M915 A1 hill climb

[Monkeyboyarmy]

I would guess aneroid valve too. Seen many 915 series trucks with bad pumps. Aneroid valve is on the engine side of the pump so the pump gas to come off to check it out. It is basically adding fuel as the boost comes in.

 

[Artisan]

I just stopped moving forward. I did not watch the trans temp but the trip to the hill was only about 1.5 miles. I was more concerned about backing down the hill at this point than looking at the gauges. I sure temp must have been rising but I don't think I was near hot.

Wait...So you started the truck cold and then did the climb?
Is that what u r saying?

Can you post pics of the trailer and load and truck bro?

 

[quickfarms]

I pulled the selector down to first as I started up the hill and held WOT. the trans, on its own shifted into second (I believe). Then when the hill slowed me the trans shifted ( I believe) into 1st. I had just idled the truck for about 15 minutes prior to starting my 1.5 mile trip to the hill climb. On the way to the hill, I placed the gear selector in 3rd and drove mostly WOT fore the 1.5 mile trip. The temp today got up to about 70

Most Allison's will not shift if you lock in 1st, what you may have felt is the converter locking up. How much did the rpm drop when it shifted?

There is no guarantee that the military did not specify some unusual configuration to the allison.

Do you know if this is the original transmission in the truck?

Has the truck ever been overhauled?

When was the last time the transmission was serviced? What fluid is in it and is it at the correct level?

 

[Csm Davis]

Hey doesn't the fuel pump have a small filter in it like the 250?

 

[kinghomes]

I pulled the Pump and took a close look at the aneroid valve. The balder has pin holes in it. It was damaged at the bottom near where the corrosion had been when I unstuck the valve a year earlier. I remember now thinking "I should change this bladder because it looks weak where it was in contact with the area of corrosion". But, I was behind with a job and pressed on. The truck was doing much better and although I could see a mare, I could not see any holes in the diaphragm. So, if you let your truck sit too long moisture can get in the aneroid valve and stick the valve and damage the bladder.

Thanks for all the help.

 

[rosco]

The first cheapest thing is to change all the filters! Few do it often enough, nor do they realize how important it is. You needed 100% & you didn't have it!