From: MasterBlaster on

TomO wrote:

> Following the hydraulic line from the master cylinder brings me to the
> part in question. This is a large cylindrical device about six inches in
> diameter with a narrower neck coming off the front of it. The neck feeds
> into a rubber tube that ends at a breather of some sort mounted on the
> firewall. There is a bleeder for the brake system in the narrow neck as
> well, and the brake lines come off of there too.
> There is also a feed from this device to the hydraulic pump for the dump
> bed on this truck, but I don't believe that the system shares the fluid
> between the brakes and the dump hydraulics.
> I got the brakes working well, but I'm still baffled by the purpose of
> this rather large device in the middle of the system.
> Any ideas?

Wanna bet someone here will know?

From: cuhulin on
I like that website,MasterBlaster.Thanks for posting it.

From: Steve on
TomO wrote:

> On Sat, 28 Apr 2007 17:14:08 -0500, cuhulin wrote:
>>Sounds like it is a brake booster to me.Look them up on the net.
> No vacuum lines to it though. My Google searches have been fruitless so
> far. Have you got any search terms that may find this part?
> I've tried 1951 GMC farm truck brake systems and a few other variants. No
> luck for me yet.
> I think it is not a booster, but who knows? I've been wrong before.

Could just be an air vent and filter for both the hydraulic and brake
systems, placed high enough that water from off-road work doesn't get
into the system.