1978 Chevrolet C1500 - Page 5 - Answered Questions & Fixed issues

on your harmonic ballancer,sound like your pointer is missing,When you look down at your Harmonic balancer there should be something about it that you see that looks kinda like saw teeth with numbers in the gaps. The zero or line whichever year you have should be on the Harmonic balancer

you can go to libary look up the information in chiltons book just make a copy of that page for vacuum hose diagram

Pretty sure that car had an external regulator. if so, likely it isn't working.

fisrt you need to get a wiring diagram for your car, then you can see where each wire goes.

It is the power for the cross over valve pug it back in to the bullet plug on the switch over valve and that should cure your problem the switching valve changes over the tank sender as well as which tank to pull from. Defauts to driver side if it loses power.

Yes, you would need to inspect for loose wires, etc. Also, consider pulling the alternator and get it bench tested.

Typically what fails are called DIODES. These are one way valves for electricity. They fail, eventually and cause a drain to ground. There are ones dedicated to firing off the regulator. My guess would be this area.

More commonly a problem with the alternator, less with wiring, but anything is possible. Bench test will help you to know...

Doc

more than likely the wire that excites the regulator on top

Pull the driveahaft, pry out yhe old seal wit a flat blade screwdrever, clen up the seal bore of any burs and on the new seal put some #2 permatex on the outer surfave that gores in the seal bore and tap it in evenly, side to side. Try not to **** it or drive it to much at once, The deal goes in with the lip or spring side towards the oil, or sring side in trans. Smooth side out. Good Luck- Ned_

could be a thermostat or a water pump is bad..........replace those 2 things and see what that does for ya

Make sure all your lines and so forth are hooked up. Make sure your reservoir is full then have someone pump the brakes and then hold steady pressure on the brake pedal and you go close to where your brake line connects to the caliper and there should be a small nut looking fitting with a hole in the end. Take a 3/8 wrench or 7/16 which ever and turn that counter clockwise until fluid runs out and the person inside says the pedal is all the way to the floor. Close the fitting with your wrench and have your friend pump the brakes again holding pressure on them then open up the bleed screw again doing the same procedure until you see no air coming out of the fitting. Do this to all of the bleed screws. total of 4. Always make sure you are full of brake fluid before doing the next one.

First, remove the ps belt by loosing the adjustment bolts, then remove the hoses from behind it, then unbolt the bracket from the engine that the pump sits in. I believe that there are three bolts that do this. One off of the exhaust manifold, one on top and one underneath. Once you have gotten pump off of the motor you need to remove the pulley from the pump. KD tools make a great tool for this, part # KD 2897, about 60 bucks at napa. Follow the directions with the tool to remove the pulley and to replace it on the new one. New pumps don't come with the pulley and can be bought with the resevior. The pulley has to come off to get the pump out of the mounting bracket.

This plate is the steering lock plate.It has a lock ring on the shaft but is under very heavy spring pressure which must be compressed in order to remove and re-install. There is a special tool that compresses this spring.It mounts on the steering shaft threads and pushes on the plate.It is quite difficult without but can be done with two persons as one presses and the other removes the lock ring...good luck

look in a junk yard and find one like your and look at how its wired or go to a alt shop and ask them for a diagram.

try running the vehicle without the feul cap and see if it quites or keeps running.

Then you either got the wrong bolt, or the knob part is still in the hole. Take a close look at the bolt you took out, and see if something may have broken off it. If it did, you might be able to get the rest out with a magnet. There is a threadless part on the end of the bolt that's about an inch long. It goes down against the tumbler and hold it in there. The newer ones are a torx head, but i can't remember if 78 is or not.

Should the 2 hoses from the radiator. Top hose from radiator to head, 2nd from radiator to block slides onto the thermostat housing. If you have a 2nd fan that could also have 2 hoses to cool the automatic system. When filling up the radiator - it goes through that into the bottom pipe - into the thermostat housing - around the engine block - into the heater - back through the engine block & out the top hose back to the same cycle. DON'T forget that when you have lost water as you have keep the radiator cap off & let the radiator burp until all the bubbles come out. Sometime you may need to help it by squeezing the hoses, being careful when the engine gets hotter. Good luck

The factory wire to the factory gauge is a solid green wire. that year truck the sending unit usually mounted in the drivers side cylinder head but i have seen some in the passanger side if they have cut the wire and you can goto the main harness connector under the brake master cylinder and booster and find the only solid dark green wire and follow it forward to see how far it back they cut then just splice and run it to your new sending unit . If you want to check to make sure the gauge works after you find the solid green wire put it to a ground and the gauge should go to hot if it does not you have a bad gauge or a cluster wireing in side the truck and that is why they put the aftermarket gauge in .

Put a 4 barrel intake manifold on it.

make sure vacuum modulator on side of trans is not sucking atf through vac. line

Try manually compressing the rod on the vacuum diaphram as if it were working and see if it will release the linkage when the choke is fully open. If that works its probably just a bad choke pull off. Diaphram could be bad in it.