1951 front rubber hose from master cylinder

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1951 front rubber hose from master cylinder

Post by gdestephano » Thu Dec 21, 2017 1:01 pm

Hope someone out there has come up with a better idea before I replace the rubber hose. My 51 master cylinder has a slip on rubber hose over the facing front smooth barb with no hose clip which allows for hose movement.
This hose runs under the motor half way then connects to the metal brake line (hose slip on connection) which attaches to the rubber presser hose line going to the brake wheel cylinder. Is this really stock or did some genius hacked it for a quick fix? It looks like I could unscrew the barb and switch over to something a brake line could attach to. Any thoughts on this before I do my genius change?

Dave Czirr
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Re: 1951 front rubber hose from master cylinder

Post by Dave Czirr » Thu Dec 21, 2017 1:45 pm

If I understand your description correctly, sounds like some mongrel did a Goldberg.

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Re: 1951 front rubber hose from master cylinder

Post by Howard56 » Sun Jan 07, 2018 11:30 am

There are only 3 rubber hoses on the brake system. One at each front wheel and the third from the steel line on the left frame rail dropping down to a brass block on top of the rear axle. There are a few sections of rubber hose slipped over steel tubing as protection but none of those hoses carry pressure directly.

The master cylinder should have a multi port brass Y shaped block on the end. It is held by a hollow bolt with copper sealing washers on each side of the block. One port of the block goes to the pressure switch, another to the line feeding the rear wheels and the third port to a short tube connecting to another brass block mounted on the frame near the left front wheel. Some years it was on top and others on the side of the frame. From that second block a short tube connects to the hose going to the L wheel and another longer U shaped tube attaches to the rear side of the front crossmember and feeds the right hose and wheel. On some earlier models with masters farther away from the steering box there are only two ports for the tubes on the brass block and the brake light switch is threaded into the end of the hollow bolt.

Packard didn't publish a drawing of the 51 plumbing layout but this one from the 55 manual is representative of the routing of the 51 lines. It shows a power brake setup so the tubes are different shaped but the 51 manual master is almost in the same location. The master cylinder photo is of a 51.

EDIT: Has been a lot of years since I looked at a 51-4. Was just thinking there is a possibility that instead of the second brass block on the frame and the right wheel tubing coming off from that second block as was done on most years, the multi port block on the end of the master is used instead. The tube to the right front wheel may come off the end of the hollow bolt where the brake light switch was located in earlier years or there may be a fourth port on the block. At any rate there is no rubber hose at the master and never a hose secured on a barb fitting with a hose clamp anywhere in the brake system. You can easily reach 6-800 psi or more in the brake lines so a hose clamp and barbs could not hold that. The way the metal tube is clipped to the front cross member it is vulnerable when pulling the engine. It is possible the tube was crushed or broken and someone elected to repair it with the rubber hose you found. Definitely not a good idea and an accident waiting to happen.

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