06 CM870 450 ISX egr tuneup

[Chamberpains]

What does the the travel of the arm on the VG ring measure. Is it free moving with a slight high pitch metal screech to it (normal)? Does the shaft move up and down at all (signs of wear)

[Rawze]

CM870/air operated turbo only ...
if a person removed the air actuator from the turbo, then cranks the truck, they should be able to easily press the control arm down towards max travel with force of one or 2 finger while engine is running (this should spool up the turbo). It should then gently float back up on its own as you let go of it.

If it stays down, does not float back towards the top most of the way back when u let go of it, hangs up in places, sticks at 100% down position, or is harder to move with engine running, the turbo is toast.

[DDlighttruck]

The link Champerpains provided in Quickserve stated to measure the travel of the actuator arm with shop air regulated to 60 psi

It also said to loosen the actuator mounting bolts, apply 60 psi to the actuator, then remove the bolts and remove the actuator.

So, unless there’s another way, I don’t have a way to hook up shop air to the actuator yet

[Rawze]

(09-29-2019 )DDlighttruck Wrote:  The link Champerpains provided in Quickserve stated to measure the travel of the actuator arm with shop air regulated to 60 psi

It also said to loosen the actuator mounting bolts, apply 60 psi to the actuator, then remove the bolts and remove the actuator.

So, unless there’s another way, I don’t have a way to hook up shop air to the actuator yet

All a person needs is a blo-gun with rubber tip to relieve the spring force when installing it or removing it. 20-25 psi is all it typically takes to relieve most if not all the spring force.

Although it is much easier with air on it, the actuator can also be muscled in place (against its spring force) without any air on it at all. It can also be removed by working it loose with a screw driver (once the bolts + snap-ring on arm are removed). It will pop up about maybe 1/8 inch or so (rough guess) with some force (because it is spring loaded) as it lets go but it does not hurt it. Better to use a bit of shop air and a blo-gun on (while installing or removing) it though if you have access to it.

[DDlighttruck]

(09-29-2019 )Rawze Wrote:  

(09-29-2019 )DDlighttruck Wrote:  The link Champerpains provided in Quickserve stated to measure the travel of the actuator arm with shop air regulated to 60 psi

It also said to loosen the actuator mounting bolts, apply 60 psi to the actuator, then remove the bolts and remove the actuator.

So, unless there’s another way, I don’t have a way to hook up shop air to the actuator yet

All a person needs is a blo-gun with rubber tip to relieve the spring force when installing it or removing it. 20-25 psi is all it typically takes to relieve most if not all the spring force.

Although it is much easier with air on it, the actuator can also be muscled in place (against its spring force) without any air on it at all. It can also be removed by working it loose with a screw driver (once the bolts + snap-ring on arm are removed). It will pop up about maybe 1/8 inch or so (rough guess) with some force (because it is spring loaded) as it lets go but it does not hurt it. Better to use a bit of shop air and a blo-gun on (while installing or removing) it though if you have access to it.

Alright, thanks. I’ll see what I can improvise today

Which is more important to troubleshoot, the turbo or the actuator?

[Rawze]

(09-29-2019 )DDlighttruck Wrote:  Alright, thanks. I’ll see what I can improvise today

Which is more important to troubleshoot, the turbo or the actuator?

the turbo and its arm movement for sure first.

[DDlighttruck]

(09-29-2019 )Chamberpains Wrote:  What does the the travel of the arm on the VG ring measure. Is it free moving with a slight high pitch metal screech to it (normal)? Does the shaft move up and down at all (signs of wear)

   

I have roughly 1/2” of travel. Using a mark and a tape measure. Using a blow gun to feed it air the dial indicator spun too fast for me to count the times it went past 0

The arm on the turbo, you’re asking how far did it travel? It seemed to travel the same distance with the actuator on or off, moving it by hand

That’s probably not precise enough to give you the answers to what you were asking me

[DDlighttruck]

(09-29-2019 )Rawze Wrote:  CM870/air operated turbo only ...
if a person removed the air actuator from the turbo, then cranks the truck, they should be able to easily press the control arm down with one finger while engine is running (this should spool up the turbo). It should then gently float back up on its own to the top position as you let go of it.

If it stays down, does not float back towards the top most of the way back when u let go of it, hangs up in places, sticks at 100% down position, or is harder to move with engine running, the turbo is toast.

      
Top picture is all the way to the top.

Engine running, push all the way to the bottom, let go, that’s where it wants to stop on it’s journey back to the top

So my turbo is scrap, from what you’re saying...

Thanks for taking the time to walk me through this.

[tree98]

(09-29-2019 )DDlighttruck Wrote:  

(09-29-2019 )Chamberpains Wrote:  What does the the travel of the arm on the VG ring measure. Is it free moving with a slight high pitch metal screech to it (normal)? Does the shaft move up and down at all (signs of wear)

I have roughly 1/2” of travel. Using a mark and a tape measure. Using a blow gun to feed it air the dial indicator spun too fast for me to count the times it went past 0

The arm on the turbo, you’re asking how far did it travel? It seemed to travel the same distance with the actuator on or off, moving it by hand

That’s probably not precise enough to give you the answers to what you were asking me

As I mentioned on the first page of this thread, the VGT on an 870 is supposed to move 12mm (real close to your half inch) so if your actuator is moving the full stroke and apparantly it is, you need to make sure the VGT ring on the turbo is also moving full range. It appears as though yours is sticking? Mine was sticking a while back because the truck sat for 5 or 6 weeks, but I was able to free it up by working it back and forth a bit.