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When I bought the 85 RW I found that it had the engine brake, the previous owner didn't know so I figure it has not worked for awhile.  I replaced the brass connectors that go into the block and pump.  Today a guy canceled so I decided to see if I could figure out what is going on with it.  I have power to the governor and I also have power to the switch that is mounted on the shifter.  When I rev up the engine and let off and turn the switch on I hear the relay in the glove box chatter/vibrate but nothing else happens.  I can't tell if I have power yet to the wire on heads. But if I rev up the engine and let off and apply power to heads with a hot jumper wire nothing happens, so I guess I need to replace the solenoids on the heads?  

Nothing in the service manuals but the wire schematic.  I have searched on here but no luck.

Somebody have the Dynatard manual?  

 

Robert

"I reject your reality and substitute my own."

 

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Update I was able to test the wire going to the heads.  When the engine is under power (reved) it has full power 13.6volts, the relay chatter/vibrate and the switch is in the on position.  When the throttle is released and the engine resumes idle speed power goes away and the relay stops chatter/vibrating.

So I guess it is the solenoids under the valve cover.  Any special tools or care that needs to take place to unhook them and replace? 

Robert

"I reject your reality and substitute my own."

 

Take vale covers off and have some one flip the switch on and off don't have to have truck running just have key on.Should be able to see the solenoids moving or not.

Kinda sounds like you might have a short in the wiring some where.

Had some on my 86 the solenoid was working but would not work had to replace the cylinder in the rockers 

  • Like 1

I will see about taking the valve covers off if its more than the solenoids I am not going to fix it.  I would rather have a Jacobs but I am not sure were I would even find one.

How big of deal is it to replace the solenoids and any idea what they cost?

Robert

"I reject your reality and substitute my own."

 

I have one with dyntard and one with jake brak and no difference in braking power.I like the dynatard better because when you are going up a hill slow and need to shift using the jake it is too slow about coming on.The dnytard is as fast as your finger.This may be just because there is something wrong with jake brake.It i adjust right but there may be some dirt in the screen on the solenoids cause i have not taken themoff and looked.

glenn akers

Disconect the wire that comes  to the head from the firewall then determine if you got power on that wire if so you have a short remove the wires one at a time from each head till you find which one or ones are shorted remove that valve cover/s and determine what is shorted!

Edited by fjh

I have power from firewall to head when it is supposed to be powered.

I replaced the brass terminals that go through the head earlier this spring because they were leaking oil.  I guess when I have a little more time I will pop the valve covers off and have a look.  I saw on PAI that they sell the solenoids but not sure what they cost.  I think I will price them and see if it is worth delving deeper.

Thanks for all the reply's, I bought one of the Dynatard manuals of ebay.  It is only 12 or 15 pages I will see about getting it scanned and loaded up if the site works better than when I was doing the other stuff.  It was a real PIA to upload PDFs. 

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Robert

"I reject your reality and substitute my own."

 

Under each rocker there is a bridging piece that push both valves on the inlet or exhaust at the same time 

 

Highly unlikely that all solenoids are crook at the same time grab a multi meter and check the coils you may have to get some emery and clean up the contact a bit to get a good test most likely the connection between the rocker cover and the head is not installed correctly or has no proper connection but test the solenoids first as that will tell the story 

 

 

Simply touch a power wire to the pass thrus on the out side of the head if the sols activate then check the rocker shafts for the plugs as Glenn has mentioned they have been known to pop out!

Note I ussually grab power from the start relay as it is close by!

Edited by fjh
  • Like 1

Had a chance to work on the Superliner today.  Glenn, I see the other set of valves hiding in there.  

Since I had the valve covers off I ran a check on continuity of the brass posts and one was shorted out for some reason.  The solenoids worked fine when I ran a hot lead to them.  After replacing the faulty brass post I now have the dynatard working.  I took it for a test drive and it seems to work fine.  Nothing like stage 3 Jake more like a stage 2., but it should help save the brakes and drums on the old girl since the drums are $325 each. 

I took a video of the testing with engine running and will post a link when I get it uploaded to youtube, for now all I have is pictures.

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20161002_151136_edited.jpg

Robert

"I reject your reality and substitute my own."

 

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