m1009 vacuum pump test

[84cucv1ton]

got 25 psi and got like 6 psi at the regulator its called i think. the thing on the side of the injection pump. truck shifts real hard.

so those are good. must be the modulator? thanks

 

[84cucv1ton]

anyone? like to fix this today

 

[SmokeyDod]

Is the vac line plugged in to the mod valve on side of transmission?

 

[84cucv1ton]

the pump from the back of the motor is in the top, bottom is the small piece of hose right to the small metal pipe..

 

[SmokeyDod]

The vac line (rubber hose) runs from the pump on back of engine & goes to metal line that goes to reg valve on side of Inj pump then goes down to mod valve on side of transmission. If hose is rotten anywhere and no vac is going to mod valve, your trans will shift only at higher speeds and very hard. Just make sure you rubber lines are in good shape. A way to ck is to pull hose off of mod valve and while engine running put your finger over end and see if you feel any suction. If not most likely there's a break in your vacc hose line somewhere.

 

[84cucv1ton]

thanks all done. new hose. the reg on the side of the injections pump is forward. new modulator. got the atf and filter changed. why its was off put a drain plug in the pan. all good shifts perfect

 

[CUCV85]

thanks all done. new hose. the reg on the side of the injections pump is forward. new modulator. got the atf and filter changed. why its was off put a drain plug in the pan. all good shifts perfect

Glad to hear it's shifting good for you. Now that the Vacuum lines are tight if you wanted it to shift even quicker - rotate the Vacuum Regulator Valve on top of the injection pump back toward the cab and you can back that brass screw out (a few turns)
at Transmission Modulator Valve. The Stock one does not have the screw.
I would not suggest doing this Modification to shift points if you are off roading and towing!

 

[84cucv1ton]

just looked. no screw in mine. i will get one from jegs, its like 20 bucks or so. i thought towards the cab makes it shift in higher rpm? in second at about 25. 3 about 36

 

[CUCV85]

Pro-King Transmission Modulator Valve

Part No. MD-48
TH350/TH350C/TH400; Black/Red Stripe; Small Modulator Replaces Large; 3 Speed;

Brass adjustment screw
Offer Price: $11.99 Advance Auto Parts

Got mine to shift to 2nd at 20mph and 3rd at 30mph But I don't off road hard or tow!
Vacuum Control Valve rotated toward the cab shifts faster, Military had them all the way forward for the hard TRUE shift for max Torque - Off Road and Tow Operations.

 

[84cucv1ton]

ok thanks. good price

 

[airmech3839]

does anyone have pics of the items that need adjusting? am sure I can handle just want to make sure I am adjusting right stuff in the right way. The blazer I am working on shifts into 2nd at 35mph and 3rd at 45mph. Is that too much....it sounds like the engine is screaming at the change.

Tracy

 

[SPECIALTYLC]

The shift point for the blazer is quite a lot higher than the pickups. Different axle ratios.

 

[4bogginchevys]

hope I can chime in...my 1008 shifts to quickly and doesn't like to shift from 3rd to 2nd going up hills unless I slow way down and punch it. When I come down to about 10-15 mph it's still in 3rd and it's hard to get it back to 2nd then too? Makes the truck feel gutless, and is bad for towing aswell, could someone post a pic of the regulator setup on IP? If an adjustment to this will help me of course....Thank you!

 

[HardCorps79]

The green area in the pic is the vacuum modulator on the psgr side of the IP. The white arrow points to the IP. The red arrows show where there are two 3/8" bolts that hold it onto the IP. You can slightly loosen these (recommend a shorty wrench) and rotate the modulator clockwise or counter-clockwise to change the shift points. Be sure you only hand-tighten them back down. The modulator is plastic and will break, especially if it's cold out.

You'll have to ask someone else about using the vac gauge for adjustments as I've always just guessed by how it drives. Currently my M1009 shifts from 1st to 2nd at around 15-25 depending on RPMs and from 2nd to 3rd at around 35-45, likewise.

Good luck and Semper Fi.

 

[mr.travo]

Sorry to raise this from the dead, but what is the diameter of the vacuum hose? I am on my phone so it's hard to find. Thanks!

 

[joshuak]

Sorry to raise this from the dead, but what is the diameter of the vacuum hose? I am on my phone so it's hard to find. Thanks!

Several diameters are used. The TM's would tell you which and where they go.

Check this thread out if you are in pinch.

http://www.steelsoldiers.com/showthread.php?125916-m1009-vacuum-hose

 

[mr.travo]

That was what I needed! Thanks! Ya these smartphones are GREAT to use for mobile searching until you have to wade through pages and pages of TM's. Thank you for the help!!!

Travo

 

[cucvrus]

3/16" rubber hose will work. You need to adapt it down from 3/8" at the vacuum pump. Easy. Any hardware store has the nylon connections. Top hose to transmission bottom to vacuum pump. That had me already. Good Luck.

 

[militarytrucks.com]

When using a vacuum gauge to adjust the valve at the side of the injection pump, I like to set the valve so there is 10 HG of vacuum going to the modulator at idle.

More vacuum = earlier shifts
Less Vacuum = later shifts

Adjusting procedure is in the TM 9-2320-289-34 section 3-46