Working on the M1078 LMTV

[mkcoen]

Took her out for a spin yesterday and to top off the fuel tank. Everything seems to be working perfectly. I'm not sure when I'll get a long shakedown cruise but want to take it out for at least an hour fairly close to home to make sure it's tight. The next big event probably won't be until at least February (Boy Scout Parade, maybe, in Austin) so I'll have plenty of time to get it done.

Just a reminder to stop by the MV of the Month thread. No suggestions on who to vote for but please vote - http://www.steelsoldiers.com/showth...diers-MV-of-the-month-2016-November-VOTE-HERE!

 

[tennmogger]

I took mine to the hills yesterday to scout out some of the fires in East TN and W NC. Coming back I realized there was a vibration that had not been there forever, but maybe had been getting worse. one of those "has this changed? scenarios. There was a vibration along the rear of the cab. Sure enough, this morning a bad cab suspension bag was diagnosed. It allowed the cab to drop enough to make contact somewhere. I had also noticed the air dryer had started spitting more often. The modulator was apparently turning on the compressor to make up for the leaking bag.

Had a nice ride anyway.

 

[ramdough]

I finally made it through the whole thread. Awesome truck. Hopefully I can see it in person one of these days.


Sent from my iPhone using Tapatalk

 

[mkcoen]

I finally made it through the whole thread. Awesome truck. Hopefully I can see it in person one of these days

Thanks! Next event for me in Austin will probably be February at the Boy Scout Parade. Beyond that it'll be in April at the Camp Mabry open house. Or you could come down to San Antonio.

 

[mkcoen]

Things are kind of slow between the holidays but I did take her out for a spin today. Wanted to try out the new steering wheel center cap courtesy of Keith Knight.

 

[TexAndy]

VERY premium. Very swank!

 

[mkcoen]

VERY premium. Very swank!

Thanks! I didn't even have to break out the tool kit.

 

[Another Ahab]

Things are kind of slow between the holidays but I did take her out for a spin today. Wanted to try out the new steering wheel center cap courtesy of Keith Knight.

I had to check them out.

They sound like they're the "big boys" in their market:

http://www.stewartandstevenson.com/​

 

[mkcoen]

I had to check them out.

They sound like they're the "big boys" in their market:

http://www.stewartandstevenson.com/​

They were the original manufacturer of the FMTVs otherwise I doubt I'd have ever paid any attention to them.

 

[oregonfirefighter]

Wow! Made it through all 85 pages! Good reading. Starting up building my M1088A1 I may start a thread. It will be a long build

 

[mkcoen]

Wow! Made it through all 85 pages! Good reading. Starting up building my M1088A1 I may start a thread. It will be a long build

Definitely start a thread. What you run into, especially with a 1088, may be completely different than issues I've had. Specific things like rebuilding or working on the hydraulic pump should go in that thread as well to make it easy for folks to find the info. Reading through 85 pages to find 1 thing can be a bit tedious

 

[engele]

New headlights and antenna on my LMTV. I love it.
The headlight are Euopean Nolden LED headlights.

 

[mkcoen]

Took her out for a spin this afternoon. Temp is about 75° so I wanted to go far enough to get the fan to kick in. Only problem is that the fan never kicked in. Temp gauge hit 210 and kept climbing. Fortunately I was on my way back home so by the time the STOP light came on I was about a block from the house. During the morning PMCS the cold level on the overflow tank was between the lower and upper sight glass (where it's supposed to be) and when I stopped after the trip it was bouncing between the middle and top of the upper glass. When this happened before it was suggested to simply put a switch in to manually kick the fan on. I may wind up doing that but would prefer to figure out why it's not working correctly to begin with.

 

[Another Ahab]

Took her out for a spin this afternoon. When this happened before it was suggested to simply put a switch in to manually kick the fan on. I may wind up doing that but would prefer to figure out why it's not working correctly to begin with.

It's real re-assuring when things work correctly, like they're supposed to. I get it.

It can drive a body nuts when they don't.

 

[tennmogger]

The coolant temperature is sensed by a switch on the right front area of the engine. It's a switch, not a sensor. That switch tells the solenoid valve in the passenger footwall to open or close the air supply to the fan clutch. My truck has a sticking solenoid valve, as have others. I don't recall anyone reporting a bad switch, probably indicating the solenoid is a logical candidate for your failure. Some here have lubed the solenoid piston and got it working again.

There is a lot of info on here from past threads on the same subject.

 

[Pointman0853]

Those headlights are pretty trick, and for $900 US on FleaBay they better be..

Pointman

 

[mkcoen]

The coolant temperature is sensed by a switch on the right front area of the engine. It's a switch, not a sensor. That switch tells the solenoid valve in the passenger footwall to open or close the air supply to the fan clutch. My truck has a sticking solenoid valve, as have others. I don't recall anyone reporting a bad switch, probably indicating the solenoid is a logical candidate for your failure. Some here have lubed the solenoid piston and got it working again.

The Water Temperature Transducer?

Item 10 in graphic.

Or is it the switch that's located on top of the coolant pipe?

 

[tennmogger]

That might be the temperature transducer but it's not the fan switch. Look in front of the engine where one of the hoses attaches and runs forward. Picture attached, at the oval, just below picture center.

This switch can easily be checked with an Ohm meter but I can't remember if it is normally open or normally closed. If NO, then shorting across the wire plug's terminals with engine running should start the fan. If it is NC then unplugging the lead should start the fan. I think it is NC. If neither works , then the solenoid valve is probably the culprit.

Unplugging the solenoid should start the fan. With passenger's foot cover removed, look upper right. Two small black tubes and an electrical pair go to the solenoid. Unplug the connector and the fan should turn on.

The system is "fail-safe" so if the electrical fails the fan turns on and if the air supply drops out, the fan turns on.

 

[Suprman]

I run the truck with the cab open and drain the air tanks to test the fan clutch it will engage when the air drains down and close the tanks and watch it disengage. Dosnt test the sender and solenoid unfortunately though.

 

[mkcoen]

The one on the coolant line was what Keith_J told me to check. I was going to pull it and test in boiling water like a thermostat but your suggestion sounds much easier