Charlotte - A Stock 1970 K10 Build

[Love 70 Chevys]

Hey Shinysideup thanks for the compliment! I am often very near you. My daughter lives in Clermont and we visit her 3x a year. Am always scouring the Orlando Craigslist looking for 67-72 parts. Just missed out on a beautiful rust free rear step bumper there that I need by a day! Oh well, should not have procrastinated. Just wasn't sure how I would get the 200lb beast on the plane! Would love to see your truck sometime.

[Love 70 Chevys]

Am now in the process of rebuilding the carb. Another great history project for me!! It is a Rochester Monojet. Now everyone has heard of the Rochester Quadrajet, but they made a lot of money on Monojets! Literally made in my back yard. One of my club members worked in the plant there for years making these things. The plant still exists, but now makes fuel injectors and fuel pumps for GM. (Not still owned by GM, but a supplier to them and others.)
Mine has a date code, is original to the truck, and it is a 1970. The other interesting thing is that even though it is the Rochester Monojet design, in years when the Rochester plant (which I work within five miles of) could not keep up with orders, GM also built the Monojet at the Bay City plant just north of Detroit. Mine was made in the Bay City plant. I researched it, and that plant still exists. They still supply castings for GM. I bought a rebuild kit that contains gaskets, seals and a float that are ethanol resistant. I have taken it apart, and even though the gaskets were dry and mealy, there really was not much carbon build-up or gunk it it and everything moved freely. This process has just begun, and I am going to keep my promise and do a better job of documenting this so someone else can follow right along later should they need to do so. Just a few preliminary pics so far. Explanations to follow as I get deeper into it!

[2014sierraAT]

Awesome truck, what a find!

[Greg58]

The grill turned out great, keep the progress going.

[70LonghornCST]

Welcome to the board! Very nice looking truck. I'm excited to see this as you complete your build. Have fun with it!

[renegade6]

Great build. Love all of the details you are putting in it.

[Andyking1203]

Great looking truck... and your doing great at bring back the good of the old!!!

[Love 70 Chevys]

So here goes...taking the carb apart. I will be rebuilding it using a kit from Mike's Carburetor Parts in Chehalis, WA. It is kit K4007 with the PK106 upgrade. (Adds a new float.) He also has some really good videos on YouTube. First step is to remove two screws and the air cleaner bracket. Screws came out very easy.

[Love 70 Chevys]

Next step is to take out six bowl cover screws. They are different lengths, so I bagged, tagged and made a diagram of what went where. They also came out very easy. Got out lots of little bins and old pill bottles to hold all the small parts so things will stay organized.

[Love 70 Chevys]

A couple of love taps with a rubber mallet, and the bowl cover separated from the float bowl assembly. Upper picture is the underside of the bowl cover and the lower is the float bowl assembly. You can start to see all the cool stuff that makes a carb work. The gasket was dry and crumbly, I scraped it off with a razor blade. The kit contains all new gaskets.

[Love 70 Chevys]

Next was removal of the vacuum brake diaphragm. It is located in the bowl cover. The bowl cover contains the choke plate. The cover has two screws. Again, no struggles. The kit contains a new diaphragm. (The old one looked fine, but I will replace anyway.) The link assembly was also removed for cleaning.

[Love 70 Chevys]

Removal of the old float came next. There was quite a bit of crud down in the bottom of the bowl from the decaying gasket. It didn't seem to be in the area of the needle valve, so it probably wasn't causing too much of a problem. One slide clip that can be pulled with finger tips and the float comes right out. The kit has a new metal one, supposedly the original ones are made of a material that tends to absorb gas over time. It's good to get the needle bagged up now before it gets lost. (The kit comes with a new needle, but I like to keep all the old parts as sometimes new parts are not always what I hoped for!)

[Love 70 Chevys]

It was all going much too smoothly at this point, so the law of averages said something had to become a struggle! The next step is to remove the pump and power link lever by removing the screw with the blue arrow. Unfortunately, it is a slotted head screw and fairly soft. Even with hours of PB blaster soaking, taps with a hammer and time in a vise, it would not budge. I went to plan B which seemed to work fine. I just left it be and pried out the link to the pump at the lower right red arrow and the link to the power piston rod at the upper left red arrow. Now the pump and piston rod are free and can be removed from the float bowel assembly.

[Love 70 Chevys]

Now that the links were disconnected, the pump (red arrow) and the power piston assembly (blue arrow) could be removed. The kit comes with replacement springs and a new seal for the pump.

[Love 70 Chevys]

And now I am out of time for tonight! Will post more pictures tomorrow. Disassembly is complete. The parts have been soaked in carb cleaner and cleaned with some old tooth and artist brushes. They look much better squeaky clean. Will post pictures up to that point, and then take more as I put it back together.

[Love 70 Chevys]

Next was to separate the throttle body assembly from the float bowl assembly. I forgot to take a picture, but have included a portion of the diagram. To remove the throttle body, all that is required is to remove two screws. (Labeled 45). They are large and obvious.

[Love 70 Chevys]

In fact, while I am at it, I should include the whole exploded view of this era Rochester Monojet. Hopefully others will find this to be as useful as I did!

[Love 70 Chevys]

Next step was to remove the pump check ball spring guide so the spring and ball could be removed. This is all held in by a "T-shaped" sheet metal part that is pressed into a groove. It can be pulled out by needle nose pliers. The red arrow points to the pliers as my crummy looking pliers blend right into my crummy looking (at this point) carb! The blue arrow points to the guide that can be plucked out. The lower picture show the three very small parts after removal. (Good to have those old prescription pill bottles to put stuff like this in.)

[Love 70 Chevys]

Next was removal of the fuel filter nut. The gasket was there, but there was no filter, or the spring that is supposed to be behind it. The truck currently has an aftermarket filter in the fuel line going to the carb, but I am going to see if I can scare up an original if possible. Don't know about the spring, that might be a bit trickier. Will have to research a bit!

[Love 70 Chevys]

Last step in the tear down process was to remove the bracket that the throttle linkage spring secures to. I did not include pictures of disassembly of the throttle linkage done on the bench. I do have pictures (and videos to show movement) of the linkage when it was in the truck. I am going to do corrosion control and painting of those parts also. I'll include pictures of them in the reassembly portion of this post when I do it. I have seen other threads where many people have inherited years old jury rigged set-ups and wonder how they came from the factory. I don't think mine has ever been messed with, so hopefully some good pictures of the configuration can help someone.

[Love 70 Chevys]

The only parts I seem to be missing are the fast idle cam and the choke rod and shoulder screw that go along with it. I was very fortunate to find out they are still available and I will order those parts. My truck has the "coiled thermostat" type of automatic choke and that was still present on the motor along with the rod. The vacuum line that goes to the advance on the distributor (partially solid tubing, partially rubber hose) is still there. Clips for this are also still in place on the valve cover. I am very lucky in this area to have most everything factory-like and in place. Last step was to get the now stripped castings clean. I scraped off all the over spray and heavy duty grunge and soaked them in Gunk carb cleaner. Gunk makes a perfect sized can for carb parts that includes a nice soaking basket to make fishing the parts in and out easier. ($21 at Advance Auto if you use the 20% order on line, but pick up in store coupon.) Bottom picture is the nicey nice castings all ready to be put back into a hopefully "like new" carburetor! I have not started this work yet, but when I am done, I will post the pictures.

[Love 70 Chevys]

It has been a few weeks since I last posted, but I have finished the carb, so I will share the reassembly steps. After all the parts were degreased and washed, I used some dentist type picks to get into all of the nooks and crannies on the outside of the castings to get rid of any stubborn deposits. Then I cleaned everything with acetone, roughed everything up with a scotchbrite pad and then cleaned with acetone again. Hung all the parts with wire and went to a friends house who was kind enough to let me use his nice big heated garage and put three coats of high temp engine enamel on. My new paint stand is the base to the cymbal portion of an old drum set I found dumpster diving.

[Love 70 Chevys]

Put a fresh new gasket on the throttle body assembly.

[Love 70 Chevys]

Used Loctite 242 on all screws (removable) and put the two screws back in to secure it the float bowl assembly.

[Love 70 Chevys]

Put the power piston back into the float bowl casting. The rebuild kit came with a new replacement spring.