j hancock Posted May 5, 2018 Share Posted May 5, 2018 On display at Macungie 2014. 1 Quote JimIt doesn't cost anything to pay attention. Link to comment Share on other sites More sharing options...
Melissa Posted January 31, 2022 Share Posted January 31, 2022 Would you be able to point me into the direction of where I can find a service manual for this exact truck? Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted January 31, 2022 Share Posted January 31, 2022 I believe what you are looking for is printed in individual books, I assume you want all you can find, what year is youre RW?.... 613 or 713? what tranny? and rears, probably Mack 92/93 series... I have a lot of books (not for sale) and I can show you the book number, so you can search the Web... jojo Quote Link to comment Share on other sites More sharing options...
Melissa Posted January 31, 2022 Share Posted January 31, 2022 It’s is an 1988 rw613. To be honest I do not know the rest my brother is trying to locate the manual to do some electrical work, I sent him what you sent me so he can give me further info, I appreciate you Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted January 31, 2022 Share Posted January 31, 2022 ok, the engine should be an E-6 4 valve.. The wiring diagrams are basically, R/RD/RW .. very similar if not identical. what electrical issues is he trying to fix.? The truck is pretty simple compared to todays truck's. 1 Quote Link to comment Share on other sites More sharing options...
Melissa Posted January 31, 2022 Share Posted January 31, 2022 I believe the stop light switch. We are trying to determine at what PSI the NO switch should close and give power to the brake lights when brake pedal pressed? Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted January 31, 2022 Share Posted January 31, 2022 There are a lot of smart guys on here, that can help you. If you need to P.M. me, please do and include youre brothers phone number and mabey I can help him.. jojo Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted January 31, 2022 Share Posted January 31, 2022 I think that switch is on the treadle valve under the floor pan.. when the pedal is pressed, it closes the circuit and lights the brake lights. 10 PSI is enough... you can test the circuit by unplugging the terminals and crossing them, brake lights should be lit at this time... jojo 1 Quote Link to comment Share on other sites More sharing options...
Popular Post Joey Mack Posted January 31, 2022 Popular Post Share Posted January 31, 2022 Also, check to see that the piston under the brake pedal isn't sticking, which can allow air to activate the brake light switch. Take it apart if you can, they tend to get corroated because of what fall's off the sole's of your boot's. try to clean the bore and emory cloth the piston, if the rubber boot is junk, replace it, coat the side of the piston with anti seize and put it back together and re-test... jojo 3 Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted January 31, 2022 Share Posted January 31, 2022 here is a sample i found on the web.. Quote Link to comment Share on other sites More sharing options...
Jeff747 Posted February 3, 2022 Share Posted February 3, 2022 Jojo you have been nothing but a huge help. After replacing the brake valve there still seems to be ~35 psi at the stop light switch. The line coming to this switch comes from the tractor protection valve. Do you think the TP valve could be leaking air into the service line? is there a way to diagnose before replacing Jeff Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted February 3, 2022 Share Posted February 3, 2022 mabey pull a line , one at a time from the treadle valve to find which line is feeding the switch port. pul a line, if its not it, hook it back up, and go to the next one.. is the trolly brake valve defective? im sorry but im at a bit of a loss. it would be better if I could see the issue as it happens... jojo 1 Quote Link to comment Share on other sites More sharing options...
D-Day Posted February 3, 2022 Share Posted February 3, 2022 I believe the tractor protection valve would have to be charged before any air pressure could get from one side to the other the brake relay valves for the service brakes are in the system also and are suspect to leak pressure back through the service brake circuit 1 Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted February 3, 2022 Share Posted February 3, 2022 Im just curious how air pressure is present at the air switch, turning the brake lights on.. I wonder if he unhooks each brake valve to find the one that is back feeding air? what do you think, D-Day ? Quote Link to comment Share on other sites More sharing options...
D-Day Posted February 3, 2022 Share Posted February 3, 2022 Yes just pull the big main pressure line and plug it at each valve and build up air check one at a time also the one for the front brakes 1 Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted February 3, 2022 Share Posted February 3, 2022 (edited) Jeff, one thing i'm still not clear on... when all the lines are hooked up, and a little air pressure is present at the switch... have you tried to move the truck, to see if the brakes are dragging. or even just un-hook the service lines on the brake chambers to see if pressure is present? (yellow button pushed in) ? jojo Edited February 3, 2022 by Joey Mack Quote Link to comment Share on other sites More sharing options...
D-Day Posted February 3, 2022 Share Posted February 3, 2022 I have found in the past that with the park brake released (yellow button in) it usually is coming from one of the park brake chambers leaking through to the service side 1 1 Quote Link to comment Share on other sites More sharing options...
Jeff747 Posted February 3, 2022 Share Posted February 3, 2022 27 minutes ago, Joey Mack said: Jeff, one thing i'm still not clear on... when all the lines are hooked up, and a little air pressure is present at the switch... have you tried to move the truck, to see if the brakes are dragging. or even just un-hook the service lines on the brake chambers to see if pressure is present? (yellow button pushed in) ? jojo They don't seem to be dragging at all. I haven't unhooked the lines at the chambers to test this. I do intend on replacing the service chambers Jeff Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted February 3, 2022 Share Posted February 3, 2022 ok.. just curious, jojo Quote Link to comment Share on other sites More sharing options...
Jeff747 Posted February 3, 2022 Share Posted February 3, 2022 26 minutes ago, D-Day said: I have found in the past that with the park brake released (yellow button in) it usually is coming from one of the park brake chambers leaking through to the service side D-day, what would be faulty in this scenario? the park brake chamber? allowing the air to flow through to the service side. Quote Link to comment Share on other sites More sharing options...
Jeff747 Posted February 3, 2022 Share Posted February 3, 2022 49 minutes ago, Joey Mack said: Im just curious how air pressure is present at the air switch, turning the brake lights on.. I wonder if he unhooks each brake valve to find the one that is back feeding air? what do you think, D-Day ? I'll try this method and see if I can back track to what the problem is. Jeff Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted February 3, 2022 Share Posted February 3, 2022 i feel the same as D-Day. some other valve is passing air.. I'm gonna sit back and watch... dont want to put a wrench in the works,,, jojo Quote Link to comment Share on other sites More sharing options...
85snowdog Posted February 3, 2022 Share Posted February 3, 2022 On 1/31/2022 at 6:23 PM, Joey Mack said: Also, check to see that the piston under the brake pedal isn't sticking, which can allow air to activate the brake light switch. Take it apart if you can, they tend to get corroated because of what fall's off the sole's of your boot's. try to clean the bore and emory cloth the piston, if the rubber boot is junk, replace it, coat the side of the piston with anti seize and put it back together and re-test... jojo Jeff, if you haven't checked the piston under the the brake pedal like Jojo mentioned , make sure you take it apart and clean it before you start buying parts. It can just stick on a little and you would never know and seem like its ok. And I think it was said , but check the hand brake( trolly valve ) is not on. I have chased that before. Looking for why brake lights on and hand brake had been applied without me realizing . 2 Quote Keith Link to comment Share on other sites More sharing options...
Popular Post D-Day Posted February 3, 2022 Popular Post Share Posted February 3, 2022 Before you charge the parking brake circuit and release the brakes if you have air on the stop light switch it is getting through one of the other valves and they can be hard to track down if it is a problem only after releasing the park brake the upper brake chamber can leak through the seal separating it from the lower brake chamber and leaking into the service brake system 3 2 Quote Link to comment Share on other sites More sharing options...
Jeff747 Posted February 3, 2022 Share Posted February 3, 2022 15 minutes ago, 85snowdog said: Jeff, if you haven't checked the piston under the the brake pedal like Jojo mentioned , make sure you take it apart and clean it before you start buying parts. It can just stick on a little and you would never know and seem like its ok. And I think it was said , but check the hand brake( trolly valve ) is not on. I have chased that before. Looking for why brake lights on and hand brake had been applied without me realizing . 85, we did do the first part we actually took it all apart and put a new brake valve. In the process we clean the piston and put the antiseize (it moves freely.) I am wondering if the problem is this trolley valve. We will play with this and see if the pressure changes. Thanks! 2 Quote Link to comment Share on other sites More sharing options...
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