Brake Box? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Benelli · 05-16-2010, 01:10 PM

Under the radiator, there's a box that the brake lines run to and from. What is this part called?

Scootin 81 C20 · 05-16-2010, 02:04 PM

Sounds like it could be very early ABS, but I'm not sure.

Prong · 05-16-2010, 05:08 PM

Proportioning valve (or combination valve in some circles).

*78 Chevyrado* · 05-16-2010, 05:40 PM

Quote:

Originally Posted by Prong

Proportioning valve (or combination valve in some circles).

x2

81ratrodc10 · 05-16-2010, 05:44 PM

Quote:

Originally Posted by 78 Chevyrado

x2

x3

Benelli · 05-16-2010, 08:25 PM

Quote:

Originally Posted by Prong

Proportioning valve (or combination valve in some circles).

Alright. Here's the Real question.

I just replaced my master cylinder, and the brake booster is claimed to be only a few years old (I fairly trust the guy I bought the truck from).

My brakes are still pretty sprongy, especially when pulling something. And things can get a little hairy pulling. Would these cause spongy brakes, and are they even available to buy or rebuild one?

73chevyman · 05-16-2010, 08:48 PM

sounds like you need to bleed the lines and rid of the fluid....

Turbo85GMC · 05-17-2010, 07:19 AM

Quote:

Originally Posted by Benelli

I just replaced my master cylinder...

Did you bench bleed the new master cylinder? Haven't replaced one myself, but I've heard/read from several people on the board that you have to bench bleed them. Just an idea.

Benelli · 05-17-2010, 10:04 AM

Quote:

Originally Posted by 73chevyman

sounds like you need to bleed the lines and rid of the fluid....

I did that after I got it replaced.

Benelli · 05-17-2010, 10:05 AM

Quote:

Originally Posted by Turbo85GMC

Did you bench bleed the new master cylinder? Haven't replaced one myself, but I've heard/read from several people on the board that you have to bench bleed them. Just an idea.

Nope, I sure didn't. Didn't even know what bench bleeding was before I read this.

**N2TRUX** · 05-17-2010, 11:03 AM

It sounds like you still have air in your lines. You can gravity bleed them, but that takes forever. I have a trick that works pretty good. It does require two people to do.

I use the traditional method of bleeding with a twist. I have a piece of vacuum, line that fits over the bleeder valves. I run this down in to a half full bottle of fluid. Put your line wrench on the valve, then slip the hose hose on and run it in to the bottle.

Now get your partner to pump the brake and hold. Then open the valve till the pedal goes to the floor pushing air and fluid out. Close the valve and repeat. The difference with this method is you capture the fluid, and since the hose is submerged it won't allow air to be drawn back in the line.

This method has worked great for me...

73chevyman · 05-17-2010, 02:37 PM

thats a pretty cool trick

Benelli · 05-18-2010, 12:23 AM

I guess I'll add it to the list of "Crap to do"

Thanks guys, always appreciate good quick honest answers.

05-16-2010, 01:10 PM	#1
Benelli Watchin the rust grow Join Date: Oct 2008 Location: Western Nebraska Posts: 950	Brake Box? Under the radiator, there's a box that the brake lines run to and from. What is this part called? __________________ 1979 Chevy K10 (H/D Front end) - 350 w/ Holley Truck Avenger, Weinald Intake manifold, headers, bored .060 over, mild cam, Built up TH350 (TranStar Shift kit) with a part-timed NP203 t-case SOLD ($3,000) 1997 Chevy Silverado 1500 - 4.3 vortec, extended cab, 21 highway MPG, stock. "Red" SOLD ($3,000) 1987 Toyota 4wd Pick-up - work in progress, future DD SOLD ($1,850) 1998 Dodge Ram 2500 Cummins 5spd Quad cab - old 12 valve with some work done 2004 Chevy Silverado - Black, 4x4, 5.3L, stock for now Underneath that rust is a heart of gold

05-16-2010, 02:04 PM	#2
Scootin 81 C20 3/4 Ton Rodder Join Date: Jan 2009 Location: Manlius, IL Posts: 1,146	Re: Brake Box? Sounds like it could be very early ABS, but I'm not sure. __________________ 1981 Chevy Scottsdale C20 "Orange Crush": SOLD 1989 Chevy Silverado K2500: All Stock (For Now), 350 TBI/700R4. DD/Light Duty Toy.

05-16-2010, 05:08 PM	#3
Prong Registered User Join Date: May 2007 Location: CO Posts: 475	Re: Brake Box? Proportioning valve (or combination valve in some circles).

05-16-2010, 08:48 PM	#7
73chevyman Registered User Join Date: Nov 2008 Location: Lusby, MD Posts: 563	Re: Brake Box? sounds like you need to bleed the lines and rid of the fluid.... __________________ http://67-72chevytrucks.com/vboard/group.php?groupid=37 73 C10 Fleetside If it ain't a Chevy it's foreign http://hotridesmag.com/

05-17-2010, 11:03 AM	#11
N2TRUX Happy to be here Join Date: Mar 2000 Location: Cypress, TX Posts: 39,021	Re: Brake Box? It sounds like you still have air in your lines. You can gravity bleed them, but that takes forever. I have a trick that works pretty good. It does require two people to do. I use the traditional method of bleeding with a twist. I have a piece of vacuum, line that fits over the bleeder valves. I run this down in to a half full bottle of fluid. Put your line wrench on the valve, then slip the hose hose on and run it in to the bottle. Now get your partner to pump the brake and hold. Then open the valve till the pedal goes to the floor pushing air and fluid out. Close the valve and repeat. The difference with this method is you capture the fluid, and since the hose is submerged it won't allow air to be drawn back in the line. This method has worked great for me... __________________ Follow me on Facebook and Instagram @N2trux.com Articles- "Jake" the 84 to 74 crewcab "Elwood" the77_Remix 85 GMC Sierra "Scarlett" "Refining Sierra"

05-17-2010, 02:37 PM	#12
73chevyman Registered User Join Date: Nov 2008 Location: Lusby, MD Posts: 563	Re: Brake Box? thats a pretty cool trick __________________ http://67-72chevytrucks.com/vboard/group.php?groupid=37 73 C10 Fleetside If it ain't a Chevy it's foreign http://hotridesmag.com/

05-18-2010, 12:23 AM	#13
Benelli Watchin the rust grow Join Date: Oct 2008 Location: Western Nebraska Posts: 950	Re: Brake Box? I guess I'll add it to the list of "Crap to do" Thanks guys, always appreciate good quick honest answers. __________________ 1979 Chevy K10 (H/D Front end) - 350 w/ Holley Truck Avenger, Weinald Intake manifold, headers, bored .060 over, mild cam, Built up TH350 (TranStar Shift kit) with a part-timed NP203 t-case SOLD ($3,000) 1997 Chevy Silverado 1500 - 4.3 vortec, extended cab, 21 highway MPG, stock. "Red" SOLD ($3,000) 1987 Toyota 4wd Pick-up - work in progress, future DD SOLD ($1,850) 1998 Dodge Ram 2500 Cummins 5spd Quad cab - old 12 valve with some work done 2004 Chevy Silverado - Black, 4x4, 5.3L, stock for now Underneath that rust is a heart of gold



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.