CletusLloyd

Hello all, I have a 99 RD688S and the trailer brake lights are not working. All other lights are working fine. Does anyone know where I can test up at the cab for continuity with the trailer wiring plug? The sender seems to be mounted on the firewall by the valve cover is this correct? Any help is greatly appreciated. -Chris

I swapped out the gasket today and found a tear in the old pan gasket in the exact spot of the leak. Not sure how that would have gotten there. Must have been the previous owner which was the state of Arizona prying on it, or maybe re-used a bad one. Not too bad of a job took me most of the day by myself piddling around. Painted the oil pan and cleaned all the bolts and studs until all the threads were like new. Worst part was cleaning all the oil from underneath on the block etc. Thanks for the help!

Thanks JoJo! I already got the kit from PAI with the new gasket and isolators. I will clean all traces of oil from everything then clean surfaces with acetone or similar. My main question was about putting the silicone at the 4 corners (it says nothing about this in the service manual). Anyway I appreciate your reply, I'll post up results when I finish. Probably going to tackle this one by myself tomorrow. Thanks again! Chris

Hey my name is Chris I've been a long time Mack appreciator and fan. A big fan of the R models, offset cabs (I love the unique look of them), super liners, and RD series. I currently own a 99 RD688s dump truck with e7 350 and eaton 10 speed. Older Macks are rare out here in AZ. I'm from the east coast NC where you pretty much see them all the time. Not here. My plans are to add an older R model of RD and use it for end dump and equipment transport for my small gravel business. I don't mind going slow, I appreciate reliability and tough trucks. -Chris L.

Hello all, This is my first Mack Truck (RD688s 10 wheel dumper) and I absolutely love it but please forgive my ignorance. My mechanical skills and tools are fairly advanced but I have not worked on much heavy diesel, and never anything Mack. It has 9k hours and 235k miles on the E7350 and Eaton 10speed trans. I've had it for a year and put about 6k miles on it for my small rock business. It recently developed a small oil leak at the back of the pan, I hit it with the hot pressure washer and got it clean then drove it for a day, got under it and observed the oil just slightly seeping from between the pan gasket and block/flywheel cover interface. The isolators are pretty well shot around the area in question. My question is how likely it this to be the silastic seal between the block and flywheel cover? That would be a real bitch of a job and I just don't know if I could tackle that one myself. I bought a new pan gasket and isolators from PAI and planned to change the oil pan gasket in the next few days. Should I put permatex ultra black silicone on these interfaces (as well as the front cover interfaces) before I install the rubber gasket? I have read both to put silicone or it will leak, as well as just clean the surfaces extremely well and install. The E-tech service manual doesn't mention anything about silicone for this application. Looking for advice from guys with real world experience. Thank you for any help, it is greatly appreciated!

Hey everyone, I'm in search of a RD688s dump truck. I'm located in AZ but will fly out for a good truck and pretty much prepared for that at this point. I'm looking for steel bed, a/c intact (it gets hot here), engine brake, and hopefully runs excellent because I'll have to drive it home. Lower miles would be great and minimum or no frame rust (no rust jacking). Please let met know if you'd like to sell your truck, I'd rather buy from an individual than an auction or a dealer. I'm not a low baller. Thanks for looking!