat weighs more than that your overloaded.

 

[Horigan]

Call Dexter and ask them. The master cylinder piston size is likely different between drum and disc actuators. So the actuator will either run out of travel or won’t generate enough pressure. You could just swap the actuators.

 

[dingbat]

Drum brake actuators use a check valve to maintain pressure in the wheel cylinders, so I'm not sure that a disc brake actuator (no check valve) will work with drum brakes.

Think about it…if the brakes wouldn’t work w/o the check valve, how does a backing solenoid work?
In effect your dumping the “residual” pressure back to the supply.

UFP Reverse Flow Brake Actuator Solenoid - 3/8" Thread

UFP Reverse Flow Brake Actuator Solenoid - 3/8" Thread

trailerparts.com

 

[Lou C]

It’s not that they won’t work it’s that the response would be delayed and total braking force would be less than optimal. I don’t think the trailer companies would spend the extra $$ to design & build 2 different actuator master cyls for the same actuator if this wasn’t so…

 

[Maetar]

Thanks all for your feedback. I'm going to leave the disk brake version installed and hook up the solenoid to ensure the surge brake does not function when backing my boat uphill driveway.
Rich, as you suggested, I called Dexter and their VP of Marine Sales, Bill O'Hara said this:

The disc version, which you have, will work fine for your drum brakes. Also, you can hook up the solenoid, but your trailer manufacturer likely uses free-backing hydraulic brakes. These disengage mechanically when backing so the solenoid will not be needed. Regarding an instruction sheet, I have to apologize as we do not have this completed. You have our newest actuator, which got released prior to the literature. I did attach our surge actuator tri-fold for your reference though that shows your actuator.



Happy boating!



Bill O’Hara | Vice President of Sales, Marine
Dexter – Atlanta, GA (Marine Headquarters)
bohara@dexteraxle.com
direct tel: (470) 809-7136 | cell: (574) 596-7310

5600 Bucknell Drive, Atlanta, Georgia, 30336, USA
fax: (404) 344-0296 | main tel: (404) 477-6899
A DexKo Global Company ■ Together is Better
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[dingbat]

It’s not that they won’t work it’s that the response would be delayed and total braking force would be less than optimal.

Agree. Response would be slower (milliseconds). Pressure would not change.

I don’t think the trailer companies would spend the extra $$ to design & build 2 different actuator master cyls for the same actuator if this wasn’t so…

The master cylinders are the same with the exception of the size of the hole in the “check valve” and the disc cylinder would have a 1/8" NPT hole for the backup solenoid.

Back in the days before they marketed both, actuators came with a label that said not for use with disc brakes with instructions on how to modify for disc brake usage in the installation manual.

The “check valve” is actually a brass pipe plug with a small hole (0.03”?) in the middle. You simply drilled the hole out to 0.156” when using disc and installed back in the coupler.

Guessing they started marketing separate actuators for convenience but probably more so for liability issues.

 

[Lou C]

Agree. Response would be slower (milliseconds). Pressure would not change.


The master cylinders are the same with the exception of the size of the hole in the “check valve” and the disc cylinder would have a 1/8" NPT hole for the backup solenoid.

Back in the days before they marketed both, actuators came with a label that said not for use with disc brakes with instructions on how to modify for disc brake usage in the installation manual.

The “check valve” is actually a brass pipe plug with a small hole (0.03”?) in the middle. You simply drilled the hole out to 0.156” when using disc and installed back in the coupler.

Guessing they started marketing separate actuators for convenience but probably more so for liability issues.

Read the link to ChampionTrailers that I posted above. The residual pressure valve is inside the master cyl. To remove it you’re basically taking the whole thing apart.
What you’re referring to is the orifice (opening) in the fitting that you connect to the brake line. This has to be larger in a disc actuator for disc brakes to release.

 

[Lou C]

https://www.tiedown.com/wp-content/uploads/pdf/c100.pdf

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