1966 GMC L4000 Tilt-cab brake parts

[Campbell]

Hi guys,

I'm hoping to get some help finding brake parts for my gmc L4000 tilt cab. I'm in search of a master cylinder and wheel cylinders. Attached is a few pictures of the SPID and master cylinder. I've got a Chevrolet parts book but I'm not having any luck finding the master cylinder.

This master cylinder seems unique in that the bore for the clutch is smaller than the bore for the brakes.

Thank you for the help.

[Campbell]

FYI, I believe I've found:
- Master cylinder: Centric 130.80018
- Front wheel cylinders: WC8852, WC8853
- Rear wheel cylinder: WC37095, WC37096

Still looking for:
- Brake lines
- Clutch line

[David R Leifheit]

Originally Posted by Campbell

Hi guys,

I'm hoping to get some help finding brake parts for my gmc L4000 tilt cab. I'm in search of a master cylinder and wheel cylinders. Attached is a few pictures of the SPID and master cylinder. I've got a Chevrolet parts book but I'm not having any luck finding the master cylinder.

This master cylinder seems unique in that the bore for the clutch is smaller than the bore for the brakes.

Thank you for the help.

There is the first problem, you have a Chevrolet parts book for a GMC.
Most autoparts stores, and their computer parts books, may think these trucks are the same, but the reality is that they are often not the same parts.
The master cylinder in the pictures looks like a standard GMC master cylinder.

Wheel cylinders would be the same situation (I have replaced mine in one truck and found this out). The Chevrolet part numbers might work for one, but not for both sides. The best bet is to get the numbers off the parts and find a cross reference for them.
What I ran into was that Chevrolet used the same wheel cylinder both sides on the rear, while GMC had a right and a left cylinder.

Brake lines/clutch lines would be a "bend it yourself" situation. I don't know of any outfit that makes reproduction lines.

[Campbell]

David, after not having luck with chevrolet book I figured I couldnt use it.

I'm not referring to hard brake lines. I'm referring to rubber lines. It seems that rockauto has the front and rear rubber lines. The clutch line is out of stock so I might just use a front brake hose and adapt it into the system.

[Campbell]

Guys,

I wanted to give an update. That Centric part number (130.80018) above is WRONG! Attached are a few pictures of the comparison. Based on my extended research, I am in need of part numbers: NMC P55385 (NAPA), 130.8002 (Centric), MC36347 (Raybestos), F54834 (Wagner). All of which are I believe obsolete. However, I did find an ebay seller that has new-old stock on bendix units that are exactly what I need. https://www.ebay.com/itm/224004132162

I will continue to update this until I have all new brakes. I hope it helps someone else down the road.

Thanks!