Re: THANK YOU... And Need help identifying this truck
 

I can tell you what I had to do on my truck, and it only had 8,021 miles on it in 2012 when I got it, I had to rebuild the entire Brake & Clutch Hydraulic system including the Hydra-Boost, I had all but one wheel cylinder leaking, and the master cylinder was full of dirt, and this truck spent most of its live inside, from 1965 to 2004 when it was taken out of service.

I covered most of this in my Builds & Journals theard, 1965 GMC 3500 Rescue Squad, starting on page 4.

Hope this helps you out some, keep in mind my truck is a tad smaller, its a 3500.

Re: THANK YOU... And Need help identifying this truck
 

By the way, your truck once had the "GMC 4000" Emblem at the top of the fender near the door, but I can see that someone did a sheetmetal repair there and looks like they discarded it.

Re: THANK YOU... And Need help identifying this truck
 

If you have uncovered the engine ID yet, looking at the pics of the engine it appears your truck has the optional 305C V6 rather than the standard 305E. The distinguishing characteristic is like all 305C engines is it has the higher mounted water pump & housing rather than the lower mounted style of the 305E. What that also means in 4 rings per piston rather than 3 & valve rotators.:thumbsup:

Re: THANK YOU... And Need help identifying this truck
 

All,
I want to thank everyone here for helping me get this far along. Some updates:
1) I put brake fluid in the master cylinder, and pumped it full for about 15 minutes. Fluid turned rusty, then brakes started to get a better feel. And as mentioned, the clutch worked as well. I took a picture of the master cylinder, the line on the left goes to the clutch. Never heard that one before. So, there must be a leak somewhere, will have to trace that one down.

2) Scraped the motor block as suggested, found the stamp. 305E. Was hoping fora bigger motor for a 4000 series, but I guess you get what you get when you inherit :) .

3) Moved the truck a bit, reverse still sounds TERRIBLE when shifting, may need some work on that.

4) The high/low on the transmission shifter is in a picture as well.

5) The oil hasn't been changed in probably a decade, according to my uncle. The truck was only used for a couple weeks a year, to pull the crop out of the field, and taken to the elevator. Only thing Uncle did was put brake fluid in it... Can't wait to change that oil.

6) I have gas leaking from the carb after a couple of minutes of running. from the point in the picture.

7) Not sure what the other brake line is for, I will have to trace that down as well.

No lift that I can see on the truck.
The VIN # is
V4008 P G8023E

Thank you again everyone for the help. If anyone has any ideas on how the clutch works with the brake master cylinder, or any information on what I have provided, that would be great. You all have been very generous in your information.

Re: THANK YOU... And Need help identifying this truck
 

The 305 was the only V6 in the 4000 series in 63 but what is odd yours is a 305E with the water pump housing that comes with the 305C, could the engine have been replaced at some point?

Re: THANK YOU... And Need help identifying this truck
 

My '63 4000 had the shift integrated with the shifter knob. That looks like the standard "afterthought" type. Since yours isn't a "Heavy Duty" I wonder if the two-speed rear was added (dealer order?)

V = Vacuum Hydraulic Brakes
40 = 4000 series (typical 23,000 GVW class)
08 = 175" Wheelbase

P = (build plant?)

G = 1963
8023 = 7023rd truck built
E = 16,001 - 19,500 GVW Rating

----------------------------------------
For comparison:
----------------------------------------
*My* 1963 4000 series
VH4016 G1750F
V = Vacuum Hydraulic Brakes
H = Heavy Duty
40 = 4000 Series (23,000 GVW class)
16 = 223" wheelbase

G = 1963
1750 = 750th truck built
F = 19,501 - 26,000 GVW
Mine is actually rated at 24,000

On Driver's Kickpanel:

Re: THANK YOU... And Need help identifying this truck
 

Actually a 351 was available as an option for 1963. Or so states the plate in my '63 4000 series.

Re: THANK YOU... And Need help identifying this truck
 

Hello all,
A quick update on the 4000 series. First, thanks again everyone, I appreciate even more information.

Got the truck started again, and reverse didn't grind, and first worked great. Then my luck ran out, and must have lost pressure in the brakes and clutch. Put the big ol boy right through my metal barn wall. Just didn't want to stop, and the brakes didnt stop it, and the clutch wouldn't let it go into neutral. No stopping that big boy, and I didn't pull the ignition key fast enough. Wife not happy.

So I will be tracing down the leak, it must be somewhere. Oddly enough, after I pumped the brakes and the clutch a couple of times, I was able to start in neutral and back out just a bit (so I could fix the barn).

I want to change the oil, but I am getting two different types of oil filters. One looks huge, and the other is a standard mobile 1 filter. The filter looks giant on the motor, but I am not sure it is in some housing or not.
Has anyone ran the SeaFoam through one of these engines prior to changing the oil? Knowing the oil hasn't been changed in at least 10 years, I am a bit concerned about damage from the SeaFoam.

And how does the clutch share the master cylinder with the brakes?

Thanks again everyone, I really appreciate all the help.

Re: THANK YOU... And Need help identifying this truck
 

Your master cylinder has 2 chambers, one for the brake and the other for the clutch. Each with it's own fluid reservoir, they are just under one cap. Each has their own piston actuated by their respective pedal. If it pumped up and then lost pressure on the clutch or bake, then I would suspect a leaking wheel cylinder and clutch slave. NAPA has new ones at very reasonable prices, almost too good so rebuilding is in question. Like I mentioned, figure on rebuilding the entire system, it will save the other walls of the barn.;)

Re: THANK YOU... And Need help identifying this truck
 

They had two different styles of 2 speeds One was electric and that one is actuated by vacuum