1969 gmc 427 6500

[Adoboloco]

Back at it, recently picked this beauty up. Starting to work on it. Runs good but needs some TLC. First thing will be the master cylinder and then upgrade to a dual circuit master cylinder for extra safety.

I have a feeling finding parts for this will be difficult. Anyone know of any sources?

Progress pics will be updated here @69GMC6500

[jocko]

Nice looking truck! So it has a single res master on it now? Duals were standard on light duty in 67, was there a different rule for the big 'uns?

What are your long term plans?

[Adoboloco]

Thanks... Yes single cylinder with air assist. It’s quite different. I rebuilt a 72 a few years back and it’s completely different.

This is also 5 speed with a split shift.

Long term goal is to rebuild and use for hauling. I’ve already hauled a few pallets... Worked well, but I need to replace the wood deck.

[1972RedNeck]

Originally Posted by Adoboloco

Back at it, recently picked this beauty up. Starting to work on it. Runs good but needs some TLC. First thing will be the master cylinder and then upgrade to a dual circuit master cylinder for extra safety.

I have a feeling finding parts for this will be difficult. Anyone know of any sources?

How will you use a dual reservoir master with the air booster? The master on the firewall basically just supplies a "sense" signal to the air booster that in turn builds the pressure and does all the work.

As for parts, find a heavy truck parts supplier for any drive train parts - I bet they will be readily available.

[68Gold/white]

That's a TRUCK, not a pickup!!!

Some parts stores may be able to help you. Not the kind that has nerds manning the computers that were making slurpies at a convenience store last week though...

You may need casting numbers off of some parts like master cyl, wheel cyl's and such.

We have a local owned independent NAPA where I live, they sometimes can perform great feats!!!

[54blackhornet]

Welcome from Eastern Oregon ! Nice GMC ! If you google your will find a forum devoted to just Big Trucks, one ton and above, great resource...good luck

[Adoboloco]

If the single fails, you lose all breaking ability, air assist won't help at that point. Just want to got that route for modernization and safety, especially when hauling a load.

Thanks for the tip on heavy truck part suppliers.

[Adoboloco]

Originally Posted by 54blackhornet

Welcome from Eastern Oregon ! Nice GMC ! If you google your will find a forum devoted to just Big Trucks, one ton and above, great resource...good luck

Thank you... I'll google that for sure.

[Adoboloco]

Originally Posted by 68Gold/white

That's a TRUCK, not a pickup!!!

But I can haul your pickup with it

I found the shop manual and wiring diagram book on Ebay. It's already been a huge help. Thanks for the tips on sourcing parts etc.

[Old Truck Man]

Ive owned lots of those type of trucks over the decades. The problem lies in the fact that they are not driven daily. and the hyd brakes dry out. and they are expensive to work on. The brake booster cost around $400.00. and they are hard to find. The last one I replaced I had to send my old unit off to get it rebuilt. My current C65 has full air brakes. If you got enough air pressure to release the brake chambers you will have brakes no matter how long its been setting. Ive also owned a couple of those air over Hyd rigs and they weren't so great also.