Re: 1968 GMC - Ol' Blue
 

Thanks! I should have some pretty good visual updates after this weekend. I'm planning to install the column, gauges, finish my power steering plumbing, and tie up some engine bay wiring.

Re: 1968 GMC - Ol' Blue
 

We are getting dangerously close to being able to see if this thing will run. This weekend we got the coolant overflow tank mounted, trans cooler mounted, the intake is mostly done, and the steering column is in. I got a nice rebuilt conversion van tilt column from 70shortfleet. We mocked it up and decided it was too long so we shortened the intermediate shaft. I had no idea that these indents in the shaft were filled with plastic - we heated it up and melted it out so that we could pull it apart, shorten it, drill holes, and bolt it back together. We took 1.5" out of it and didn't have to move the safety switch and it was perfect.

To end the day, we made up the battery cables, put in a few fuses, turned the key and I was happy to see that everything I put in a fuse for, worked. The gauges light up, the check engine light works, high beam indicator works, dome lights work, courtesy lights work, the PCM has power, cigarette lighter works, and the wipers work.

With the long weekend coming up we might just be able to finish up a fairly long list of tasks in order to fire it up. I get so excited and want to make the most of the day so I forget to stop and take pictures. But I'll have the trans cooler, overflow, and intake finished next weekend for good pictures.

Attachment 1961265

Attachment 1961266

Attachment 1961267

Attachment 1961268

Re: 1968 GMC - Ol' Blue
 

Looking great man! Your making good progress! I'm glad your ahead of me, I can take notes ;) Do you think the 10 inch plug wires from Speed Engineering would have been long enough? I need to order some.

Had family in this weekend so I am falling farther behind. But plan to really get a lot done this weekend. What are you doing for power steering lines and will you be using an adapter on the pump?

.

Re: 1968 GMC - Ol' Blue
 

Also, the power steering/hydroboost plumbing odyssey has come to an end. I will put a lot of detail into this post for others to reference.

The hydroboost is off a 95 Astro. I took it apart to put in a new o-ring where the two cases come together since it is a common leak. The master cylinder and prop valve are off the Astro as well. The brake warning switch wire runs to a relay. My understanding is that this is a brake pressure differential switch. So if a leak occurs at the front or rear brakes, the cylinder inside the prop valve moves and the pin on the switch drops and grounds out. This ground is what triggers the relay and turns on the warning light on the dash. From looking at the Astro donor, the rear line goes to the front brakes and front line goes to the rear brakes. The brake line that runs from the master cylinder threaded right in, but I had to get a reducer bushing for the brake front lines. I threw out the old backing plate and made a new one and drilled holes to match up with the brake pedal bracket. In one of my previous posts I show how I matched up the push rods inside the cab.

The pressure lines is where I had the most trouble. I looked at 4 different hydroboost posts from different members and decided I didn't want to spend the money on custom braided lines so I went with mostly OEM lines. One post I had looked at showed pressure lines from a 2004 1500HD worked, but that post didn't include the inner fender which is the cause of most of the struggle as well as the fact that the high pressure and low pressure fittings are not the same size. The fact is, there is very little clearance between the top of the steering gearbox and the inner fender. So through several renditions of this setup, here is what I ended up with:

Hydroboost/master cylinder/prop valve: 95 Astro (rear drums, front disc)

Pressure line from pump to hydro: Sunsong 3401292. I had to make a minor bend to keep the line from touching the pump.

Pressure line from hydro to steering gear: Fitting/end out of hydro is Sunsong 3401299, fitting/end out of gear is Edelmann 71065. There is a guy at one of my local NAPA's that makes custom brake lines and hydraulic hoses. He took the ends I gave him (hard lines) and brazed fittings on them so he could crimp a piece of flexible hose to put the whole thing together. He gave me the hose with the ends attached (uncrimped) so I could mock it up to get the clocking right, then I took it back to him to crimp.

Low pressure return from gear: also custom from NAPA. I ordered a return line end fitting from Rock Auto, but the bend was not tight enough to work. So I had my guy make up a new one and I actually had to bend it a little tighter to fit.

Low pressure return from hydro: 3/8" trans oil line (3/8" barb on hydro and pump)

Pump: 2004 Escalade EXT 6.0 (with hydroboost, so came with 2 return barbs)

I probably have close to $100 into this hodge podge hose now. So if anyone wants to go this route, here is my info. Feel free to ask questions.

Attachment 1961281

Attachment 1961282

Attachment 1961283

Attachment 1961287

Re: 1968 GMC - Ol' Blue
 

Yes, the 10 inch wires would have been long enough. It looks a little silly, but not worth it to me to buy another set.

Funny you mention that, I was typing up my novel on that subject before I saw your post.

Re: 1968 GMC - Ol' Blue
 

Post a pic of the engine bay where I can see the power steering hoses and how the lay in the engine bay. Very good write up. I spent big dollars on the braided lines and I am not sure I like them. It would be hard to swap them out now since I spent the money. I'm afraid they are going to be in the way of my shift linkage. Thanks,

Re: 1968 GMC - Ol' Blue
 

yes please post pics. I was able to make stock PS lines from a 2005, 2500HD truck work with my hydroboost setup but i havent put my inner fender liners or steering column in yet. Thinking at this point it would be easier to modify the inner fender.

Re: 1968 GMC - Ol' Blue
 

I will take some pictures tomorrow or Friday for sure. Cutting the inner fender would have saved me a lot of time and money, but I couldn't bring myself to do it.

Re: 1968 GMC - Ol' Blue
 

Hope everyone had a great Thanksgiving weekend. We got quite a bit done, not as much as I wanted but still a good amount.

The steering wheel is on and actually went about 10X faster and easier than I expected. On my dad's, used a Grant wheel and install kit and ended up having to use a horn contact ring and the cheesy foil stickers and it was just a really lame installation and it took a few tries to get it right. But mine was so much easier. Forever Sharp steering wheel and horn button with a Grant install kit. I literally used maybe 25% of the parts that came with the column, wheel, horn button, and install kit. I didn't know that the horn button was a switch itself which is nice because I only had to take one wire to ground out the button and hook up the other wire coming out of the column.

Also got my DBW pedal done. I had cut off the adjustable pedal assembly because there was no way it would work. There was already an almost 3/8" hole in the arm of the pedal itself so I bent up a piece of 3/8" rod and welded it to the pedal. I had a pedal pad, spring, and pin for the later style pedal that I made work and it came out pretty clean.

Re: 1968 GMC - Ol' Blue
 

Also got my fans and fuel pump wired up and running. I used the GM 3-relay setup for the fans so they both run half speed when the PCM calls for low-speed and they both run full speed when the PCM calls for high-speed. This is a fuse block/relay setup I got from Amazon for $30. I looked at the Bussmann setup and it's nice because it has internal bussing to make wiring a little easier, but I would have spent over $100 because there is a minimum quantity of seals and terminals so I would have ended up with hundreds of them that you don't use. This block worked pretty well - I soldered the 10 ga wires to the terminals since they weren't big enough to crimp. Other than that, the seals fit tight and I'm pretty happy with it. Don't mind the labeling on the wires, we just used leftover wiring from my AAW harness to match the colors used in the GM diagram.

And the intake is done. I used the Spectre 9900B (B for blue filter) kit along with a straight piece of 4" tubing and another coupler to get the clearance from the alternator coming out of the throttle body. I cut off the long mounting arm from the long section of tubing and fabbed up a custom aluminum bracket to firm up the tube to the alternator bracket. Just a heads up for anyone using this kit, it utilizes a clamp from the stock 99-06 intake. It could be done without it, but fortunately we had the part we needed from my dad's 06 leftover as he has a K&N system on it.

I went to prime the fuel system and I've got a couple leaks that I need to figure out. One is the single outlet from the fuel filter/regulator and the other is somewhere at the pump. So here I am regretting the Tanks Inc setup again.

Attachment 1962897

Attachment 1962898

Attachment 1962899

Attachment 1962900

Attachment 1962901

Re: 1968 GMC - Ol' Blue
 

Here are some more pictures of the power steering lines.

Attachment 1962902

Attachment 1962903

Attachment 1962904

Re: 1968 GMC - Ol' Blue
 

Dude. :metal:

Re: 1968 GMC - Ol' Blue
 

Thanks for the pics. That helps a lot. I need to get back to working on mine.

Re: 1968 GMC - Ol' Blue
 

Man, your really pounding out some good work here :chop:

I really like your steering wheel. I've done a grant or two in my day and while they aren't bad, having a quality wheel, column, and internals really makes a big difference. I think grant has low budget, and high budget stuff ;)

Fuse block setup looks nice, I'm thinking of that same 3 relay fan setup as well. Hopefully I pinned the PCM correctly and won't have to go back and redo the engine harness again...

So what exactly is leaking on your fuel setup? I'm using the tanks Inc PA-4 series and didn't have any problems at all back when I pressurized the system and fired up my motor. I'm using A/N to braided line looks like it's the only difference. Curious to see how this one turns out.

Looking good man, keep it up!

.

Re: 1968 GMC - Ol' Blue
 

Thanks guys.

TA - We tested the fan wiring by grounding out the wires we identified as the ground trigger wires to be connected back to the PCM and confirmed that they work as they should. Only time will tell as to whether the wires I have coming from the PCM will send the ground triggers when they're supposed to! I had a mail order tune put on my PCM so that's another variable. Per the GM diagram, once the coolant temp reaches its higher limit, both wires should be grounded. If only the high temp wire is grounded, only one fan will run full speed. But with both wires grounded, both wires run full speed. With only the low temp wire grounded, both fans run half speed.

The first leak is the single supply fitting coming out of the regulator - the one that has all the play in it. I should have lubed up that fitting before pressing it in, I may have messed up the o-ring. I might end up ruining the regulator in pulling that fitting out because of the teeth. Or it may already be ruined if I messed up the o-ring.

The second leak is somewhere at the top of the pump assembly. I tightened up the supply and return fittings and I think they quit leaking but it almost looks like fuel is seeping out where the pickup and returns penetrate the mounting plate. I used Permatex aviation sealant on both sides of the cork gasket and the threads of the screws, but maybe I overtightened the screws. I used anti-seize on the supply and return fittings so I want to take those back out and put Permatex on them and make sure they aren't leaking. I'm also wondering if maybe the fittings are putting some side load on the pickup and return tubes and causing a leak. So lots of variables to explore.

Re: 1968 GMC - Ol' Blue
 

Ok homie.... How did you wire your 3 relay fans with A/C? Are you using a trinary switch? I went through all the old threads and I don't see where anyone really answered this question with certainty when it pertained the following details:

LS Swap - ECM controlling fans
Vintage Air A/C
3 relay setup

LS1Nova71 was the closest I found to explaining this setup but looked like it was never verified....?? http://67-72chevytrucks.com/vboard/s...d.php?t=781007

Thanks man.

Re: 1968 GMC - Ol' Blue
 

Call VA. They told me that I needed the trinary switch.

Re: 1968 GMC - Ol' Blue
 

So for now, I am wired without any A/C considerations because it's going to be awhile before I have my Vintage Air system.

Here's a link to a thread where I found all the info for both scenarios: https://www.67-72chevytrucks.com/vbo...d.php?t=617142

Post #9 (also by ls1nova71) shows the GM schematic for the 3-relay/2 fan setup without A/C. Further into the thread, post #49 from dayj1 has a bunch of schematics on how to keep the PCM and Vintage Air happy. It looks like the links to the pictures are broken, but one of the last 2 diagrams on that post are what I plan on using. I'll reach out to dayj1 about the broken links.

Re: 1968 GMC - Ol' Blue
 

You guys....it runs! I mean, it really RUNS. Saturday we got a lot done:
-Sealed up fuel pump leak (thank you Rectorseal 5)
-Finished the trans fluid lines
-Finished the coolant lines
-Bled the brakes
-Installed shift linkage
-Filled all fluids

We had it running just before lunch - I couldn't believe that it fired right up. We finished up a few items after lunch and by 4:30, it was ready for its maiden voyage. So we threw the seats in it and put about a mile on it. It was starting to get dark, it was a little chilly, I don't have any glass in it and we had to hold the doors closed, but it was awesome. This thing flat out RUNS. I was so glad to hear it start up and that most everything works. No check engine light, no leaks, fans function just as they should, and it's got a nice chop at idle. The steering is easy and the brakes are strong. We were doing about 25 and I gave it about half throttle and the tires broke loose since there's hardly any weight on the back.

Attachment 1964650

Attachment 1964651

Attachment 1964652

Re: 1968 GMC - Ol' Blue
 

Oh man! That is awesome to hear. Very excited for you. You did a good job to get that far and not have any bells, whistles, or leaks.

Re: 1968 GMC - Ol' Blue
 

SWEET!! :truck::burnout::burnout:

That's gotta feel good man. Congrats. I wanna see two black strips on pavement real soon!

Re: 1968 GMC - Ol' Blue
 

Way to go man! Congratulations! :metal:

Re: 1968 GMC - Ol' Blue
 

Thanks guys. It was a huge accomplishment and I'll be starting it just to hear it run every chance I get now. But I have to wait until I have the bed on to take it on a real drive.

Re: 1968 GMC - Ol' Blue
 

I cleaned up/rebuilt the marker lights. New lenses, gaskets, and lamps. I'm developing an appreciation for OEM parts. For instance, these buckets are quality pieces and no repro part could ever match it. All I did was clean it up a little bit and it looks as degraded after 51 years as a modern piece would look after 10 years.

I didn't use the rivets that came with the lenses because I hate them, so I used aluminum rivets we had on hand. Then I found out that I need to relocate my trans cooler lines because I can't get this assembly in on the passenger side!

Attachment 1965347

Attachment 1965348

Re: 1968 GMC - Ol' Blue
 

Looking good. I'm glad you posted this. Im planning to recess my parking lights so you can't see them and I need to mock this up now before I install my trans cooler lines in radiator...

Your not going with LED? What's your reason on this man....? ;)

.