Specific brake booster for 1967 C30?

[BigTopGT]

I've been battling a brake issue for the last month and we're now questioning whether the truck should have a booster or not.

It went in for an exhaust install and a wheel cylinder replacement and now we're Pines, new master, and wheel cylinders into the escapades.

The shop is now suggesting a C30 needs a booster to leverage the brakes of the C30 vs that of a C10 and I'm not having a ton of luck finding a specific booster for it.

It's an 283 V8, 8 lug, coil spring setup, if that matters.

If anyone has some advice, I'd appreciate it to the moon.

Pic of truck for discussion.

[michael bustamante]

So if youre running a big block more than likely the nooster will be small but fatter to accomodate the left valve cover issue,
co traditional c-10 booster are most likely not what youre needing

[BigTopGT]

Originally Posted by michael bustamante

So if youre running a big block more than likely the nooster will be small but fatter to accomodate the left valve cover issue,
co traditional c-10 booster are most likely not what youre needing

It's a 283, so I don't think the space is an issue, thankfully.

If a c10 booster will work, that'd be a win.

[too much stuff]

Looks to me like it is a C-20 and not a 30. That may help your search.

[BigTopGT]

Originally Posted by too much stuff

Looks to me like it is a C-20 and not a 30. That may help your search.

Thanks!

How can you tell, because it's got C30 badges on the fenders (came like that from the previous owner), so I assumed it was actually a 30.

[jocko]

I think your shop is trying to create business for themselves. If I recall, I don't think GM mandated power brakes on 3/4 ton + until 71-ish(??) But not sure off the top of my head. Regardless - it's not a bad idea to add power brakes, but your manual brakes would and should work just fine.

But, if you opt to upgrade - these two gents sell parts that may be able to help you (make sure to let Frank (Pickmup) know your application is for a 67 C20/30):
Pickmup https://67-72chevytrucks.com/vboard/...d.php?t=581862 FULL power brake system, soup to nuts
Captainfab https://67-72chevytrucks.com/vboard/...d.php?t=347484 Bracket for adding a booster to a manual brake truck using off the shelf parts store boosters and parts.

Both gents sell the highest quality stuff you'll find - I've purchased from both of them.

[HO455]

Has the shop determined what size bore your current master cylinder is? How does it compare to the wheel cylinder bores.

It's quite possible that the master cylinder was replaced with the wrong sized bore for manual brakes?

And or you have the wrong ratio for the pedal.

https://grassrootsmotorsports.com/fo.../195255/page1/

https://techtalk.mpbrakes.com/how-to...<br /> master.

Here is some math that may help you.

https://www.motionraceworks.com/page...d-calculations

I don't know what shop you have had the truck at but personally I've never had good luck with shop's when it comes to brake modifications. Most just want to swap your parts to parts they're comfortable with. Doing the research and calculations has always worked better for me.

Good luck and please post your findings.

[BigTopGT]

Originally Posted by HO455

Has the shop determined what size bore your current master cylinder is? How does it compare to the wheel cylinder bores.

It's quite possible that the master cylinder was replaced with the wrong sized bore for manual brakes?

And or you have the wrong ratio for the pedal.

https://grassrootsmotorsports.com/fo.../195255/page1/

https://techtalk.mpbrakes.com/how-to...<br /> master.

Here is some math that may help you.

https://www.motionraceworks.com/page...d-calculations

I don't know what shop you have had the truck at but personally I've never had good luck with shop's when it comes to brake modifications. Most just want to swap your parts to parts they're comfortable with. Doing the research and calculations has always worked better for me.

Good luck and please post your findings.

Honestly, I think all that's been done is buying parts from local auto parts stores based on what their computers say to buy.

I'll have to see if I can find the sizes of each to compare asap.

[dagnabbitt]

I'd post a pic of the SPID or VIN to answer the C20/30 question. At this point if it were me I would be considering the above soup to nuts suggestions: sounds like there is a lot of nickel and diming going on with your parts and repairs.

[BigTopGT]

Originally Posted by dagnabbitt

I'd post a pic of the SPID or VIN to answer the C20/30 question. At this point if it were me I would be considering the above soup to nuts suggestions: sounds like there is a lot of nickel and diming going on with your parts and repairs.

Good call.

I'll post the vin when I'm get to the truck in the morning.

[MJN]

coil spring setup- if rear coils its a C20, standard equipment for a C/30 was leaf springs
J70 vacuum power brakes were an option- manual brakes were standard
https://www.gm.com/content/dam/compa...olet-Truck.pdf

[MattG]

I have a 67 C20 with 283 and my uncle has a 69 C30 with transplanted 350 (and massively huge Franklin camper shell). I put the same CPP booster/mc setup in both trucks several years ago (mine in 2013 and his in 2014) and both stop very well. Both trucks still have their original drum/drum brake setups. The CPP model is 6772BBD-11. Oh and my C20 is coil spring front and rear, his C30 is coil/leafs.

[1967GMCC20]

CPP had a huge display at a large car show in KY. I was impressed at the complete packages they have for trucks and cars.

Previous Owner put a nice Hydroboost on my 67.