Installing PacBrake

[Rams-n-Hogs]

I am new to this site and I would like to say it is a great site. Tons of useful info. It's giving me lots of good ideas. I'm getting ready to install a new PacBrake with the HD springs. What is the best way to change the springs safely? I don't want to damage the pistons, or valves. How can I tell for sure, (shy of dropping the valve into the cylinder), that the piston is at TDC. I have a service manual, but I didn't find anything on it in there. I am also considering a TST kit in the near future. Gauges will be here this week, also. Any help from you guys is appreciated.

 

[sdaves]

Welcome

I am no Cummins owner (yet), but welcome to the board. I dont have any info about your question (other than our FL rescues have them), but there is a wealth of info here.

 

[RHARVEY]

Welcome Jpeter...

Its fun to hang out here and learn, but be careful there is a little bug that finally bites you. . It called the BOMBinb bug!

I too have been bit a few times and you what I have began to enjoy it

The only thing that it hurts is you wallet>>>>



Pacbrake goes in Saturday,,but no HD springs right now. . thats next and or yes maybe a #11 plate will be under the Christmas tree. . if I can wait that long...



Rick

 

[Joe G.]

Locating approximate TDC

jpeter,



The firing order for a six cylinder inline engine is 153624. As a result of this you can consider 1-6, 5-2, and 3-4 "partners". If you take 1 & 6 for an example. When the rockers are loose on 1 and BOTH are tight on 6 you are close to TDC on 1. In a like manner if the rockers are loose on 6 and tight on 1 then you are close to TDC on 6. It works the same way for 5 & 2 and 3 & 4. This method also works well for locating TDC for adjusting valves. Locating TDC for timing purposes has to be more exact than this method, but for replacing exhaust valve springs and adjusting valves this method works fine.

 

[A Johnson]

Joes right. On that note, when I adjust valves I watch for #2 exhaust valve to be all the way open(rocker lever all the way down) then I know I'm very close to TDC #1 cyl compression. I then dived the dampner in three equal parts and that gives me the TDC for the others. When #5 exhaust is all the way open I'm at TDC #6 compression. Also when I compress the valve spring I let the valve fall down on top the piston before removing the valve collets and roll the engine till I see the valve stem reach the top of its hieght. AJJ

 

[WDaniels]

jpeter,

another way to do your springs and it's the easiest way I've found is to use air to keep your valves from dropping into the cylinders. Remove your injector, put the air fixture into the vacated hole, hook up air to the fixture and presto! The valves stay up. No need to find TDC. (tho it wouldn't hurt in case your air fails) Have to get the fixture tho. Either make one, borrow one(like I do), or buy one.

Hope this helps

WD

 

[Rams-n-Hogs]

Thanks for all the info. That is exactly what I was looking for. Guess I'll be busy Saturday.

 

[BFaoro]

Change

I changed the springs on my 96. I did just like Joe said to do , it worked great. If you are a little spooked hang on to the valve stem and let it go down to the top of the piston slowly till it stops. It will only drop about 1\2 and inch. Good luck !!

 

[jrobinson1]

Welcome jpeter join the fun



I just installed mine last month. A local shop pump shop had an old injector they opened up for air with an air chuck on it. Borrowed it and and injector puller.



Worked great, but geting cyl to top might be easier for a couple reasons. Saves your heart if Air pressure drops. Also pulling the two rear injectors is a @&$%#! Unless you got a puller that fits well under the cowling.



Compressed the spring with a manual twist style. Fits OK on small orig spring but the HD are taller and space is tight. Hand cramps and about and hour of cussing got the rear two done and about 10min a piece for the front cylinders.



I saw a post for making a puller, won't get into it unless you need it. Since the search is down contact me.



james

 

[Rams-n-Hogs]

Again, thanks for all the responses and the help. Couldn't wait until Saturday. Brake and gauges are in and working. No problems with the springs. Other than 5 and 6 being a PITA. But I'm sore today. Been a while since I've done that much wrenching. Now on to the next project.