1976 3/4ton 4x4 Shortbed - Page 5 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**l79m20** · 09-21-2014, 10:22 PM

Sooooooo..........last post was about getting the rear cylinders on and having a full pedal. Well thats all true, until you start the truck, and then the pedal is gone, turn truck off, pedal pumps back up and is fine. Thought the booster was bad, so took a known good one off a parts truck and replaced it. Same issue. Did some searching on the net and saw some people saying the proportioning valve had to be adjusted. Turn key on, press in adjuster on the valve and then bleed. Tried that with no significant results. I am hoping someone can shed some light on my issues.

twangismythang · 09-25-2014, 10:10 PM

I'm diggin where your goin with the truck, I will stay tuned.

**l79m20** · 10-05-2014, 10:02 PM

Im dying here guys, cannot get this brake thing figured out. Decided to swap out the master cylinder with a remaned unit since its just $16. Bench bleed, and installed, NO DIFFERENCE. If I block off the vacuum to the booster I can run the truck and get the brakes to grab and stop it with a bit of pumping. That is not possible with the vacuum to the booster connected. I took apart a different booster that I had put on the truck and the diaphragm was in great shape. I dont want to buy a $115 booster and have the same issue. I am just stumped at this point. Any help would be appreciated.

**l79m20** · 09-23-2015, 09:09 PM

A year has gone by and lots of work has come with it. Brake problems are sorted out. Feel like a moron, but it was a simple fix. When I put all the new pieces in the rear I had to move the adjuster all the way in to get the hubs off. Well, I forgot to adjust them back when I replaced everything, soon as I did that, they work no problem. Also had a motor issue. When I first put it back in I filled it with water to save wasting antifreeze if I had a leak anywhere. No leaks. When I put the truck away for winter I drained the radiator and let the motor run to pump any extra water out. As it turns out there was a bit too much water left in and it popped the block right next to a freeze plug.

**l79m20** · 09-23-2015, 09:16 PM

A friend of mine bought a 67 with a 383 in it and didnt want the motor. We tore his truck apart for his build and he was kind enough to let me have the old motor. I took it home, cleaned it up a bit, nothing like the last one, and crammed it home. Got everything hooked back up, plumbed and wired, and she fired right up. I did manage to get the interior cleaned out again and my new rubber floor mat installed. The only problem I am having now is with getting it timed just right. I can jump in it after its set for a week or more and it will start right up once it gets fuel. It will idle beautifully. When I drive it, it will run ok but then acts like its starving itself for fuel and die. Then it wont even begin to start, and will smell like its flooded. If it doesnt die while driving it will diesel hard before it shuts off. It has a manual choke edelbrock on it. I have read that these carbs tend to run rich. But again, I am not sure its even timed correctly. The guy my friend bought the truck from said it was a 383. It does have aftermarket dart heads on it and roller rockers. Its an80-84 4 bolt 350 block. But i dont have any info on the rest. Any tips would be appreciated.

09-21-2014, 10:22 PM	#101
l79m20 Registered User Join Date: May 2005 Location: Reading, Kansas Posts: 628	Re: 1976 3/4ton 4x4 Shortbed Sooooooo..........last post was about getting the rear cylinders on and having a full pedal. Well thats all true, until you start the truck, and then the pedal is gone, turn truck off, pedal pumps back up and is fine. Thought the booster was bad, so took a known good one off a parts truck and replaced it. Same issue. Did some searching on the net and saw some people saying the proportioning valve had to be adjusted. Turn key on, press in adjuster on the valve and then bleed. Tried that with no significant results. I am hoping someone can shed some light on my issues.

09-25-2014, 10:10 PM	#102
twangismythang Registered User Join Date: Oct 2012 Location: Memphis, Tn. Posts: 219	Re: 1976 3/4ton 4x4 Shortbed I'm diggin where your goin with the truck, I will stay tuned. __________________ Victory will only be achieved through superior firepower and trusting in the Lord. SOLD 68 C-10. http://67-72chevytrucks.com/vboard/s...d.php?t=560975 SOLD 2000 Silverado...http://67-72chevytrucks.com/vboard/s...=1#post6492671 87 V-10 4X4 http://67-72chevytrucks.com/vboard/s...d.php?t=643898

10-05-2014, 10:02 PM	#103
l79m20 Registered User Join Date: May 2005 Location: Reading, Kansas Posts: 628	Re: 1976 3/4ton 4x4 Shortbed Im dying here guys, cannot get this brake thing figured out. Decided to swap out the master cylinder with a remaned unit since its just $16. Bench bleed, and installed, NO DIFFERENCE. If I block off the vacuum to the booster I can run the truck and get the brakes to grab and stop it with a bit of pumping. That is not possible with the vacuum to the booster connected. I took apart a different booster that I had put on the truck and the diaphragm was in great shape. I dont want to buy a $115 booster and have the same issue. I am just stumped at this point. Any help would be appreciated.

09-23-2015, 09:09 PM	#104
l79m20 Registered User Join Date: May 2005 Location: Reading, Kansas Posts: 628	Re: 1976 3/4ton 4x4 Shortbed A year has gone by and lots of work has come with it. Brake problems are sorted out. Feel like a moron, but it was a simple fix. When I put all the new pieces in the rear I had to move the adjuster all the way in to get the hubs off. Well, I forgot to adjust them back when I replaced everything, soon as I did that, they work no problem. Also had a motor issue. When I first put it back in I filled it with water to save wasting antifreeze if I had a leak anywhere. No leaks. When I put the truck away for winter I drained the radiator and let the motor run to pump any extra water out. As it turns out there was a bit too much water left in and it popped the block right next to a freeze plug.

09-23-2015, 09:16 PM	#105
l79m20 Registered User Join Date: May 2005 Location: Reading, Kansas Posts: 628	Re: 1976 3/4ton 4x4 Shortbed A friend of mine bought a 67 with a 383 in it and didnt want the motor. We tore his truck apart for his build and he was kind enough to let me have the old motor. I took it home, cleaned it up a bit, nothing like the last one, and crammed it home. Got everything hooked back up, plumbed and wired, and she fired right up. I did manage to get the interior cleaned out again and my new rubber floor mat installed. The only problem I am having now is with getting it timed just right. I can jump in it after its set for a week or more and it will start right up once it gets fuel. It will idle beautifully. When I drive it, it will run ok but then acts like its starving itself for fuel and die. Then it wont even begin to start, and will smell like its flooded. If it doesnt die while driving it will diesel hard before it shuts off. It has a manual choke edelbrock on it. I have read that these carbs tend to run rich. But again, I am not sure its even timed correctly. The guy my friend bought the truck from said it was a 383. It does have aftermarket dart heads on it and roller rockers. Its an80-84 4 bolt 350 block. But i dont have any info on the rest. Any tips would be appreciated.



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