The Stovebolt Site Forums The Parking Lot Big Bolts master cylinder for 48 gmc fc303

Well, we got the old beast working under her own power. Now it's time for the brakes. First - master cylinder.

And the same problem as usual. All the master cylinders on parts websites are for the smaller pickups. Ours is in the cab of the truck. Anybody know parts numbers, rebuild kits or anything like that?

We've got a few numbers off the cylinder: 361-k and 5450930 a2

The plunger measures 1 1/4 diameter.

any help would be great

The part No. is 5450929 and was used in all 3/4-1-1 1/2+ 2 ton trucks Chevy and GMC 1947-52 1/2 ton is different.

the napa catalog shows 9221 w/booster & 9220 wo/booster. Thats 3/4 ton.

Yep! that's it. found it at the local Napa Superstore. The last one in stock.

So, since we're on the brake topic, our next step is the pedal return spring and the brakes themselves. Does anybody know of the brake pedal return spring? Can I assume it was the same spring used on pickups?

And I see on the sites that they sell brake parts for larger (1 1/2 ton) trucks like ours, but they're for 51 and newer. Is there any difference between these and our 48? We haven't taken any brakes apart yet. So we don't know what's up with them... other than not having moved in 30 years.