WHERE DID THE FLUID GO?

By Classic Car Restoration Club Editors

QA-53Chevy-1

Q:

I have a 1953 Chevrolet pickup. Since I have not had much time or money to work on the old truck, it just sits in my backyard. Recently, I moved it, and when I tried to use my brakes, it seemed as if the master cylinder was dry. I know it is hot out here in Phoenix, AZ, but can this cause the brake system to go dry? Do you have any ideas on how to cure this problem without spending a lot of money? I’m on a tight budget. Andrew McLemore Phoenix, AZ

A:

The reason master cylinders go dry is a leak in the system. It’s a closed, sealed system, so brake fluid would have no way to evaporate from heat. A good course of action would be to fill the master cylinder with brake fluid, and then have someone slowly pump the brake pedal while you explore where it may be leaking. Common leak-prone areas include the back of the master cylinder or any of the four wheel cylinders. You’ll also want to check all of the brake lines as well. Often, the culprits here are the swaged flex lines near the front wheels, or the flex line to the rear axle. Once you know exactly where the leak is, you’ll have a better idea on what needs to be done to fix it. Here’s a note of caution though, protect your eyes when looking for brake fluid leaks! That stuff really hurts if it gets into your eye. If you don’t immediately flush it out it, it can even cause permanent damage. So, be careful, and good luck! Mark Simpson Managing Editor

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16 Responses to “WHERE DID THE FLUID GO?”

  1. Don Baney

    If that master cylinder is under the floor like the cars were look closely there. Had 53 and 54 when growing up. Those caught all the salt and road grime and rusted badly

  2. Smith

    looking 👀 foward to getting the information

  3. Robert

    Whatever you do on a vehicle, wear approved safety glasses, because everything you do regarding the repair of a vehicle can potentially cause damage to your eyes. That includes work you do repairing parts on or off the vehicle. I have a sign on my garage wall that says "Safety First".

  4. Bruce Grout

    Just food for thought, I've experienced this condition with older (70's) brake booster vehicles. I've found the rear compartment of a dual chamber master being drained empty (front chamber stays full) due to the booster vacuum drawing the brake fluid out and into the booster. However to fill a booster with enough brake fluid to get drawn into the intake to cause smoke would require several bottles full of fluid to have been added without checking why..! If the master in question is a single chamber this could still happen, but only if it also has a vacuum booster attached.

  5. Tony Williams

    These questions are several years past. I doubt my reply would be of any use to the fellow

  6. Frank Novisku

    Wear safety glasses when do this Inspection.

  7. Aaron Killian

    These old chevys love to leak at wheel cylinders

  8. JOHN SNIGIER

    Often the fluid leaks out on these vehicles during periods of non-use because the fluid leaks past the lips of the piston cups of the wheel cylinders and/or the Master Cylinder when residual pressure is lost. Some hydraulic brake parts manufacturers make new cylinders and/or rebuild kits with special springs and expanders to keep the lips in contact with the bores. EIS Brake parts was a pioneer in this field. Look for parts/kits with cup expanders inside. Peeling back the dust boot on the cylinders will usually reveal where the leak is.

  9. Tom

    I think I read all the comments. If the reservoir was empty, and you can't find a leak, then I think someone mentioned that it may be leaking into the booster. If you basically had no brakes, but the reservoir still had some fluid, it is possible to fail the internal MC seal. That will prevent a pressure build also. This happened to a car I had sitting in the garage for a few years. The internal seals were basically destroyed.

  10. William

    1991 ignition replacement on jeep yj