RV Education
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Mike Wilson is a RVDA Certified Master RV
Tech. with over 25 years experience and now he's sharing his
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and developer for The RV Help
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Braking Units M&G Braking Unit Air-Brakes
M&G Braking Unit
M&G braking is a good choice for coaches with air brakes. The advantage M&G has over other braking units is inside the towed vehicle. There is nothing to install inside. The braking unit attaches to the brake master cylinder under the hood. It is operated by air pressure coming from the coach. It applies the brake by pushing the rod connected to the master cylinder just as the brake pedal does while driving.
M&G braking is not available for all vehicles. It is not a universal kit. Each unit fits a specific vehicle. Some vehicles do not have enough space available to fit the M&G unit.
To install an M&G unit you will need to remove the master cylinder from the brake power unit. Do not remove any brake lines. Be careful not to pull very hard on the brake lines. Do not bend sharply or kink any lines. You will need to gently move the brake lines enough to fit the M&G unit between the master cylinder and power brake unit. There is a rod included with the M&G that will need adjustment. The details are outlined in the instructions. Basically there needs to be a slight amount of “free play” between the brake pedal and master cylinder. This “free play” is necessary to be certain the brakes do not hang on or drag. You will need to install and remove the M&G several times to adjust and check the “free play”. Once the rod is adjusted and thread locker is applied, you can tighten the unit. Check the brake lines to be sure there are no sharp bends or kinks. Gently move the lines so any objects close can not touch the lines.
The coach connections, air line routing, and BreakAway are exactly the same as Blue Ox and Roadmaster’s air braking units. You can refer to that article for details.
M&G makes a system for coaches with hydraulic brakes. It incorporates an air pump in addition to the rest of the system. In my opinion: Because of the additional potential problems and costs involved, I do not recommend this system. There are other systems that work well with hydraulic coach brakes. Please refer to those articles for details