Newbie Questions for a 1962 M55 Gasser

[ThatXJGuy]

So I just picked up my first MV about two weeks ago, so I'm learning quick and one thing I'm not learning is where to find much info on the older trucks specifically about the R6602 like I have and all the original 1962 stuff my truck has like the "triple fail" compressor that I have. I just brought it into the shop today and am going to be starting on it in less than 12 hours now...

So for the Questions:

What brake fluid should I use? The TMs mention some silicone military part number that I have no idea how to look up. I would assume that Dot 3 would be it but assuming gets me bad places sometimes.

Where is the alcohol/methanol inlet for the air system or is there one? Haven't found one yet and I'm not sure there is one.

Are there any motor oils or gear oils that shouldn't be used with one of these (synthetic/non-synthetic, detergent/non, etc.) and are there any that you should always use? I know what weights to use in the engine and axles according to the dashboard but it sure isn't specific about anything else like the transmission or transfercase or what grease to use for the chassis or anything other than military part numbers that I don't understand.

What pressure should the mechanical fuel pump put out? somebody went and added an electric 12v pump at the tank but they still run it through the mechanical and I'd like to test the mechanical pump to possibly see why they did that.


I'm sure there will be more that i'll have after tomorrow but that's all I can think of now. I'll keep searching TMs as well but I don't know what to do when I run into these military part numbers or specialty tools. If they gave a description or something that would be great but so far I haven't found any.

Any info would be greatly appreciated, Thanks in advance!

Mike

 

[mikey]

Dot 5 is silicone. However, you should be sure Dot 5 is what is currently in the truck. You cannot mix Dot 3 and Dot 5 or bad things can happen.

Mikey

 

[ThatXJGuy]

Is there a way to tell what is in the truck? I have no history on the thing, how would I know? And what type of bad things happen? Like brake system deterioration things or loss of brake power things?

 

[Warthog]

By typing "Dot 5 Dot 3" in the Google search at the top of the page will bring you hundreds of threads that have covered the topic.

Since you truck is a 1962 M55, more than likely it will be Dot3. Take a sample out, put it in a glass jar and mix the same amount of new Dot3 with it. Shake it up and let it sit overnight. If it doesn't separate the it is Dot3

 

[hndrsonj]

Do you have any of the early gasser manuals? Most of the stuff will be the same as the newer trucks but I would definately buy the gas engine manual. Try Portrayal Press.

 

[armytruck63]

You have a very neat truck and I'm glad you are not talking about re-powering it. I would use heavy-duty 30W oil in the engine. Maybe someone else will chime in here, but I think shell Rotella 30W would be excellent in your engine. Even though the Rotella is made for diesels, you have a heavy duty gas engine on your hands and the Rotella should work great in it.

The second fuel pump is a trick to overcome vapor-lock. Maybe the previous owner had problems with this.

Transmission and transfer case work fine with GL-1 90W gear oil. You can get this older formula at auto parts stores in 5-gallon pails. Grease is just heavy duty wheel bearing-chassis lube grease.

The R6602 "knows what to do with gas", but it is a torque monster.

 

[mikey]

You can extract a little brake fluid from the truck and put a few drops in a cup of water. If it's dot 3 it will dissipate, if it's dot 5 it will form little balls.

If you combine dot3 and dot5 it gels up and can lead to brake failure and / or reduced braking.

Here is a thread you should read regarding brake fluid:

http://www.steelsoldiers.com/showth...ow-to-tell-which-kind-you-have-DOT-3-or-DOT-5

Mikey

 

[RodUSMC1962]

I have a 1952 Studebaker gas m-35 that has vapor lock problems starting when hot and have never heard of second fuel pump, do you think it`s worth a try?

 

[armytruck63]

Yes. I have a friend with two WWII Dodges who has vapor lock troubles with both of them. He put electric fuel pumps on both of them. He only flips on the pump when starting or if the truck starts to stumble with vapor lock - usually in warm or hot weather or hot start like you describe. You may have to use a fuel pressure regulator set to about 4 PSI if the electric pump overwhelms the system.

 

[jatonka]

TM9-8028 is M39 series 5 Ton trucks including gas powered on my website in 5 Ton manuals section under M39 or M54 series. You will need to rebuild the mechanical fuel pump as the ethanol gasoline has ruined the diaphram. Then and Now Auto in Weymouth, Mass. is the best and easiest to order kits from. I have some R6602 parts, new and used. Good luck, JT out

 

[ThatXJGuy]

Thank you all for the replies and input, I ended up doing some googling about the brake fluid testing and found exactly what you guys just said so thanks for that, I got some out, dropped a few drops in a cup of water and it did exactly what DOT 3 does so I added DOT 3 as I bled, however, what came out ended up separating in the container it went in to and had lots of nasty black chunks... No bueno... but after a lot of flushing I got every bleeder to flow pretty new yellow DOT 3 and... Still had no pedal response... So I don't know exactly what is going on but from my knowledge of regular pickup and jeep hydraulic brakes, that points to a master cylinder to me. One thing I know is the airpack for the brakes is not the original, it looks newer than most of the mud on the underbody, no joke. It is all pretty green when the rest of the truck is yellow and rust. Sooo, somebody has been playing with the brakes and I really wish I knew who it was so I could call them up and talk to them. Are there any other things that could cause no pedal response other than a master cylinder? I did notice (or my buddy helping me first noticed) that it didn't really spurt out when the pedal was pressed down like a normal truck would or always have in my experience. It just flowed smooth and even flowed when the pedal was not being touched which made it basically possible to gravity bleed the system. Does the air system need to be pressurized for the brakes to work? Or at least the first time? It did take a lot more brake fluid than it put out over the course of the day so a lot of air was replaced with fluid somewhere. We had air coming out the bleeders and coming back up the funnel on the top of the master cylinder for the first 20 minutes.

On another note, there are two air hoses that come off of the top of the transmission by the shifter, they run to the transfercase front output housing. A) why? What does the gear position of the transmission decide whether you have front wheel drive or am I reading that all wrong? B) what is the little fitting between the two lines that at this point goes nowhere? Something in that vicinity hisses very loudly in reverse, second, and fourth gear (the top three). I haven't been able to locate the exact place the air is coming from but it's a LOT of air, and it changes tone if you will, as something rotates as if the air was pointing at a rotating part. I'll investigate that more on Monday and see if I can't find out where it is coming from exactly but any knowledge on any of those things would be awesome.

Let's see what other questions did I have today... I really should write things down... OH! The air compressor! It has two lines leaving the top of it, one smaller one that goes to what I believe is an air governor on the upper firewall, and the other larger one goes straight to the air pack. Where does that compressor take in its air and are both lines leaving the top at high pressure? I really need to take more pictures as they may come in handy in describing these things.

In response to your other comments, no I do not have any gasser manuals, i have been stumped at finding any on here as they all seem to say multifuel on the top page and none seem to refer to the M-55, just the M-55a2.
As far as the fuel pump goes, that sounds about right, I was wondering if they added it because the mechanical pump quit or just using it as a lift pump or what. I have always used the pump when starting and running it but i'll have to try leaving it off and see if the mechanical pump will do the job.

 

[hndrsonj]

Did you start by bleeding the air-pack?

 

[hndrsonj]

http://www.steelsoldiers.com/showthread.php?3229-Deuce-Power-Bleeder-R4x4-Style Build one of these. It will save you a lot of heartache. For the manual John referenced, Google Jatonka TM to find the TM9-8028 (under the 5 ton section).

 

[ThatXJGuy]

TM9-8028 is M39 series 5 Ton trucks including gas powered on my website in 5 Ton manuals section under M39 or M54 series. You will need to rebuild the mechanical fuel pump as the ethanol gasoline has ruined the diaphram. Then and Now Auto in Weymouth, Mass. is the best and easiest to order kits from. I have some R6602 parts, new and used. Good luck, JT out

How long has it been now that they have been putting ethanol in the fuel? Because I might have gotten lucky. This truck has been sitting for quite some time, and I have been putting ethanol free fuel in it since I got it.

 

[ThatXJGuy]

Did you start by bleeding the air-pack?

I did not know how to do that separately, but now that you mention it I think I remember seeing that in a TM somewhere, I just downloaded jatonka's TM9-8028 and will be looking through it over the weekend so I can go back on monday with more knowledge. And on the power bleeder thing, I actually have a power bleeder for regular vehicles and all I need to do is build an adapter for it to go on the MC cap which I believe is 1/8" pipe thread am I right? On monday Ill try again and see if I can't get some brakes! I also need to pull off the cable for the E-brake and try to soak it and get it to break free again, its so stuck I was worried I'd rip the whole assembly out of the floor when I tried to pull it up today. The handle mechanism and lever on the brake end are free and movable but that cable isn't going anywhere... Thank you guys so much for the help.

 

[5tonman1971]

The hissing you hear in reverse is normal that means the shuttle valve for the transfer case to engage the front axle is not gummed up. When the front axle is engaged that hiss should not be present in reverse.

Did you bleed the air pack? You should still have manual braking with no air. The air replaces the vaccum booster in an automotive application.

I would replace the master cylinder or at least rebuild it for safety.

 

[ThatXJGuy]

The hissing never goes away I don't think, and two days ago I couldn't get the front axle to engage, I almost got stuck on flat ground with my two right rear tires sitting on a sheet of ice. Of course I don't know if my air system was up to pressure at that time, I had just unloaded it off of the trailer hauling it to the shop. I did think that the front axle was engaged when I first got the truck. Im not sure though.

And that's what I understood about the air, that the brakes should still work without air, it would just be hard. I didn't bleed the air pack separately though so I'll try that on Monday.

 

[ThatXJGuy]

I got the brakes working, bled the master and air pack and they worked like a charm for about 5 seconds till I blew a steel line on the middle axle, 4 brake lines later they will lock up all 6 on the snow and lock up the rears on the pavement (no weight of course, not even a bed).

As far as the hissing, I think I should have called it a roar, it empties the air system before I can get it backed out of the shop. Im sure it's not normal. Where is the middle line that faces up supposed to go? Right now there is just a fitting facing upwards between the other two. Although I don't think it's all of the leak, it sounds like somewhere below on the passenger side. It's a big big air flow. Also, the transfercase does not seem to engage the front axle and it makes a buzzing/grinding noise as you back up like a lot of reverse gears but it does seem a little loud but then again so is everything else about the truck. The two other lines to the transfercase front output housing from the transmission seem to be in good shape.

 

[vtdeucedriver]

It sounds like your shuttle valve is not working proper. You are correct as it will sound like its under the passenger seat. You can pull the center panels in the cab to access it and see if you can get it freed up. You can attempt it with some hyd jack oil in the system.

As for your brakes, don't get a fuzzy feeling just yet. Those airpacks do not like to sit for long periods of time. You will find either a small square plug or a Hex plug at the back of the airpack. Open that and make sure there is no water. You might get lucky but plan on changing that airpack when your brakes start to drag.

 

[ThatXJGuy]

I'll do some looking in the TMs but I don't know exactly where or what to free up. And where do you add oil to the system? I have a lot of TM to read but I don't know hardly anything about the air system as far as where the pump takes in air or where you can add oil or methanol to the system.

As far as the brake air pack goes, it looks newer than the mud on the bottom of the truck, and it doesn't have any on it itself. I think/or i'm sure that the air pack has been replaced since this thing has seen the road or at least since it's really been used. It may have been replaced after it was driven the last time and that's why it was completely empty and took so much fluid to fill. I'll pull the plug and check but if the inside is as clean as the outside, that airpack has never been used.