1967 C-50 Dump truck Project

[71'tahoe]

I picked up a couple clutch/brake pedal assemblies from Todd Rusk at the Freeman's swap meet in Indy this past weekend. This photo is the C/10/20/30 assembly right before I took it all apart.

[71'tahoe]

Here are a couple photos of the stock C/70 pedals and the C/10 pedals swapped onto the C/70 bracket. I need to look for the pivot shaft bushings as mine are about wore out.

[71'tahoe]

I didn't get many in progress photos of the pedal swap due to being caught up in forward progress. Here are some photos of the hydro boost being mocked up and you can see where I had to drill some extra holes.

[CarolinaHD]

I bought a used one that had the master cylinder bore rusted so I ended up getting a new unit on ebay. Paid $150 for the used one and $400 for the new one. He was asking $800 and he accepted my first offer of $400. He has a few more for sale on there or you can check car-part.com for used units. I'll grab some more pictures tomorrow for everyone.

[71'tahoe]

Thanks Alex. I'll look into it. Yeah any extra photos you have would be great! Do you have a build thread for your truck?

[Campbel45]

FYI, the hydromax can be found in number of medium duty trucks. I've seen them in the chevy/gmc c4500-6500, Ford F550-800, and international 4700. I'm not sure if there is a difference between brands. You may check craigslist or marketplace for someone parting out a truck.

Another thing I'm not sure about is the required power steering flow/pressure for hydromax. I assume it requires more than hydroboost?? You might want to look into what your pump is rated for and whats needed for hydromax. Perhaps CarolineHD has some info?

[CarolinaHD]

Originally Posted by Campbel45

FYI, the hydromax can be found in number of medium duty trucks. I've seen them in the chevy/gmc c4500-6500, Ford F550-800, and international 4700. I'm not sure if there is a difference between brands. You may check craigslist or marketplace for someone parting out a truck.

Another thing I'm not sure about is the required power steering flow/pressure for hydromax. I assume it requires more than hydroboost?? You might want to look into what your pump is rated for and whats needed for hydromax. Perhaps CarolineHD has some info?

That's correct, I've seen the same casting numbers for the hydrobooster in all those that you mentioned,#2772114. Theres about 5 different casting numbers that I've found. The differences seem to be with the master cylinder and backup pump. I'll get my wife's laptop and get all this info in one thread but here is an excerpt about flow rate from the Bosch manual:


"The booster is designed to perform in a flow range of 3.2 to 5.0 gpm. Flow rate through the
booster can impact vehicle stopping distance; therefore, the vehicle manufacturer must determine
the required minimum flow rate. Flow rates below 3.2 gpm can cause slower response times when
the booster is applied. Flow rates higher than 5.0 gpm may contribute to the booster self-applying,
which will cause brake drag or fluid overheating.
The fluid power source must be capable of supplying 1,000 psi to the booster plus any additional
pressure required by other devices in the system such as a power steering gear.
If a power steering gear is used, the steering gear must be "balanced" so that it can handle the
pressures generated in the steering gear return line. It must also have an internal relief valve
setting lower than the pump relief to allow the steering gear to relieve before the hydraulic pump
does. It must also have an internal by-pass to allow manual steering during booster backup system
operation. The manufacturer must adhere to the flow path illustrated in Figure 2.

[Campbel45]

Thanks CarolinaHD! Awesome info

[71'tahoe]

Originally Posted by CarolinaHD

That's correct, I've seen the same casting numbers for the hydrobooster in all those that you mentioned,#2772114. Theres about 5 different casting numbers that I've found. The differences seem to be with the master cylinder and backup pump. I'll get my wife's laptop and get all this info in one thread but here is an excerpt about flow rate from the Bosch manual:


"The booster is designed to perform in a flow range of 3.2 to 5.0 gpm. Flow rate through the
booster can impact vehicle stopping distance; therefore, the vehicle manufacturer must determine
the required minimum flow rate. Flow rates below 3.2 gpm can cause slower response times when
the booster is applied. Flow rates higher than 5.0 gpm may contribute to the booster self-applying,
which will cause brake drag or fluid overheating.
The fluid power source must be capable of supplying 1,000 psi to the booster plus any additional
pressure required by other devices in the system such as a power steering gear.
If a power steering gear is used, the steering gear must be "balanced" so that it can handle the
pressures generated in the steering gear return line. It must also have an internal relief valve
setting lower than the pump relief to allow the steering gear to relieve before the hydraulic pump
does. It must also have an internal by-pass to allow manual steering during booster backup system
operation. The manufacturer must adhere to the flow path illustrated in Figure 2.

Alex,
Again thanks for being a big contributor to this build! I'm gleaning as much information as I can from your knowledge!

[CarolinaHD]

http://67-72chevytrucks.com/vboard/s...59#post8680859

Did the best I could on my phone, my pics are always sideways. I'll make a build thread at some point..

[71'tahoe]

Originally Posted by CarolinaHD

http://67-72chevytrucks.com/vboard/s...59#post8680859

Did the best I could on my phone, my pics are always sideways. I'll make a build thread at some point..

Thanks for the link! I went down to the local medium duty truck I used to work at years ago. I found a few trucks sporting the same system. I'll post photos when I get a chance.

Also Thanks for all the information on the hydro brake setup.

[CarolinaHD]

Going to atlanta and kentucky this week to pick up 2 c50s. Let me know if you need any parts.

[71'tahoe]

Originally Posted by CarolinaHD

Going to atlanta and kentucky this week to pick up 2 c50s. Let me know if you need any parts.

C/50's?
I could use some steps from either a 50 or a 70. I'll have to do an inventory of what other parts I need. I'll try to update the project soon.

[CarolinaHD]

As in mutiple c50, 67 and 69. Sorry bout that

[71'tahoe]

Ok I have an idea in the back of my mind to try and piece together a decent C/50 truck with my left over parts and running gear. I'll probably update this in project with in the hour. I just got home and need to take care of a few things before I get on the computer. I just wanted to respond your reply about parts.

[CarolinaHD]

10 4 I'll let you know when they're in my possession

[71'tahoe]

Originally Posted by CarolinaHD

10 4 I'll let you know when they're in my possession

Did you get your trucks?

[71'tahoe]

So it's been awhile since I last posted an update. Things have been busy with my transportation company and my shop. last summer I bought a piece of land so I could build a bigger shop. So a few weeks ago we broke ground and started laying out the driveway. Man, what a mess. It had never gotten cold enough these last few months for the ground to freeze and we got tired of waiting. So I'll add some photos of that progress. I also used my 1977 GMC 3500 grain truck to haul several loads of rock to help get the driveway started.



I have done a little work on the Kansas cab. I also went to the local medium duty truck shop where I used to work to look for a Top Kick Electric/Hydro Boost. I did find one but haven't went back to grab it yet. I've been going over the body panels and taken a mental note of what needs done.

[71'tahoe]

Here is the photos of the progress on the new property.

[71'tahoe]

I've been kicking it around the idea of doing a 12 valve swap and as mentioned in my first post, I intend to use this truck both for the farm and the local stone quarry. A quick little story that goes along with this next update: I have a friend, who works at our local school as a bus mechanic, ask me if I would be interested in becoming a substitute bus driver in all of my spare time...

I said why not. So I went through the classes and was ready to do all the driving tests, then the pandemic hit. So much for that...

Anyways, during the time of turning in paperwork and in general, just stopping by the bus garage to hang out, I was told about a bus that had a 12 valve cummins with a newer rebuild on the engine. So I asked how much and it was a bid kinda thing. So as of yesterday, I became the owner of my old high school band bus....

I'm not a 100% sure just how the project will go from here on out but I know I will figure out the best route for my needs before too long.

[CarolinaHD]

Awesome looks like you got plenty of work cut out for you! This virus crap shutdown my plans of getting those other 2 trucks but I still plan on getting them this summer.

[71'tahoe]

Originally Posted by CarolinaHD

Awesome looks like you got plenty of work cut out for you! This virus crap shutdown my plans of getting those other 2 trucks but I still plan on getting them this summer.

Yeah I think your right! I do. It'll be fun project.

[CarolinaHD]

Copied this from the other thread.....


The following is for a 1967 c50 with 5000lb front axle, 15,000lb 2 speed vacuum shifted rear axle, and midland vacuum brake booster.

Front 14x2 shoes- Centric 111.02990
Rubber brake hose master cylinder- Dorman h38908
Rubber brake hose front wheels x2- Dorman h36697
Rubber brake hose rear axle- Dorman h71305
Brake master cylinder- Dorman m630823
Front right brake wheel cylinder- Raybestos wc19091
Front left brake wheel cylinder- Raybestos wc19090
Rear brake wheel cylinder x2- Raybestos wc37159
Rear brake wheel cylinder x2- Raybestos wc37160
5000lb front axle kingpin rebuild kit NO REAM- Stemco k51g
Moog plastic bushing kingpin rebuild kit- 8492n
Kingpin thrust bearing- timken t110
Front wheel bearings x2- timken 3578a and 15103s
Front wheel bearing race x2- timken 3525 and 15243
Front wheel seal- timken 8975s
Rear wheel bearings x2- timken 3982 and 33287
Rear wheel bearing race x2- timken 3925 and 33472
Rear axle vacuum shift diaphragm- Bendix 374451

Should be about everything except rear wheel seal, rear shoes, and brake spring kits.

All axle related parts are the same for 1965-1974 4000, 5000, and 7000lb front axles.

[71'tahoe]

Originally Posted by CarolinaHD

Copied this from the other thread.....


The following is for a 1967 c50 with 5000lb front axle, 15,000lb 2 speed vacuum shifted rear axle, and midland vacuum brake booster.

Front 14x2 shoes- Centric 111.02990
Rubber brake hose master cylinder- Dorman h38908
Rubber brake hose front wheels x2- Dorman h36697
Rubber brake hose rear axle- Dorman h71305
Brake master cylinder- Dorman m630823
Front right brake wheel cylinder- Raybestos wc19091
Front left brake wheel cylinder- Raybestos wc19090
Rear brake wheel cylinder x2- Raybestos wc37159
Rear brake wheel cylinder x2- Raybestos wc37160
5000lb front axle kingpin rebuild kit NO REAM- Stemco k51g
Moog plastic bushing kingpin rebuild kit- 8492n
Kingpin thrust bearing- timken t110
Front wheel bearings x2- timken 3578a and 15103s
Front wheel bearing race x2- timken 3525 and 15243
Front wheel seal- timken 8975s
Rear wheel bearings x2- timken 3982 and 33287
Rear wheel bearing race x2- timken 3925 and 33472
Rear axle vacuum shift diaphragm- Bendix 374451

Should be about everything except rear wheel seal, rear shoes, and brake spring kits.

All axle related parts are the same for 1965-1974 4000, 5000, and 7000lb front axles.

Thanks!! I will be searching for the parts tomorrow.