DM800 Posted October 22, 2016 Share Posted October 22, 2016 Hi I have just acquired a 79 DM800 it is in need of finishing the resto was started over 10 years ago. the truck was from Michigan originally and has a ntc 400. I know it has 44k rears but the front axle is interesting, it has disk brakes! Air over hydrolic. I have been told that those systems were prone to failure and didn't work well. Maybe the reason it it disconnected. I want to install a conventional axle with air brakes I am assuming it is a heavier axle 20k? The numbers on the axle : IQHA251P FAW616D i would like to know if it is a 20k axle. Thanks steve Quote Link to comment https://www.bigmacktrucks.com/topic/47387-front-axle-with-disk-brakes/ Share on other sites More sharing options...
j hancock Posted October 22, 2016 Share Posted October 22, 2016 FAW616D is an 18,000 axle. Quote JimIt doesn't cost anything to pay attention. Link to comment https://www.bigmacktrucks.com/topic/47387-front-axle-with-disk-brakes/#findComment-349570 Share on other sites More sharing options...
DM800 Posted October 23, 2016 Author Share Posted October 23, 2016 Thanks for the info j Hancock Quote Link to comment https://www.bigmacktrucks.com/topic/47387-front-axle-with-disk-brakes/#findComment-349715 Share on other sites More sharing options...
Vladislav Posted October 24, 2016 Share Posted October 24, 2016 The axle with the brakes of the style you describes is fitted in my DMM Mack. And it's a standart factory equipment. Discs with hydraulic calipers. And damn air/juice mixed setup on the left framerail to activate it. I have no knowledge of how it actually works though. The truck is not running. Quote Никогда не бывает слишком много грузовиков! leversole 11.2012 Link to comment https://www.bigmacktrucks.com/topic/47387-front-axle-with-disk-brakes/#findComment-349786 Share on other sites More sharing options...
41chevy Posted October 25, 2016 Share Posted October 25, 2016 5 hours ago, Vladislav said: The axle with the brakes of the style you describes is fitted in my DMM Mack. And it's a standart factory equipment. Discs with hydraulic calipers. And damn air/juice mixed setup on the left framerail to activate it. I have no knowledge of how it actually works though. The truck is not running. Explaination of operation from my DM disk brake supplement (it's a pdf type file I can't transfer here) Air-over-hydraulic brake systems contain an air-over-hydraulic power cylinder. This cylinder has both an air cylinder and a hydraulic cylinder inside, which work in tandem with each other. The air and hydraulic cylinders each contain a piston and common rod. The air cylinder's piston is a larger diameter than the hydraulic cylinder's piston. This results in greater hydraulic pressure being released during normal breaking. When the brake pedal is pressed, the valves are opened by the combination cylinder, releasing the atmospheric pressure that builds up when the valves are closed. During hard braking, the combination cylinder causes greater valve movement. This results in the valve releasing more air into the air-over-hydraulic power cylinder, allowing for faster braking. 1 Quote "OPERTUNITY IS MISSED BY MOST PEOPLE BECAUSE IT IS DRESSED IN OVERALLS AND LOOKS LIKE WORK" Thomas Edison “Life’s journey is not to arrive at the grave safely, in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘Holy shit, what a ride!’” P.T.CHESHIRE Link to comment https://www.bigmacktrucks.com/topic/47387-front-axle-with-disk-brakes/#findComment-349827 Share on other sites More sharing options...
Vladislav Posted October 26, 2016 Share Posted October 26, 2016 Paul, thank you for posting that. Looking over the setup on the truck I got figured in general how it works. The said above I meant the truck is not running so I had no experience of how those brakes are good or bad on the road. Relating to the common air style. Quote Никогда не бывает слишком много грузовиков! leversole 11.2012 Link to comment https://www.bigmacktrucks.com/topic/47387-front-axle-with-disk-brakes/#findComment-349998 Share on other sites More sharing options...
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