The Stovebolt Site Forums The Parking Lot Big Bolts 1949 4100 Where to start???

Hello all, I am new to the site and have been told that the truck I have is a Big Bolt! It's a 1949 4100. I have not run the vin through the vin buster yet but am planning to shortly. It's a pretty much complete truck and SHOULD be fairly easy to get running. I have read some posts here on some of the things I should do first to get it running. However, I'm looking for some advice. I know running and stopping are first any suggestions on other impartant aspects of getting it going? I'm looking for procedures or recommendations or maybe a check list to cover prior to trying to start a truck that has been sitting in a field for 8 years. Also, is there a spot on the site to find specifications for the 4100? Thanks for any advise.

I'm sure the Big Bolt guys will be in here after dark to talk about the start up.

Maybe this will help with the specs you are looking for.

Peggy M

Peggy,I was looking a that web site when I saw your post. Thanks for the guidance. Looks like that information will come in handy soon.

Congratulations!!! That's a beautiful truck, and you're sure to enjoy the process of getting it running again.

It ran 8 years ago, eh? you're bound to get advice across the spectrum, from "I'd tear the whole thing down before trying to turn it over", to "just throw a battery in her and see what happens!". You'll have to decide what level of "caution" you feel is appropriate, and what your budget (money AND time) allows.

Here's what I WOULD do (take it or leave it!):
Pull all six plugs, and examine them for obvious issues, ie: if one is completely oil-soaked, or fouled. If nothing jumps out, clean 'em up and set them aside. Put a few squirts of (Pick one:) engine oil; Marvel Mystery Oil; Engine tune up treatment in each cylinder. Replace the cleaned plugs.

Pull the top valve cover off. Look for obvious signs of problems with the rocker arms and push rods. If nothing jumps out, liberally squirt engine oil over the rockers and valve stems. Once the engine starts, it takes a minute or two for oil to get up top. Replace the valve cover.

Pop the cover off the distrubutor. See that there's nothing fouling the points. Hit 'em real quick with a touch of sand paper or a points file. Check the rotor and cap for carbon build-up, clean as necessary. Put a drop of oil on the distributor cam while you're at it. Replace the cap. Note that it IS indexed.

BTW, how do the plug wires feel? Are they brittle and stiff, and crackle when you flex them? If so, you're probably headed for a new set. If the local parts store can't run you're truck model, you can get a universal six-cylinder set, but I'd try hard to get the older style, solid-core wires.

Pull the battery and get it replaced, if you don't already have one to use. Clean the battery cables. WHile you're at it, clean the ground strap where it attaches to the frame. Usually, it helps just to loosen the bolt and nut holding it, then tighten them up again.

Did you check to be sure there's oil in the engine? Check the coolant level while you're at it.

It would be nice to confirm that the engine isn't locked up before putting juice to the starter. The EASIEST way, is with a hand starting crank. You probably don't have one (but it's worth checking behind the cab seat!). Some people are able to tension the fan belt with one hand, and pull the fan towards them with the other, and get the engine to turn a little. I've done this maybe twice successfully, out of like 20 attempts. If I don't have a crank, I pull the bottom cover from the flywheel off underneath, and use a pry bar on the flywheel teeth to lever the engine around. If it turns at all, in any direction, it's not locked up. Yay!

Finally, drain the old gas out of the tank. There's a pet-cock on the bottom of the tank I think - you'll want a pair of plyers. Put in 5 gallons of fresh gas. Pull the air filter off, and pour a tiny amount of gas down the carb. throat. Squirt some WD-40 or such on the throttle and choke linkages.

I'd maybe turn it over with the starter a little before turning on the ignition, to start getting oil flowing. Then, pump once or twice on the pedal, pull the choke, and give her a go!

Once she fires, don't over-rev her too hard, just what it takes to keep her going until she's warmed up. I'd put her in gear, move her forward a little, put it in reverse and move her back, and after she's run 10 or 15 minutes, shut her off.

Drain the oil and put in fresh. Drain the coolant and put in fresh. Then run her some more. Other issues will crop up, to be sure. But once it's running, it's a lot easier to stay motivated.

Good luck, and KEEP US POSTED!!! :-)

-Michael

Hi

I would ad, it might be an idea to crack the oil drain plug just enough to see if any water comes out, you usually do not need to pull the plug all the way out.

6 volt systems are more touchy than 12 volt when it comes to the battery cable ends being clean and free of rust and corrosion.

Then with the spark-plugs out for cleaning and no water in the oil. And with a new battery and cleaned battery terminals, I'd hit the starter for about 10 seconds. Then verify that it spins over freely with no knocking noise. You could then hit the starter again to see if you get any oil pressure on the Oil pressure gauge. But no more than about 7 to 10 seconds each time waiting about 30 seconds between each time.

Good luck and happy trucking

This is a good read!
http://www.stovebolt.com/features/feature_stories/bigtrucks/index.htm

It is Okay read for Chevy's, but lacking greatly for GMC.

Why don't you explore here then.
http://www.oldgmctrucks.com/

There's a lot of things that site is lacking in, but it is pretty good for its stated purpose: My comments are written with the '47-'55 1st Series (Advance Design) trucks in mind, but will generally apply to all pre-'60 trucks. It seems that the trucks in the light duty and medium duty ranges really diverge after that.

Maybe someone would be interested in doing a similar write-up for GMCs? I'd be interested in reading that, too.

Here, here! (Is that the right hear?)

We'd love to get more of the GMC details on the site. We are heavy on the Chevy side since that's where the information comes from. I know when we got one of the series tips done, we even ended with something to the affect: That's the Chevy side - anyone want to do the GMC side?

There are a few sites devoted to just GMC so at least there are a few places to go hunt. Having two GMC's ourselves, we have had to hunt ourselves.

BUT ... this looks like the makings of even a good tip on "how do I get started now" ... Let's keep this going and make this a helpful TT. We've lost our Tech Tip writer, and my helper with the Gallery additions. So, once I get the 1/1 Gallery additions done, I can get back into the big pictures.

Michael - thanks for the big write-up on the start-up! That will be a good basis for the TT.

Tim - keep fishing for those GMC helpers!

Cheers,
Peg

Peg,

I'll gladly write up a rough draft of a TT for first start ups, but we should run it by some others before we "publish". For me, start-ups are the most exciting part of the hobby!

Of course, if Wreckin' Ball can't get his truck started, I may have to "recuse" myself! Wreckin', keep us posted - I'm on pins and needles to hear about your progess!

-Michael

Michael,

We have done that before ... drafted a tech tip ... posted it on the server and then solicited input. So, that can work very easily. We have several TTs in there that are a joint effort. AND keeping the thread alive, we can continue to update it, if important changes come along. Tis the beauty of a living document.

Thanks for doing this.

Peg

It will be a little while before I can get it started. There is a problem with getting it from it's place in the field to my work shop. I have been looking for a truck like this for about a year and I happened to mention it to a buddy of mine who said out of the blue "I have one of those trucks," now we just got to get it home. I wll keep you posted. I would love to be a "test subject" for the TT for start ups, just let me know what you need me to do. Thanks guys for posting this great information, now I'm reslly excited to get started.

Wreckin'

That's a good idea. Don (2-ton) King did a clinic at the Kansas City Reunion this past September on "where to start." Don planned on bringing the truck "cold" and John suggested he go ahead and work thru the steps at home first. That way, in the clinic, he could adequately explain each step -- especially if there was a sneaky .5 step that worked its way into the program!! Turned out to be a good clinic.

This ought to fit in nicely, especially for folks new to the hobby (and we are seeing more and more of them). Cool.

Peg

I would add to replace the fuel filter and be prepared to replace the fuel pump while at it. My one ton came to me from just west of you in Garden Plain, KS.

Okay, I also posted this in General Truck talk so that some folks may jump in here and add their two and three cents worth. Don't forget any pictures anyone can share. It's worth a thousand words, ya know. And for dummies like me, pictures are priceless.

Thanks,
Peg

I would do a bit more detective work before I got to deep into the project. I would try and figure out why the truck was parked in the field, where the tires bad? brakes bad? not running good? A truck that sits in the elements for 8 years can develop many issues. I'd drain the oil while I watched for any contaminants in it. I'd also drain the cooling system and see if it is also contaminated. I would take the gas tank out and remove the sending unit and look inside, see if its full of rust or mud or both, then decide on how to make it useable. Then pull the spark plugs and put a shot glass or two into each cylinder. Then pull the valve cover and get an squirt can and get plenty of oil onto the valve stems. Then you can either use the crank or a pry bar on the flywheel and turn it over a good many turns. Then after letting it sit some oil it up again, then have someone help you and watch the rockers and see that the valves are moving up and down correctly. Once its turning over good and is all oiled up get a battery hooked up and have good connections. Do a compression test and see if the numbers indicate if its got issues or if you have enough compression to get it to run. If things inside the valve cover look like its got lots of sludge and crap built up you may want to pull the oil pan and clean the oil pump screen before you try and fire it up so you don't starve the bearings.
Now you have it turning over and are somewhat sure you have enough compression to make it run you can then work on making sure it has spark to the spark plugs. Once I had good spark I would find a long piece of fuel hose and connect it to the input side of the fuel pump and the other end into a gas can with fresh gas in it. I'd crank the motor some with the ignition key off to get cash into the carburetor. Watch to make sure the float doesn't stick and fill the crankcase with gas or flood over the top of the carb. If you get gas to the carb and don't see any leaks and have spark you should be able to turn the key on and it should fire up.
Any engine needs a few things to run, Compression, Spark and Fuel. If you have these then its just a matter of working out the details.
Don

Good advice,Mike! That's the procedure I used when i initially got my T.F.'55 6500 running. But then...after driving on a rough road for less than 1/4-mile, the engine sputtered and died. i already replaced the fuel filter,as well as a new fuel-pump. Hmmm. The last thing checked was the gas tank. I pulled the sending-unit,and couldn't believe the rust scale! I bought a new tank,as well as new fuel lines. Our old engines were designed to operate with zinc in the oil,which these days,are hard to find. I suggest dropping the oil pan,and inspect for metal-shavings,as well as wiping out the sludge build-up. this will keep your oil cleaner,longer. I use Valvoline Z-series racing-oil,the ONLY oil on the market with zinc added. It helps save our solid lifters,and cam-lobes from pre-mature wear,especially during break-in. I also add a pint of ZDD oil additive,at each oil change. Better to be safe than sorry. Welcome to "Stovebolt"! I no longer own a G.M.C.,but THE BEST 3/4-tonner,I ever owned,was a '65, with a 305 V-6,2-speed "Slushbox"(automatic trans.),with a 4:11 posi rear-end. it came with these huge 16" "Camper-Special' tires,and I pulled a FULLY-Loaded semi-out of a ditch with it,and it was 2-wheel drive!! One heck of a truck!! Happy New Year,EVERYONE!

I suggest turning at least a full turn of the crank (maybe two turns of the crank to give a full cycle of the valve train). I have met one 235 that seemed to turn just fine - for maybe 300 degrees - but wouldn't do a full turn. I haven't ripped into it to see the cause but am glad I was turning by hand rather than power to reduce possible damage.

I purchased my '52 after it had been sitting unused/moved in field for more than 25 years or so. Once I got it home, I decided to see if I could get it running (of course the PO said it ran when it was parked). Here is what I did:

1. Pulled plugs and squirted liquid wrench and fogging oil in each cylinder.
2. Drain oil...oops, there wasn't any so I filled her up.
3. Pulled, rebuilt, and reinstalled carb.
4. Assuming fuel pump was no good, I connected carb to fuel can sitting on cab roof via clear tubing. Started a syphon to get fuel flowing to carb.
5. Pulled distributor and rebuilt.
6. Pulled valve cover to manually oil and inspect valve train and clean out all the rodent food scraps.
7. Using a cut-off screw driver blade chuck into my cordless drill motor, I spun the oil pump clockwise to build oil pressure. I continued to spin the pump until I saw oil coming out of the rocker "return" pipe. This verified the oil pump was working and primed the oil system.
8. Reinstalled the distributor and set base timing.
9. Connect 12 volt battery directly to starter and coil with toggle switch on lead to distributor.
10. Broke the engine free with a pry bar. Luckily it "popped" loose fairly easily with no stuck valves.
11. I primed the carb with a bit of fuel.
12. Turned toggle to on and had my soon operate the starter pedal...Vroom, it fired right up immediately and sounded great. All kinds of varmit food came shooting out of exhaust pipe, but it ran.

I did not even bother with the cooling system. Running the engine a few minutes without coolant wont hurt anything (especially if you plan on replacing water pump later anyway...which you should). After I veried it ran, I pulled the engine and tore it down. It was in remarkably good condition, but decided to bore and rebuild properly anyway.

Have fun.

One of the most important items, is to make sure the valves are not stuck, if one turns the engine over w/o checking, risk of breaking rocker arms or bending pushrods, needlessly.

Okay Collective. John finished the draft of this Tech Tip this morning. Take another gander at it. If it passes the first screening, I'll put it on the Tech Tip index page Monday. John has to "run the credits" yet ... which he may get to today.

Thanks all.

Peg

Tech tip looks good.

OK everyone, I finally got the truck after 7 months of "issues" and got it to the house yesterday!

I have started the process of getting it running. The oil looks good, black, but no contaminates. I pulled the valve cover and the valve train looks fairly clean and not much sludge. The coolant looks nice and green and is not leaking. The throttle linkage was frozen but was easily freed up. Going to check the electrical system next and replace the battery. Going to try to spin the engine over before I apply power to the starter.

I will keep you posted as to the progress. I will probably video the starting when I get a little closer.

Make sure to clean gas tank.

Thanks Don.
I was going to start with a hose from a clean gas tank just to see if it will start and run.

Any other suggestions?

OK, I got the motor to crank over last night. Prior to doing that here is what I did. I pulled the valve cover and inspected the valves and push rods. I lubricated everything under the valve cover. I then pulled the spark plugs and squirted some Marvel Mystery oil in each cylinder. I removed the starter and get it freed up and rotated the flywheel there. A little cumbersome but there is not a bolt on the crank pulley. To my surprise the truck is set up for a hand crank. Which I do not have.

Re-installed the starter and applied battery power. With the spark plugs out I inspected the valves and everything seems to be moving correctly as the starter turned the motor.

Here's the bad news: I did a compression check and two of the cylinders have zero compression. The other 4 have compression ranging from 80 to 105 PSI.

I will inspect to see if perhaps there is some crud that is keeping two of the valves open. I also added some additional Mystery oil to the two cylinders in question hoping that MAYBE there is a stuck ring. Not sure if that is even possible but a friend recommended trying that.

During cranking, the engine sounded normal. Meaning no grinding or clunking or metal on metal sounds like there was a broken piston rod or anything like that, so I am hoping that it is something relatively easy to correct. Like something not moving like it should yet because it has been sitting for so long.

Any other suggestions as to what may be causing this compression issue?

Thanks for the help guys. I will keep you posted as to the progress!

Some heavier oil in the two cylinder's without compression can help determine if the compression is being lost in the top or bottom end.
Add the oil to these two cylinders and recheck the compression. If there is no change it is most likely the top end, if not it may be the bottom.

You may also check to see if the Marvel's you put in the top made it to the oil pan.

OK so I decided to just light it up and see what happens. I replaced the spark plugs, cleaned the points and connected a 5 gallon gas tank.

It took a few minutes to get the fuel system primed but after about 5 attempts to crank it over, she fired right up and ran on all 6 cylinders! Apperently the oil worked and loosened up whatever was stuck open!

I kept her running with my band on the throttle. After about a minute I let go expecting it to die. But she idled just fine. No oil leaks, no coolant leaks and only a small amount of fuel leaking around the carb.

Engine sounds GREAT! No knocking or ticking of any kind. I did shift her into gear and she pulled forward a few inches. Couldn't go far because of the 5 gallon gas tank.

Dump bed went IP and down with no issues.

Added fluid to the breaks and they seemed to be building and holding pressure.

No head lights or running lights. But the wiring looks pretty rough and will need to be redone.

There are a ton of things that I'm going to replace but it was a huge relief to hear her run!

Thanks to everyone here who contributed ideas about getting started.

Congratulations!! It's always a thrill when they fire up for the first time.

Always great to hear that another one has been brought back to life!!!! It's a great day.