Deere Mack Posted May 26, 2015 Share Posted May 26, 2015 Hello everyone, hope all is well. I've been working the 79 RD685S pretty hard lately and she's a real joy to drive until we find a good hill to climb. I know this is no race truck but I want to upgrade something, anything to help with the hill climbs. My turbo has a little oil blow by, would this make it weak? I really feel like something's off and need to figure it out, got a lot of dirt to haul this summer. Thanks! 2 Quote Link to comment https://www.bigmacktrucks.com/topic/40196-tri-axle-dump-endt-675-needs-a-boost/ Share on other sites More sharing options...
Popular Post j hancock Posted May 26, 2015 Popular Post Share Posted May 26, 2015 Turbo may be getting tired. Check the shaft for movement. Other than rotational movement, movement is bad. Any blade damage? Put a boost gauge on it to see what it is pumping up to. Might have a leak in the system and loosing boost.The 675 is bulldog grunt not greyhound fast. 3 Quote JimIt doesn't cost anything to pay attention. Link to comment https://www.bigmacktrucks.com/topic/40196-tri-axle-dump-endt-675-needs-a-boost/#findComment-291319 Share on other sites More sharing options...
Deere Mack Posted May 27, 2015 Author Share Posted May 27, 2015 Turbo may be getting tired. Check the shaft for movement. Other than rotational movement, movement is bad. Any blade damage? Put a boost gauge on it to see what it is pumping up to. Might have a leak in the system and loosing boost.The 675 is bulldog grunt not greyhound fast.Thanks Jim, thats just it, I loosing grunt on them hills...lol....I'm about to put a gauge on it to check boost pressure. I have the S3B087 turbo, I've been told boost with a load on a good hill should be around 18-22 psi. Sound correct? I've got a plug in my manifold circled in the pic below, would this be a good place to istall the gauge? Quote Link to comment https://www.bigmacktrucks.com/topic/40196-tri-axle-dump-endt-675-needs-a-boost/#findComment-291374 Share on other sites More sharing options...
j hancock Posted May 27, 2015 Share Posted May 27, 2015 That spot will be ok on the manifold. OEM boost psi spec was 14.8-19.4 Quote JimIt doesn't cost anything to pay attention. Link to comment https://www.bigmacktrucks.com/topic/40196-tri-axle-dump-endt-675-needs-a-boost/#findComment-291390 Share on other sites More sharing options...
Deere Mack Posted May 29, 2015 Author Share Posted May 29, 2015 Discovered some slack in the turbo and removed it. It shaked like a baby rattle when it was off. Took turbo, pump and injectors to local shop. I want it right! It's exciting to know I haven't seen the ole girls full potential.Thanks for your help Jim! Quote Link to comment https://www.bigmacktrucks.com/topic/40196-tri-axle-dump-endt-675-needs-a-boost/#findComment-291656 Share on other sites More sharing options...
br549 Posted May 29, 2015 Share Posted May 29, 2015 If low on turbo pressure check the intake manifold, that old steel type intake manifold was bad about cracking in the seam where the top half and bottom went together. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/40196-tri-axle-dump-endt-675-needs-a-boost/#findComment-291657 Share on other sites More sharing options...
Timmyb Posted May 30, 2015 Share Posted May 30, 2015 Would like to hear the end results. Always a good feeling when things run like they should! Quote Link to comment https://www.bigmacktrucks.com/topic/40196-tri-axle-dump-endt-675-needs-a-boost/#findComment-291718 Share on other sites More sharing options...
Deere Mack Posted June 11, 2015 Author Share Posted June 11, 2015 Picked up my newly rebuilt pump and a new turbo today. The turbo was completely shot beyond a rebuild and pump was in very bad shape. Turned the pump up a little. Shouldn't feel like the same truck. I'm very suprised at how well it run with those problems. Should have it back together by Sat or Monday. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/40196-tri-axle-dump-endt-675-needs-a-boost/#findComment-292908 Share on other sites More sharing options...
Timmyb Posted June 13, 2015 Share Posted June 13, 2015 Sounds like you got your moneys worth out of that turbo!Should pull really well now, hopefully. Quote Link to comment https://www.bigmacktrucks.com/topic/40196-tri-axle-dump-endt-675-needs-a-boost/#findComment-293175 Share on other sites More sharing options...
Deere Mack Posted June 22, 2015 Author Share Posted June 22, 2015 Happy Fathers day to all the dads!I've been working on my throtle linkage problems and I've got a question.When I adjust my linkage out enough to get full throttle I have trouble with a high idle because the linkage is hitting the firewall and not falling back enought for idle position. Is it supposed to do this or can i trim the linkage to where it will miss the fire wall? Quote Link to comment https://www.bigmacktrucks.com/topic/40196-tri-axle-dump-endt-675-needs-a-boost/#findComment-294218 Share on other sites More sharing options...
Deere Mack Posted June 23, 2015 Author Share Posted June 23, 2015 Happy Fathers day to all the dads!I've been working on my throtle linkage problems and I've got a question.When I adjust my linkage out enough to get full throttle I have trouble with a high idle because the linkage is hitting the firewall and not falling back enought for idle position. Is it supposed to do this or can i trim the linkage to where it will miss the fire wall?Allow me to answer my own question in hopes it helps some poor sap in the future.You can cut this linkage, but you will shorten the push length and it will have to be gained back at the throttle linkage wich put me back at square one. I'm not liking the way my throttle linkage is set up! If anyone has got a pic of the way there's is set up I'd appreciate it. I'll probably re-fab this one and try to make it better, need some ideas though. Thanks Quote Link to comment https://www.bigmacktrucks.com/topic/40196-tri-axle-dump-endt-675-needs-a-boost/#findComment-294382 Share on other sites More sharing options...
85snowdog Posted June 23, 2015 Share Posted June 23, 2015 Sorry I didn't see this earlier. It would have saved you some grief.The dirty, oily linkage is on my 237. keeping everything well oiled is what has kept it good for 30 years of being in salt.The cleaner linkage is off a 350 4V . It appears to be the same, and a lot easier to get close pics.I think this will shed some light on your troubles. If you want any other pics, or from a different direction, let me knowDon't let the spring in the 350 pics confuse you. Its not factory. I find I have a lot nicer pedal with 2 long springs (one there,one on the pump), instead of the 2 factory springs . 1 Quote Keith Link to comment https://www.bigmacktrucks.com/topic/40196-tri-axle-dump-endt-675-needs-a-boost/#findComment-294398 Share on other sites More sharing options...
rick harper Posted June 23, 2015 Share Posted June 23, 2015 Its only 237HP and 906Lb.Ft. torque. What type of weight are you trying to haul and what percent of grades are you trying to climb. The little 237 might be doing all she can. Quote Link to comment https://www.bigmacktrucks.com/topic/40196-tri-axle-dump-endt-675-needs-a-boost/#findComment-294405 Share on other sites More sharing options...
Timmyb Posted June 24, 2015 Share Posted June 24, 2015 I wish I could help ya, but my accelerator pedal is on the right side (yours being left/wrong side). Are there any bushes or linkages that are worn? Quote Link to comment https://www.bigmacktrucks.com/topic/40196-tri-axle-dump-endt-675-needs-a-boost/#findComment-294489 Share on other sites More sharing options...
Deere Mack Posted June 24, 2015 Author Share Posted June 24, 2015 Sorry I didn't see this earlier. It would have saved you some grief.The dirty, oily linkage is on my 237. keeping everything well oiled is what has kept it good for 30 years of being in salt.The cleaner linkage is off a 350 4V . It appears to be the same, and a lot easier to get close pics.I think this will shed some light on your troubles. If you want any other pics, or from a different direction, let me knowDon't let the spring in the 350 pics confuse you. Its not factory. I find I have a lot nicer pedal with 2 long springs (one there,one on the pump), instead of the 2 factory springs .Image 6.jpgImage 7.jpgImage 8.jpgImage 9.jpgThanks for the photos! That helps shine a light on things. It's hard to figure something out when it wasn't right to begin with. Quote Link to comment https://www.bigmacktrucks.com/topic/40196-tri-axle-dump-endt-675-needs-a-boost/#findComment-294498 Share on other sites More sharing options...
Deere Mack Posted June 24, 2015 Author Share Posted June 24, 2015 Its only 237HP and 906Lb.Ft. torque. What type of weight are you trying to haul and what percent of grades are you trying to climb. The little 237 might be doing all she can.Rick, since I've gotten the new turbo and pump, I'm satisfied with her performance. I know what I got, I just needed it be performing at her best! The 237 was later installed before I bought it. They did a good job but the throttle linkage wasn't up to par, I've about got it figured out though. Quote Link to comment https://www.bigmacktrucks.com/topic/40196-tri-axle-dump-endt-675-needs-a-boost/#findComment-294499 Share on other sites More sharing options...
Deere Mack Posted June 24, 2015 Author Share Posted June 24, 2015 I wish I could help ya, but my accelerator pedal is on the right side (yours being left/wrong side). Are there any bushes or linkages that are worn?They have some wear but I beleive my biggest problem is it wasn't installed correctly. Think I'm getting some where with it now, thanks! Quote Link to comment https://www.bigmacktrucks.com/topic/40196-tri-axle-dump-endt-675-needs-a-boost/#findComment-294500 Share on other sites More sharing options...
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