RS Disposal Posted April 9 Share Posted April 9 Question #1 Last year when I had to rebuild a head on my 1979 Mack 675 ENTDB engine I notice that the dynatard solenoid wire was all but broken. Ordered a new solenoid. When I removed the old solenoid from the rocker arm I don't remember seeing the steel collar or the "O" ring pictured. Not saying the weren't there, just don't remember The small steel collar I believe is a no brainer as to where it goes on the new solenoid. Question is does the "O" ring just go onto the bottom of the solenoid or the grove that the pencil is pointing to. My thinking is the bottom of the solenoid. Question #2 I am thinking the hydraulic valve lash adjuster on the #4 exhaust valve was damaged, #4 exhaust valve hit the piston. Valve spec won't stay in adjustment. In getting with the dealer, Mack is saying the las adjuster is no longer available even though the rocker arm itself is. Anybody have a suggestion as to where I might be able to get one either new or somewhere somebody might have a blown engine for a used one. Googling hasn't given me any hope. I do have a machine shop. Is this something that can be repaired? Question #3 Being I am really new to heavy truck engines, how does this dynatard actually work? What happens when the solenoid is energized? Quote Link to comment Share on other sites More sharing options...
BOBWhite Posted April 9 Share Posted April 9 This topic seems to have the best explanation: 1 Quote Link to comment Share on other sites More sharing options...
RS Disposal Posted April 9 Author Share Posted April 9 12 minutes ago, BOBWhite said: This topic seems to have the best explanation: WOW thanks I will definitely be going thru that. My search on the site for dynatard engine brake kept coming back "error" try again later. LOL Quote Link to comment Share on other sites More sharing options...
BOBWhite Posted April 9 Share Posted April 9 56 minutes ago, RS Disposal said: WOW thanks I will definitely be going thru that. My search on the site for dynatard engine brake kept coming back "error" try again later. LOL I know google has messed up a lot of in-site searches. Its best to search for topics like this: Someone on here should be able to answer your other two questions 1 Quote Link to comment Share on other sites More sharing options...
Popular Post mechohaulic Posted April 10 Popular Post Share Posted April 10 If you haven't got your answer yet" the steel washer goes under solenoid; o-ring I always soaked in oil then set in to rocker and slowly turned solenoid into rocker. electrical source closed solenoid which allowed oil into exhaust ports eliminating valve lash gap holding exhaust valve open. same concept as jake just different housing set up. 3 Quote Link to comment Share on other sites More sharing options...
RS Disposal Posted April 10 Author Share Posted April 10 1 hour ago, mechohaulic said: If you haven't got your answer yet" the steel washer goes under solenoid; o-ring I always soaked in oil then set in to rocker and slowly turned solenoid into rocker. electrical source closed solenoid which allowed oil into exhaust ports eliminating valve lash gap holding exhaust valve open. same concept as jake just different housing set up. That is what I was thinking on the steel washer and "O" ring. Really disappointed in the "factory" service manual as to alot of things dealing with my truck and engine Quote Link to comment Share on other sites More sharing options...
mechohaulic Posted April 10 Share Posted April 10 13 hours ago, RS Disposal said: That is what I was thinking on the steel washer and "O" ring. Really disappointed in the "factory" service manual as to alot of things dealing with my truck and engine from what i see and hear newer manuals have changed considerably . why make one good manual explaining all when they can make a number of volumes which adds to making more money. I DO understand newer stuff is more complicated in todays world and especially when it comes to the electronics which that alone could constitute a number of books. old man thinking == simple solution ;; do away with the computers and truck electronics . 1 Quote Link to comment Share on other sites More sharing options...
RS Disposal Posted April 10 Author Share Posted April 10 58 minutes ago, mechohaulic said: from what i see and hear newer manuals have changed considerably . why make one good manual explaining all when they can make a number of volumes which adds to making more money. I DO understand newer stuff is more complicated in todays world and especially when it comes to the electronics which that alone could constitute a number of books. old man thinking == simple solution ;; do away with the computers and truck electronics . I do agree it seems that the newer manuals are more one topic rather than multiple topics. I would of thought the factory manual purchased at the same time as the truck, 1979, would of been more inclusive. Thankfully I found this web forum. It has been a very valuable resource. Sometimes real world experience, particularly on older vehicles, is better and more helpful than the manual. I feel alot of manuals are not written by real world experience mechanics 1 Quote Link to comment Share on other sites More sharing options...
mechohaulic Posted April 10 Share Posted April 10 if your old like me; you can recall when a Doctor could "repair "you from head to toes. today's world of complication there are hand doctors/ finger dr's !!= wait a minute aren't those parts connected to each other !! stay on topic now that 'was just an example. maintenance manuals have to follow the trend of complex. all systems : air/fuel and so on are too diversified. one yr it's - - - fuel pump next yr something different. in the day idea was simplify; today manufactures look for ; how can we make it cheaper and charge more. no manual around could accurately cover things. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.