Hard Pedal, No Brakes

Q.

I have a 1962 Ford F100 with a new master cylinder installed. No leakage. All manual drum brakes. No booster. Hard brake pedal, but no fluid going to the wheel cylinders, even with bleeders completely removed on all four wheels. I can’t bleed the brakes. Any suggestions? I have bled many brakes in prior years on various vehicles, but never encountered this. This truck sat for three years before I recently purchased. Thank you for any assistance.

A.

Assuming you still have the original single reservoir master cylinder, I suspect there is either a clog in the line before the splitter or a clog in the splitter or your new master cylinder is faulty (it happens, even with new parts). I would start at the master and loosen the line fitting, put on safety goggles, wrap a rag around the fitting, and have someone press the brake pedal. If fluid is present and the pedal travels to the floor then the culprit is likely a clogged line. Then loosen the line at the splitter and repeat fluid check process, then check the lines as they leave the splitter. We are only trying to discover the source of the obstruction at this point and are not concerned with bleeding the system.
At this point you should have a good idea of where the problem resides; clean and/or replace the affected component, then proceed with bleeding the brake system.

I recently encountered a similar problem on a 1968 Cutlass. The car had been converted to a dual reservoir master cylinder at some point and the owner complained about a lack of brakes, although the brake pedal was hard. We went to bleed the rear brakes and no fluid was present, and even with the rear bleeders removed, we still had a hard pedal. The Master Cylinder was only a year old, so we found it hard to believe it could be the source of the problem… but we removed the line from the master, held a rag over the open port (wearing safety goggles), and had someone press the brake pedal to determine if fluid was passing through the master. To our surprise, we still had a firm pedal and only a drop or two of brake fluid came out of the port. We replaced the master cylinder, then everything worked perfectly.

Wrench Safe,

-Mark

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15 Responses to “Hard Pedal, No Brakes”

  1. Ken Duda

    Possible collapsed brake hoses going to the front wheels and the one going to the rear. If they are deteriorated fluid will not flow to the brakes.

  2. Bob Graham

    A couple of things…. 1. Flex lines can swell internally over time and restrict flow of fluid to the wheel cylinders/calipers ( although this normally won’t allow the brakes to release) 2. I’ve recently had a remanned caliper right out of the box have the inlet plugged with steel shot from the cleaning process at the rebuilding shop.

  3. Matt

    I had same issues and found rubber lines inside lining collapsed . Any rubber lines in a brake system I now change every ten years or 100,000 miles

  4. Johnmloghry

    Had the same problem many decades ago on a 1958 Olds Fieste wagon. Turned out to be a clog at the splitter. Rebuilt all wheel cylinders anyway. Flushed the system with new fluid. Problem solved.

  5. Johnmloghry

    This happened to me back in 1968. I had a 1958 Olds Fieste station wagon. The person I bought the car from had recently replaced the air suspension system with coil springs and new ball joints then the trans went out, it was the wife's car so while it was in the shop getting the trans rebuilt she bought a new car. They parked the Olds in the front yard and tried to sell it but had no takers, probably because it was pink and black. The husband was a carpenter and was working on a job with my dad. My dad mentioned that I needed a car, so the man told him he would sell me the Olds for $50.00. We went to see the car put a new battery in it, fired it up and I bought it. I guess I had the car for 6 months then the brakes started getting hard to push and had very little stopping power. I didn't know much so I replaced the power booster thinking that was the problem, but it didn't solve the problem, so I replaced the master cylinder, didn't help, next all four wheel cylinders they wouldn't bleed. I was totally baffled so I finally took it to a mechanic who blew out the lines with air pressure added some kind of drying chemical, bled the brakes and finally I had great brakes.

  6. tbroyan

    I have a 1941 International Harvester K2 pick up truck. My father-in-law learned how to drive in that very truck when he was about 10 years old. When I became the owner of it (only the fifth since new) I was giving it the once over just for grins and found when I was replacing the brake fluid that the right rear wheel cylinder wouldn't bleed out. After going over the brake lines I found a nail in the brake line using the head to plug off what turned out to be a leaking wheel cylinder. I guess and old farmer trick to keep it going and still have some brakes at least. In any event even if the brakes seem to be fairly functional it's not a bad idea to go over every inch, inside and out to make sure something "creative hasn't been done in the past.

  7. Josh

    Replaced MC (forgot to bench bleed) and a couple of wheel cylinders on a 1964 F250 w/drum brakes. I used a vacuum pump to bleed brakes and the fluid looked pretty good. But there is little to no pressure being built up with the brake pedal. Is it the failure to bleed the brake MC or am I just impatient?

  8. Richard Cotton

    If in the process that was suggested by one of the other responders if no fluid comes out of the master cylinder it is possible that the residual pressure check valve was installed backwards.

  9. Joe Jendresky

    Great question and very informative. I planned on replacing the brakes on my mustang this winter. This could save me a lot of time.

  10. Keith

    Former ASE Master Tech, I have a truck just like yours. I would start at the flex hoses at both front wheels and at the rear axle. These old hoses are prone to come apart on the inside and clog. Open each line (using caution) and try the brake pedal each time a line is opened. Then work your way back to the master cylinder until you are satisfied finding your stoppage, them replace parts as necessary. I would also suggest that if all of the original hydraulics ( master/wheel cylinders, hoses and even the hard lines be replaced as there is no way to inspect these parts from the inside) they may look good on the outside but you never can tell and if you are staying with a single pot master cylinder, any part that fails will leave you without brakes!