Can the valve seals be replace without removing the head from the truck? Remove rocker arms and rotate engine to TDC for each cylinder and do them one at a time?

Sounds possible, maybe put some air in injector hole to keep valves up. Done it on gassers many times. Go thought firing order.

I'd suggest to bring each set of pistons to top dead center, way to easy to drop a valve using the air pressure trick.  because there are running mates, you can do them in sets, ie, 1&6, 2&5 and 3&4.

Sounds possible, maybe put some air in injector hole to keep valves up. Done it on gassers many times. Go thought firing order.

But that would mean removing the injectors.

I would remove the injectors anyway to make SURE the piston is a TDC. I just use a long zip tie in the hole and rotate till she stops coming up

I would remove the injectors anyway to make SURE the piston is a TDC. I just use a long zip tie in the hole and rotate till she stops coming up

But then you're 3/4 the way towards removing the head. But I suppose that at 200k miles it wouldn't hurt to change head, intake and exhaust gaskets.

i have a write up and video in the article section showing how to do the seals (with the head off) but its the same as if the piston was tdc

But that would mean removing the injectors.

Yeah but maybe good time to upgrade or clean them, set of orings and copper washers isn't that much. And like old ford said you'll make sure it's at tdc.

Yeah but maybe good time to upgrade or clean them, set of orings and copper washers isn't that much. And like old ford said you'll make sure it's at tdc.

Only about 15,000 miles on injectors.

i have a write up and video in the article section showing how to do the seals (with the head off) but its the same as if the piston was tdc

I watched your video. Looks like you'd need to have the piston in contact with the valves to do it. Sounds like they were contacting the workbench.

If you want to make sure they are at TDC, then just watch for valve overlap and do its mate.  So if #6 is on valve overlap, you know #1 is just about exact TDC, and plenty close enough for dropping the valves.  Just take your time and it will be easy.  Worst case, you drop a valve in and have to pull the head.

If you want to make sure they are at TDC, then just watch for valve overlap and do its mate.  So if #6 is on valve overlap, you know #1 is just about exact TDC, and plenty close enough for dropping the valves.  Just take your time and it will be easy.  Worst case, you drop a valve in and have to pull the head.

I like to be sure...

 

 

But then you're 3/4 the way towards removing the head. But I suppose that at 200k miles it wouldn't hurt to change head, intake and exhaust gaskets.

Not really. Removing the head is a pita! 

I watched your video. Looks like you'd need to have the piston in contact with the valves to do it. Sounds like they were contacting the workbench.

teah they were when i tapped the keepers loose but it didnt take much, not enough to damage anything, i would be confident doing it with the head on as well, just take your time

Get this tool. Then just run TDC and remove the springs... Then change your valve seals.

Here is one article I just remembered...

http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/26-engine-systems/450-valve-seal-spring-valve-replacement-24v-head

thats the one mike i bought the inexpensive tool from cpp and it worked fine and much less cost

What about some vice grips to hold the valves up and in place? Then piston location would not be an issue.

Vise grip would be in the way of valve retainers that you have to remove.

its either take the head off or get every piston tdc...

I'd really like to pull and inspect my motor and replace the seals. And mabe... gasp... p pump it.

I don't like doing that much stuff in the body. I wish these trucks has swing fenders like the old 60s dodge L series semis.