Looking for Ideas on replacing my single reservoir with a dual reservoir master cylinder but something that has balls to stop a 1.5 ton truck. Any ideas? Here is what I have now.
1942 Ford GPW 1943 Ford GPW T33 jet MD500 Little bird Helicopter 1940 LRDG WA truck 1940 LRDG WB truck
A hydrobooster and dual master cylinder from a late '90's thru early "2000's 1 Ton GM works well. The hydrobooster has the power to stop like "Now"!
Last edited by TUTS 59; 07/08/20251:41 PM. Reason: Add Images
~ Craig 1958 Viking 4400 "The Book of Thor" Read the story in the DITY 1960 Chevrolet C10 "A Family Heirloom" Follow the story in the DITY Gallery '59 Apache 31, 327 V8 (0.030 over), Muncie M20 4 Speed, GM 10 Bolt Rear... long term project (30 years and counting)
Come Bleed or Blister, something has got to give!!! | Living life in the SLOW lane
Hydroboost is the way to go. Hydrovacs are obsolete for medium-duty trucks and are getting hard and expensive to find. All you need is to add a power-steering pump to the engine.
Try to find a master cyilinder with a bore that matches your current one and you shouldn't notice any difference in pedal travel. Look for the chevrolet c3500-c6500 and the Ford f350-f550 trucks in salvage yards.
reggiis - If you do end up replacing the existing units, please don't trash them. They are super hard to find and there are some folks that would love to snag them as there are still a few rebuilders around to get them back to proper operation. That goes for the vacuum booster, master cylinder and even the vacuum lines and fittings.
You can offer to sell or give them away in the appropriate Swap Meet forum and help one or more fellow Big Bolters out.
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
It would be nice to find something off the shelf that I could buy new. Anything I could find at Autozone or another Car parts place would be great. I will keep the old stuff intacked so I can sell it to someone that wants it.
1942 Ford GPW 1943 Ford GPW T33 jet MD500 Little bird Helicopter 1940 LRDG WA truck 1940 LRDG WB truck
Your going to find that whatever Master Cylinder you use it will need a custom bracket. You may be able to adapt a bracket from a smaller series Truck. The larger Trucks don't have a lot of aftermarket part available.
For my project I started with a generic pedal bracket, it allowed me to position the pedal correctly. I had to Fab up a support bracket for the Hydrobooster. All of this is located under the floor, I have enough clearance to service the unit. The Hydrobooster on my Truck came from a 1990 GM Motorhome, it had 4 wheel disc brakes. The Master Cylinder is large enough to handle the volume required. Do some research, check out NAPA or RockAuto, you should be able to find something to fit you needs.
~ Craig 1958 Viking 4400 "The Book of Thor" Read the story in the DITY 1960 Chevrolet C10 "A Family Heirloom" Follow the story in the DITY Gallery '59 Apache 31, 327 V8 (0.030 over), Muncie M20 4 Speed, GM 10 Bolt Rear... long term project (30 years and counting)
Come Bleed or Blister, something has got to give!!! | Living life in the SLOW lane
Not knowing what your plans are for your project, I just want to say that my '57 2 ton truck loaded with 110 bales of hay probably weighed 11,000 - 12,ooo pounds, the stock brakes have no problem controlling the decent, I rebuilt the entire brake system with cylinder kits and a Hydrovac kit.
1957 Chevrolet 5700 LCF 283 SM420 2 speed rear, 1955 IH 300U T/A, 1978 Corvette 350 auto, 1978 Yamaha DT175, 1999 Harley Davidson Softail Fat Boy
Wow, that linkage vacuum booster setup is pretty unique. Even on this forum, I've never seen one before.. so you aren't going to have much luck, probably, finding something off the shelf. If you can find an old school NAPA that still has paper catalogs, you might get lucky on the master cylinder tho. The hard lines you can make yourself, the brake hoses can be sized up, or also custom made. Wheel cylinders you can probably find new or have sleeved with brass or stainless steel.
Leaving only the vacuum booster. Does it still work?
Wow, that linkage vacuum booster setup is pretty unique. Even on this forum, I've never seen one before.. so you aren't going to have much luck, probably, finding something off the shelf. If you can find an old school NAPA that still has paper catalogs, you might get lucky on the master cylinder tho. The hard lines you can make yourself, the brake hoses can be sized up, or also custom made. Wheel cylinders you can probably find new or have sleeved with brass or stainless steel.
Leaving only the vacuum booster. Does it still work?
No It does not..
1942 Ford GPW 1943 Ford GPW T33 jet MD500 Little bird Helicopter 1940 LRDG WA truck 1940 LRDG WB truck
Bummer :-( For this truck, I think the '90s Hydroboost would be the go-to option then.
If you'd like to keep it pure, for later show reasons or you just don't want to do the fabrication, there is this place.. https://www.brakematerialsandparts.com/booster-rebuilding I bet they could fix what you have to like new condition.
I can fab anything I need. I just hate having a learning curve when it comes to this truck. I'm stretched pretty thin when it comes to money because of all my WWII Jeep restorations I'm doing at the time.
1942 Ford GPW 1943 Ford GPW T33 jet MD500 Little bird Helicopter 1940 LRDG WA truck 1940 LRDG WB truck
I can fab anything I need. I just hate having a learning curve when it comes to this truck. I'm stretched pretty thin when it comes to money because of all my WWII Jeep restorations I'm doing at the time.
If time and money are scarce, rebuilding the existing system will be simpler than trying to cobble something together. You'll be back on the road way faster!
Hello Regg...if you get a second, watch this video. In it he explains the parts in the system and how the Hydrovac works. He recommends two shops, Prior Automotive in Texas and Power Brake Sales in Sacramento CA for the rebuild. I called the one in CA and she said they will rebuild them for just over $300.00. Said just ship it to them with your contact Information and no problem (916)446-7829. After watching the video I've decided to keep my truck stock and repair the system.
Hello Regg...if you get a second, watch this video. In it he explains the parts in the system and how the Hydrovac works. He recommends two shops, Prior Automotive in Texas and Power Brake Sales in Sacramento CA for the rebuild. I called the one in CA and she said they will rebuild them for just over $300.00. Said just ship it to them with your contact Information and no problem (916)446-7829. After watching the video I've decided to keep my truck stock and repair the system.
Just a quick follow up, I have the same 1 1/4" bore master cylinder in my 2 ton and was able to order a new (probably made in China, but who knows) MC from Partsgeek.com for $59.00. I think with shipping and tax it was around $80.00. Ordered it on a Saturday and it showed up today (Thursday). Got it installed and it fixed the problem I had which was making me think I needed to rebuild my booster. Anyhow, their part number is 355-47216.
Thanks for following up and giving the part number!
Here's a test if you want to be sure your booster is working.
1 - With the engine off press on the brake pedal a few times to insure there is no vacuum left in the system. 2 - With medium leg pressure step on the brake pedal and start the engine. 3 - If the booster is working you'll feel the brake pedal fade towards the floor as the engine builds vacuum.
