Newbie with M51A2 Dump Truck, need info and hints!

[JohnnyBM931A2]

After a lot of manual reading and forum searching, I figured I should post my conclusions.

I am going to put 22 qts of 14-40w oil in the engine
I am going to put 9 qts of GO 80/90 oil in the transmission
I am going to put 5.25 qts of GO 80/90 oil in the transfer case.
I am replacing both oil filters and all 3 fuel filters.
Primary Fuel filter - Wix 33511
Secondary Fuel Filter (Need 2) - Wix 33512
Oil Filter (Need 2 ) - Wix 51133

Will make sure brake fluid is at level.
Will make sure steering fluid is at level.

I wanted to replace the differential oil but this looks like to much work to do on the lot. I will do this once it is home.

I than will need to drive it 45 miles home via the highway. Wish me luck!

Am I missing anything here?

Don't forget to check or replace the coolant dude

 

[tobyS]

After a lot of manual reading and forum searching, I figured I should post my conclusions.

I am going to put 22 qts of 14-40w oil in the engine
I am going to put 9 qts of GO 80/90 oil in the transmission
I am going to put 5.25 qts of GO 80/90 oil in the transfer case.
I am replacing both oil filters and all 3 fuel filters.
Primary Fuel filter - Wix 33511
Secondary Fuel Filter (Need 2) - Wix 33512
Oil Filter (Need 2 ) - Wix 51133

Will make sure brake fluid is at level.
Will make sure steering fluid is at level.

I wanted to replace the differential oil but this looks like to much work to do on the lot. I will do this once it is home.

I than will need to drive it 45 miles home via the highway. Wish me luck!

Am I missing anything here?

Batteries

 

[JohnnyBM931A2]

Batteries

Certainly worth double checking. However, in the original post he said it starts right up.

 

[srodocker]

Ahh we have a few guys on try side over there. Check out the PNW Info thread and post up where you live and they should chime in sometime.

Even if you drive a civi vehicle over we dont care.

 

[Tototex]

Thanks for all the tips. The batteries seem to be working fine.

I could not find the braking fluid to check it.

I am not 100% sure I found the fuel filters but I think so. I didn't change them.

I changed the engine oil. It was bad. A ton of decent size metal in there. Changed the oil filters as well. I checked the dipstick before changing the oil. It said it was only 4 qts low. Only 2 gallons of oil came out. I found this very strange. It took 5.5 gallons to fill it back up which is normal. Weird.

I changed the transmission oil, it looked new.

I drove it around the block. Thing practically dies when I shift to 4th gear. I wonder if I need to let it get going a little faster before I try that.

It seems impossible to take off in 1st gear. By the time I shift to 2nd, it stops... Haha. I've been taking off in 2nd gear. Seems to be doing alright that way.

The engine makes a really loud clanking noise while idling. Sounds like the broken rocker on my car when it went out. The sound goes away when you simply push in the clutch, or rev the engine. Anyone know what this might be?

I got the gauges to work. Everything but the temp and RPM seems functional. I've included a picture of the gauges while idling after the oil change. Air pressure looks low but I think everything else is alright.

All that work aside, she sure is fun to drive! Drove around a residential neighborhood. This thing dont turn on a dime... or a quarter for that matter...

 

[Ferroequinologist]

Hi and welcome!

Which guage is air? If you are only running 30 or less oil pressure that seems a bit low to me. My well worn multi runs 90 cold and 60 hot at idle.

Also, you can't trust the milage and hour meters in any of these trucks. It is a rare thing one or all don't get swapped out at some point in their lives.

As far as parts, you can try Boyce equipment, I think they are west coastish.

Please download or purchase the operator manual for the m39 series trucks. Read it front to back. 6 times. It really helps when something happens on the side of the road and you remember the part in the TM, or at least know how to find it. Don't take this the wrong way but until you do and therefor can find the master cylinder to check the brake fluid, please don't drive it on public streets. These are very rugged trucks but careful care is absolutely required to make them road ready and keep them that way. As was mentioned the brake systems can fail altogether if only one thing in the system fails. It sounds like it was being used in a yard? This should be a good thing as the brakes have been getting exercise. It doesn't mean they are up to the challenge of stopping the truck at 50mph. One other thing you might want to do when you get home is replace all the rubber brake hoses. Why am I such a stickler for brakes? Because picking up my first m35 I plowed through the end wall of a government warehouse due to brake failure and my unfamilurarity with the truck.

I have a dump truck too but it is the next newest model to yours. Good luck looks like a nice truck!

 

[Tototex]

Oil is actually the left gauge. So it is idling at 60-70 after my oil change. Before the oil change it was around 50. The manual says the oil should idle at 15 though.

My air is idling at 35 PSI or so. I can hear some leaks. Tracked one down to the wipers, shut them off. Not sure where the others are coming from. Manual says not to operate vehicle under 65 PSI and normal is 105-120 PSI.

This may indicate issues.

I've been reading the manuals, there are a lot of them and they are all large. I've located the master brake cylinder. Looks like its in a trap door under the drivers foot. I did peak in there the other day.

I'll go out again tomorrow and check the fluid level. I presume this is done at the MBC? Manual does not specify.

I will also track down any air leaks I can and start plugging.

I only have a couple of days to get this home from the lot it is on. So I am doing all I can to ensure it will be a safe trip.

Brakes feel very responsive, not squishy, no funny sounds. I think they will be fine. If they did go out, its a hilly drive, I should be okay rolling uphill to a stop and hitting the hand brake. Else I suppose I would just pull the handbrake in an emergency?

 

[Robo McDuff]

Welcome from a fellow dump owner.

You cannot overestimate the importance of good brakes. If they fail, you have 10 tonnes of dead weight running wild. It will crunch anything or anybody in front of it. The hand brake is a joke. It might keep your truck parked at a not completely straight road, but forget about any stopping power will driving even at very low speeds.

I made the rooky mistake of driving without checking properly but had beginners luck, nothing went wrong till now. Changed all the external lines, now I am planning to go for the individual brake cylinders and changing the system into a dual brake system. Too risky here in busy Europe to keep it single.

writing this from an ipad, so will do the links later.

 

[fasttruck]

Brake master cylinder is under floor in front of driver's seat and accessed through trap door in floor. Military has been using DOT 5 brake fluid for some time. Do not mix DOT 3 and 5 together. Primary fuel filter is under left fender . Do you know that this truck has 2ea electric fuel pumps ? One, near the batteries pumps fuel out of right tank into left tank which is the one the engine runs on. This is controled by a switch on the dash. A second fuel transfer pump is in the left fuel tank and pumps the fuel up to the IP. This has a fuse on it under the top cover which is a frequent source of problems. This pump comes on with the battery switch. Depending on how tight the fuel system is the engine may not run at all or will run poorly if this pump fails. If first pump fails you will be isolated from the fuel in the right tank.

 

[Tototex]

Welcome from a fellow dump owner.

You cannot overestimate the importance of good brakes. If they fail, you have 10 tonnes of dead weight running wild. It will crunch anything or anybody in front of it. The hand brake is a joke. It might keep your truck parked at a not completely straight road, but forget about any stopping power will driving even at very low speeds.

I made the rooky mistake of driving without checking properly but had beginners luck, nothing went wrong till now. Changed all the external lines, now I am planning to go for the individual brake cylinders and changing the system into a dual brake system. Too risky here in busy Europe to keep it single.

writing this from an ipad, so will do the links later.

I would love to see those schematics. Having some redundancy in the brakes is a must!

So, how would one go about parking this thing on a hill? Hand brake wont hole it, just leave it in gear?

 

[Tototex]

Brake master cylinder is under floor in front of driver's seat and accessed through trap door in floor. Military has been using DOT 5 brake fluid for some time. Do not mix DOT 3 and 5 together. Primary fuel filter is under left fender . Do you know that this truck has 2ea electric fuel pumps ? One, near the batteries pumps fuel out of right tank into left tank which is the one the engine runs on. This is controled by a switch on the dash. A second fuel transfer pump is in the left fuel tank and pumps the fuel up to the IP. This has a fuse on it under the top cover which is a frequent source of problems. This pump comes on with the battery switch. Depending on how tight the fuel system is the engine may not run at all or will run poorly if this pump fails. If first pump fails you will be isolated from the fuel in the right tank.

I did not know this. Very good information. The left fuel pump has been changed by someone. It has its own switch on the dash and comes on even if the battery is disengaged. Interestingly enough, I can run the truck with the battery in the OFF position due to that switch. Seems they did not want to run it to the original battery switch.

I am guessing that the Fuel Transfer Switch on the dash is what transfers fuel from the right tank to the left. I should make sure that works as the right tank is topped off.

I just looked up the ways to identify whether the system is DOT3/4 or DOT5. Im hoping its DOT5, will find out soon enough.

 

[Tototex]

Welp, I thoroughly checked everything and was confident that this baby would make the 45 mile drive.

2 Miles down the road cruising at 45 MPH, she threw a rod right through the block. I've now got a 2" by 4" hole in my engine.

She is spending the night on the side of the road tonight and I got a tow truck coming out in the morning.

Looks like I will be hunting for a new motor. Any tips on this appreciated.

I should have known there would be trouble after changing her oil. Some fingernail sized metal chunks came out with the oil.

Edit: I think since this thread has come so far, its time to make a new one!

 

[srodocker]

Is that the multi right? I'll send you a number for brad give him a ring he has some engines.

 

[Peteradventure]

Can anyone tell me where to find the manuals for an M51A2 dump? SN 9623 12111, mfg Kaiser Jeep Corp? I am looking at buying one that looks like its in fairly good shape with 38,000 miles and 800 hours. I am most interested initially in the operators and basin maintenace manuals. If I buy it Ill need more I am sure. Also does anyone know how to tell what year it is from the SN?

Thanks, newbie in the making

 

[wascomatw74]

Sorry double posted

 

[wascomatw74]

Look at the top of the page, right under Steel Soldiers. Sorry the numbers escape me right now . Look for the M39 series ,sub under 5 ton and up. Can't beat free download. great reading .

 

[Peteradventure]

Look at the top of the page, right under Steel Soldiers. Sorry the numbers escape me right now . Look for the M39 series ,sub under 5 ton and up. Can't beat free download. great reading .

Thanks for the links. These are great manuals well written with few typos, though one needs to read them more then once.

Reading the above story it sounds like real problems can occur, I am surprised by the blown engine story though there were some signs. The used auto dealer want $7,500.00 which seems a bit high any thoughts? After reading the materials I plan to run it for a while and make sure everything is within spec. then take it on the road for a test ride. Any suggestions?

 

[Tototex]

Welcome to the Forum Peteradventure.

Here are all of the TMs for this truck.

http://www.steelsoldiers.com/showthread.php?77614-TM-s-for-the-M39-Series-5-ton

I learned a **** of a lot going through what I did. $7500 is a fair price for this truck if it is in good running condition. I have not seen many lower than that and if so, they had some major issues to contend with.

My M51A2 did have some major signs. Leaking oil, chunks in the oil when I changed it. My biggest regret is not test driving it on the Hwy.

So my advice, change the oil if they will let you, check for any debris in the oil when it drains. Color of the oil will let you know if they maintained it well, changed the oil often. I know oil changes are spendy but will give you good information on the truck and likely something you need to do immediately after purchasing it anyway.

Test drive her on a HWY at top speeds for a few miles at least. I only test drove in a suburb and all seemed well.

Also, mine was listed for 7500 as well. I ended up purchasing for $4500. So definitely haggle them.

And to update everyone on my story. I did get around to buying a used engine and getting it installed. Used engine had blown head gaskets. Replaced those. Now I've got her up and running!

Dont hesitate to contact me if you need anything.

 

[ShawnIfert]

I had one years ago. I had a great time with it. I had a m51 with a Mack engine. I got it from an old farmer that had it parked in the barn for years. Have fun with your new truck!!!