I’m going to try to take a brake fitting and weld it shut to make a plug. I’ve spent months trying to find a “made for it” plug with no luck. Anyone have any input on the idea? I’ve already welded them up but haven’t installed. All possible solutions are welcome. I want this on the road in the spring.
Show me a picture of where you need a plug...I'm confused. Is it on the Hydrovac or wheel cylinder???
Chris - In looking at your pictured wheel cylinders, I can't see what "port" you are trying to close up on them. I have an exploded brake diagram of your style setup below from a Chevrolet Truck Special Illustration book. The only added port plugs in that diagram appear to be the early style 2 piece bleeder valves. They were made up of a valve with a threaded hole for a 10-32x1/4 machine screw and washer to close the valve port. Later one piece bleeders (with the nipple for attaching a hose) have become the replacement for the old 2 piece valve.
EDIT: Mike B beat me to the post button. Leaving my post up in case the picture helps.
Last edited by Gdads51; 03/08/20254:33 AM. Reason: add edit note
~ 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)
On the wheel cylinder there is a place for the brake line to come in, a bleeder port, and a port for the jumper between the wheel cylinders. One cylinder brings in the brake line and has a bleeder and the jumper.( All ports are used). The second wheel cylinder has a bleeder and the jumper but there is no incoming line. This would need to be blocked off or your brake fluid would pour out.
On the wheel cylinder there is a place for the brake line to come in, a bleeder port, and a port for the jumper between the wheel cylinders. One cylinder brings in the brake line and has a bleeder and the jumper.( All ports are used). The second wheel cylinder has a bleeder and the jumper but there is no incoming line. This would need to be blocked off or your brake fluid would pour out.
I see the problem now...your truck needs two different wheel cylinders on each side of the truck. The Rear, Front cylinders should have 4 tapped holes while the Rear, Rear cylinders should have 5 tapped holes.
Group 4.665
1951-52 Utility...Rear, Front...cast number 5453825-4...p/n 5453866.
1951-52 Utility...Rear, Rear...cast number 5453825-5...p/n 5453865.
If you look both of these part numbers up on the big auction site you can see the difference and they are available. The hole you're trying to plug isn't machined on the 5453866 part. Buy two of the correct cylinders and your problem is solved.
"I was looking for a way to spend more money!" ..so I went out and cast my gaze upon the ole' Big Bolt :-D (That always helps me find a way to spend any money I feel needs spending)..
I guess I’m spending more money while the wife is out of town. But to clarify, all the old wheel cylinders had the same part number on them, even though the rear front ones were “missing” a hole. Odd.
They are the exact same casting (front and rear), they got a -4 or -5 for the part number (stamped on the box) to differentiate between the 4-hole and 5-hole.
If you can't fabricate 1/2" steel lines and don't want to use 1/2" copper, you could use 1/2" PEX tubing, easy to work with, inexpensive, won't collapse under vacuum.
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
Don't forget to install the vacuum check valve high on the firewall. It protects the Hydrovac and 2-speed rear (if you have one) if you should backfire through the carb.
The valve you need is Group 4.955 p/n 2214107...there's a coupe on the big auction site now...
~ 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
If you can't fabricate 1/2" steel lines and don't want to use 1/2" copper, you could use 1/2" PEX tubing, easy to work with, inexpensive, won't collapse under vacuum.
Is the line at the HydoVac unit the only one that is broken?
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
As far as I can tell. The other end at the check valve seems to be good. I’d like to change out the whole line for safety. I’m concerned about finding a connector for the hydrovac side since it looks like a big double flare.
It should be a 1/2" inverted flare, that is the same as brake line nuts, fuel line nuts, Napa should be able to help round one up or check Dorman parts online and get the part number. Edit- Dorman does not list a nut for 1/2 inch tube, McMaster-Carr has one but the price is stupid. Can you salvage the tube nut and fabricate a new nipple from soft copper, it only needs to be long enough to clamp some 1/2 inch hose on it. You could also remove the brass inverted flare x male pipe thread street 90, then you could use pipe thread fittings in place of the inverted flare. If you go that route, don't get too crazy when you tighten the pipe fitting into the cast aluminum HydroVac housing, it could crack easily.
Last edited by 78buckshot; 03/31/20259:53 PM.
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
Just a picture to clarify my Hydrobooster setup. This is only meant to show the actual mounting of the booster and dual master cylinder.
~ 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
