1967 C-50 Dump truck Project

[71'tahoe]

I had some time to look at the hydro boost units tonight. I was a bit off in my list of units. The 95' was supposed to be an 85' so that makes 2 square body inits and an 03'. The 03' has a flat plate with 4 studs. none of which fit any of the existing fire wall holes. The square body unit fits in 2 holes on my 71' C/10 firewall but does not fit on the Kansas cab. I will need to open up the sides of the existing holes the drill a couple more. The actual hydro boost units look similar except the mounting bracket. I like the 4 stud bracket so I'm not sure which I'll go with.

[71'tahoe]

Here is the amount of rust on the driver side rocker. Floor is pitted but very solid. I think I may just cut the top portion of the rocker instead of the whole thing.

[71'tahoe]

Can you replace the rocker with out cutting out the cab corner? The driver side cab corner is solid with zero rust. I'd hate to cut it out.

[71'tahoe]

I also pulled out the Ididit column I have for my 56' chevy truck to see how it would fit. This column is 30" I think a 32'' or a 34'' would fit better. I hope the steering wheel has the same spline count and diameter.

[71'tahoe]

I didn't get much done today. I did elongate the holes in the firewall so I could mock up the square body hydroboost. I will need to find a set of pedals and the dash bracket from a manual truck. The factory C/70 pedal box doesn't have much room for altering the booster holes. So If anyone has a kine on some pedals and the pedal box (pedal mounts/firewall mount) let me know. I'm going to try the Facebook C/10 groups in Ohio,Ky,and Tenn. I'll try to grab some photos tomorrow.

[Pvmt-Pndr]

There's a guy up the road from me. I'm not sure if he ships or not but he only deals with Chevy trucks, you never know what he might have laying around. His name is Howard and he owns Dundee Truck and Trim in Dundee MI. 734-529-5934

[71'tahoe]

Originally Posted by Pvmt-Pndr

There's a guy up the road from me. I'm not sure if he ships or not but he only deals with Chevy trucks, you never know what he might have laying around. His name is Howard and he owns Dundee Truck and Trim in Dundee MI. 734-529-5934

Some how I missed this. I'll look him up. I went out to Indy for a swap meet and got a couple sets of pedals.

[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.

[71'tahoe]

Originally I started to drill the bottom holes in the fire wall where the factory hydroboost holes were but then realized they wouldn't hit the factory C/70 fire wall mount/brace. I'll just weld up the factory H/B holes when I pull everything down for cleaning and paint. I'm also going to make a plate to extend the H/B plate up to the top pedal mount/fire wall brace. That way it'll look more uniform.

[71'tahoe]

Here are few photos of the factory 6 holes for the pedal mounts/fire wall brace. I ended up using all of these and altered the square body H/B mounts. I still need to address the ripped/missing piece with new metal and also need to drill out the spot welds on the C/10 pedal mount and weld it to the C/70 pedal mount.

[71'tahoe]

Here are a few photos of the pedals. I will have to weld on a tab on the brake pedal to make sure the factory H/B are will be able to attach and let my brake pedal line up with the clutch pedal. The last photo is the cross bar that holds the pedal stops/bumpers. I didn't get one on this set of pedals so I either need to locate one or build on. It allows the pedals to come back up to a consistent location when both are at rest.

[71'tahoe]

I also picked up the headlight switch and connector,ignition switch,key, and connector. I'll probably be making my own harness for this truck so I wanted to get a jump on purchasing the dash items.

[71'tahoe]

I cut open the driver side cowl panel today. It's not terrible but it'll be fun making the new patch panels.

[CarolinaHD]

Nice steady progress I like it! Take lots of pictures when you replace the wheel cylinders, that what I have left next on my c50. I just finished up this hydroboost swap in my 67, came out of a 2007 c5500. Bosch hydro-max with a 2" bore master cylinder, just another option for this watching. Bolted right in no modifications except for the pedal push rod was cut down.

[Campbel45]

Hey CarolinaHD, I was thinking of using the same system on my C50. Mind giving more details on how/where you bolted the push rod to the brake pedal? whats your pedal ratio? I've been searching around to make sure my pedal ratio is correct so the brakes dont feel hard/soft.

[Campbel45]

and 71'Tahoe great thread going so far! I've enjoyed the reading and pictures. I too would've moved onto the Kansas cab. We may see each other at the next Freeman's swap meet!

[71'tahoe]

Originally Posted by CarolinaHD

Nice steady progress I like it! Take lots of pictures when you replace the wheel cylinders, that what I have left next on my c50. I just finished up this hydroboost swap in my 67, came out of a 2007 c5500. Bosch hydro-max with a 2" bore master cylinder, just another option for this watching. Bolted right in no modifications except for the pedal push rod was cut down.

Did you get your hydroboost new or a used one from a donor truck? Thinking about this now I may rethink my choice and look for a C5500 hydroboost. One can never have enough braking for a big truck,especially since I plan to use this truck. I plan to take as many as I can. Seems it's easier to tell the story when you can add photos.

[71'tahoe]

Originally Posted by Campbel45

and 71'Tahoe great thread going so far! I've enjoyed the reading and pictures. I too would've moved onto the Kansas cab. We may see each other at the next Freeman's swap meet!

Thanks! I'm glad to hear my build is of interest to you. Sounds like a plan! I like meeting new people from the board.

[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