jaysm35a2 Posted September 11, 2011 Share Posted September 11, 2011 I need some info on what a good choice to put a air brake control vale on a 66' U600. Next to my driver seat as you guys know is the controls , well I have a trailer brake button for my tractor park brakes and for the trailer brake is what looks to be the tractor protection switch for wet roads. Id like to have the right things and im lost as to what to look for or do. OR am I missing something that Mack did. It looks correct (exept the trailer brake button) from the factory.http://cgi.ebay.com/ebaymotors/BENDIX-MV3-801036-15012679-AIR-BRAKE-DASH-CONTROL-VALVE-/230670627018?pt=Motors_Car_Truck_Parts_Accessories&hash=item35b50a70caShould I buy something like this or do something diff. Do they make just the buttons you can buy so I can at least change the Tractor Park brake button back to yellow? Quote Link to comment https://www.bigmacktrucks.com/topic/20543-need-help-finding-a-good-air-brake-control-valve-for-u600/ Share on other sites More sharing options...
rhasler Posted September 11, 2011 Share Posted September 11, 2011 Jay, what the VIN number on your truck? I ask cuz I randomly looked up a '66 U not 10 minutes ago. Quote "Mebbe I'm too ugly and stupid to give up!" Link to comment https://www.bigmacktrucks.com/topic/20543-need-help-finding-a-good-air-brake-control-valve-for-u600/#findComment-85631 Share on other sites More sharing options...
jaysm35a2 Posted September 11, 2011 Author Share Posted September 11, 2011 Id have to go look , I dont remember off my head. Quote Link to comment https://www.bigmacktrucks.com/topic/20543-need-help-finding-a-good-air-brake-control-valve-for-u600/#findComment-85661 Share on other sites More sharing options...
mowerman Posted September 11, 2011 Share Posted September 11, 2011 on that one should be black,,,bendix still carrythem.bob Quote Link to comment https://www.bigmacktrucks.com/topic/20543-need-help-finding-a-good-air-brake-control-valve-for-u600/#findComment-85699 Share on other sites More sharing options...
mowerman Posted September 11, 2011 Share Posted September 11, 2011 we use them on our congears,,they say bendix emergency,,and back in 66,,they did use wet road type switch for trailer,,was before the color coding...and before people were stupid.lol.bob Quote Link to comment https://www.bigmacktrucks.com/topic/20543-need-help-finding-a-good-air-brake-control-valve-for-u600/#findComment-85700 Share on other sites More sharing options...
jaysm35a2 Posted September 12, 2011 Author Share Posted September 12, 2011 Bob , im going ot PM you to pick your brain over that. Im glad that my trucks not all wrong. Id have to say it looks pretty stock in the set up. Quote Link to comment https://www.bigmacktrucks.com/topic/20543-need-help-finding-a-good-air-brake-control-valve-for-u600/#findComment-85754 Share on other sites More sharing options...
Rob Posted September 12, 2011 Share Posted September 12, 2011 we use them on our congears,,they say bendix emergency,,and back in 66,,they did use wet road type switch for trailer,,was before the color coding...and before people were stupid.lol.bobMy 72 R model has black knobs on the rear wall of the cab; one for tractor brakes, the other for trailer air supply. It does not have front brakes so there is no dry/slippery road selector.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/20543-need-help-finding-a-good-air-brake-control-valve-for-u600/#findComment-85756 Share on other sites More sharing options...
jaysm35a2 Posted September 12, 2011 Author Share Posted September 12, 2011 Yeah the only thing I have is the tractor brake knob and the wet dry road selector and thats the way it was built I think. Quote Link to comment https://www.bigmacktrucks.com/topic/20543-need-help-finding-a-good-air-brake-control-valve-for-u600/#findComment-85763 Share on other sites More sharing options...
Rob Posted September 12, 2011 Share Posted September 12, 2011 Yeah the only thing I have is the tractor brake knob and the wet dry road selector and thats the way it was built I think.If the chassis was built as a tractor, it should have the normal/emergency valve also. If it was built as a straight truck, it could, or could not have the normal/emergency valve. They were optional.This is called the tractor protection valve.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/20543-need-help-finding-a-good-air-brake-control-valve-for-u600/#findComment-85764 Share on other sites More sharing options...
jaysm35a2 Posted September 12, 2011 Author Share Posted September 12, 2011 The build sheets show it as a tractor, I have the tractor brake , then the protection valve. The protection valve acts as the trailer brake knob... Quote Link to comment https://www.bigmacktrucks.com/topic/20543-need-help-finding-a-good-air-brake-control-valve-for-u600/#findComment-85802 Share on other sites More sharing options...
Rob Posted September 12, 2011 Share Posted September 12, 2011 The build sheets show it as a tractor, I have the tractor brake , then the protection valve. The protection valve acts as the trailer brake knob...This is true. However the tractor protection valve also charges the air tank on the trailer. If you have two air lines for connect to a trailer, one of them, (red in color nowadays) will charge with air from the tractor as soon as the tractor protection valve is actuated from "emergency", to the "normal" position. If there is a trailer attached and the lines connected, this line charges the air tank for the brakes on the trailer. The other line at this time only supplies air to the trailer when you depress the foot brake. This line at this time becomes charged with air going to a relay valve on the trailer applying air from the trailer tank to the brake chambers. When you let off the brake pedal, the charged air line from the application of brakes, (blue line) exhaust under the truck, and the relay valve on the trailer exhaust the line pressure that was built up to apply the brakes.The tractor protection valve is there in it's form to disconnect the trailer air supply in the case of a massive air leakage on the trailer, or the interconnecting hoses.RobRob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/20543-need-help-finding-a-good-air-brake-control-valve-for-u600/#findComment-85809 Share on other sites More sharing options...
mowerman Posted September 12, 2011 Share Posted September 12, 2011 This is true. However the tractor protection valve also charges the air tank on the trailer. If you have two air lines for connect to a trailer, one of them, (red in color nowadays) will charge with air from the tractor as soon as the tractor protection valve is actuated from "emergency", to the "normal" position. If there is a trailer attached and the lines connected, this line charges the air tank for the brakes on the trailer. The other line at this time only supplies air to the trailer when you depress the foot brake. This line at this time becomes charged with air going to a relay valve on the trailer applying air from the trailer tank to the brake chambers. When you let off the brake pedal, the charged air line from the application of brakes, (blue line) exhaust under the truck, and the relay valve on the trailer exhaust the line pressure that was built up to apply the brakes.The tractor protection valve is there in it's form to disconnect the trailer air supply in the case of a massive air leakage on the trailer, or the interconnecting hoses.RobRobi thinki what were trying to figure out is that toggle type valve the same part no,except for the nameplate,,both trailer valve,,and slippery road,,im thinking,,,you can interchange them,,,but im thinkin thier probably obsolete anyway,less someone has some n.o.s. somewheres,,rite?..bob Quote Link to comment https://www.bigmacktrucks.com/topic/20543-need-help-finding-a-good-air-brake-control-valve-for-u600/#findComment-85825 Share on other sites More sharing options...
Rob Posted September 13, 2011 Share Posted September 13, 2011 The "flipper" valves are still readily available through Bendix. Early versions used the "flipper" valve for the tractor protection and I think it was 1966 the button with 40psi pressure release was mandated.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/20543-need-help-finding-a-good-air-brake-control-valve-for-u600/#findComment-85868 Share on other sites More sharing options...
jaysm35a2 Posted September 13, 2011 Author Share Posted September 13, 2011 I understand how air brakes work.I will take a picture for you guys tomorrow to explain the thing more. The " flipper valve" is the wet dry valve just like the ones on top the dash of the later R models and is labled the same. Quote Link to comment https://www.bigmacktrucks.com/topic/20543-need-help-finding-a-good-air-brake-control-valve-for-u600/#findComment-85870 Share on other sites More sharing options...
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