Brake question on the '70 Country Squire

Discussion in 'General Automotive Tech' started by retropia, Jun 2, 2014.

  1. retropia

    retropia Well-Known Member

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    Here is the symptom -- I'm stopped at a light, and periodically the car acts like it wants to creep forward a bit, so I have to press a little harder on the brake pedal. The fluid level is fine and there are no obvious leaks around the wheels.

    It otherwise seems to stop fine, i.e., a hard stop works just like it always has.

    I'm thinking perhaps the master brake cylinder or maybe the power brake booster, and/or maybe a vacuum leak to the power brake booster. Thoughts? I've got an appointment to take it to the mechanic Tuesday morning.

    Also, is it a good idea to have the brake fluid flushed at the same time as they do whatever else it is they're going to do with the brakes?
     
  2. Silvertwinkiehobo

    Silvertwinkiehobo "Everything that breaks starts with 'F.'"

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    If the pedal begins to sink, the M/C seals aren't holding pressure, so it would eventually need replacement. My '79 Ranchero GT had that problem when I first got it.
     
  3. Junk

    Junk Well-Known Member

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    Boosters are pretty much black or white. They either work or they don't. Occasionally, you get one that has a torn bladder, and it will still function, but will give you a rough idle.
    The master cylinder is failing. I suggest that you have all wheel cylinders rebuilt, and the master cylinder, and that way, you will know that you have a good working system, with all fresh fluid in it. You should also consider replacing the 3 flexible rubber brake lines at the same time. If you need new brake shoes, now is the time to do this also. It will be expensive if you can't do your own work, however, safety is an important part of owning one of these cars.
     
  4. jaunty75

    jaunty75 Middling Member

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    Are you sure this is even a brake issue? When your foot is off the brake but you're not stepping on the gas, what happens? Does the car idle at a fast enough speed that you'd be cruising down the road at 15 or 20 mph? This may be a problem fixed by adjusting the idle speed.

    My '67 Delta 88 does this sometimes. I've never tried to fix it because it happens rarely, and the engine otherwise runs fine.
     
  5. retropia

    retropia Well-Known Member

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    I had the master cylinder replaced once since I bought the car, and I think I had the wheel cylinders rebuilt and rubber hoses replaced at the same time. But that was shortly after I bought the car, and I've had it for 24 years. So, it has been a long time. I'll have the mechanic look at everything in the braking system.

    The idle speed seems fine; it is slow and steady. The car doesn't move or barely moves when I take my foot off the brake.

    Thanks for the suggestions!
     
  6. retropia

    retropia Well-Known Member

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    Well, I dropped the wagon at the shop this morning, and the owner gave me a ride home in the wagon while testing the brakes. He doesn't think there is anything wrong with them. He feels the brake pedal should be moving more than it is when the car is stopped, if something was wrong with the master cylinder.

    The way we left it is that they are going to do a brake fluid flush and fill, and give the braking system an examination, to see if there is anything obviously wrong. Then I will pick it up and drive it for awhile, to see if that makes an improvement.

    On the one hand, I'm glad if there really isn't anything wrong with the master cylinder. On the other hand, the brake pedal doesn't feel "right" to me.
     
  7. BPinsent

    BPinsent Well-Known Member

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    I had the exact same issue with my '67 Ranch Wagon a few years ago, turns out they simply needed adjustment as the shoes had worn down enough that you needed to put more pressure on the pedal. It seemed to be worse after a lot of use within a short period of time.
    After the adjustment they were fine. Just recently it started happening again but I have decided that since the shoes are at least 10 years old that I install new ones on all corners. Good luck, hope that it is something simple.
     
  8. retropia

    retropia Well-Known Member

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    Heard back from the shop late this afternoon. After giving it a thorough examination, they found a lot of rust in the system. They recommend replacing the master cylinder, calipers, rear brake pads, proportioning valve, resurfacing the drums, rebuilding the wheel cylinders, replacing the rear grease shields, and flushing the old brake fluid. Estimate: $1,200-$1,500.

    They said the front brake pads look ok, the brake lines are solid, and the rubber brake hoses are good. (I remember we replaced the rubber brake hoses at some point in the past.)

    They said the old brake fluid gathers moisture and the car isn't driven enough to burn it off, which makes sense. I asked about going with synthetic brake fluid, and they thought it would work fine. Should I have any concerns about switching to synthetic?

    I wasn't anticipating it would need quite that much work, but on the other hand, there have been long periods where it hasn't been driven. Looking through my notes, there hasn't been any major brake work done since I've owned the car. So, it's not a complete surprise, either.

    There is a little sticker shock accompanied by nausea and being light-headed. Such are the occasional joys of old-car ownership.
     
  9. Junk

    Junk Well-Known Member

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    It is late, and I am tired, but I will ask you to hold off a couple of days till I can respond fully. I believe that the shop is going to be taking you over the hurdles. None of this is so difficult that you can't do it yourself, and save about $800 over what they are estimating. Go to Rockauto.com, and look up what all new parts are going to cost, before you even think of giving them the job. Brakes are not that difficult, if you know how to use some basic hand tools. Junk
     
  10. retropia

    retropia Well-Known Member

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    About the only brake work I don't mind doing is replacing disc brake pads, and I have done that on a few of my cars over the years. Of course, that is the one thing that doesn't need doing on the wagon. I've replaced drum brake pads once on a car, and didn't like doing it.

    I am thinking about investing in one of those power bleeders so that I can change the brake fluid by myself. I haven't started researching to see what is available. Does anyone have any opinion on these devices?

    Doing more research into brake fluid, it appears there is conventional (DOT 3, 4 and 5.1) or silicone (DOT 5). The conventional absorbs water, while the silicone does not. However, water can still get inside a brake system with silicone fluid, and since it is not absorbed by the fluid, it can puddle somewhere, still causing corrosion.

    So, I'm thinking the best solution is to continue using conventional brake fluid but learn how to flush it myself, once a year or every other year. Opinions?
     
  11. retropia

    retropia Well-Known Member

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    I forgot to mention that the shop is working on putting together a detailed estimate, at my request, before I agree to proceed. They have located most of the parts, but are having trouble finding the proportioning valve.
     
  12. Silvertwinkiehobo

    Silvertwinkiehobo "Everything that breaks starts with 'F.'"

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    They are getting scarce. One of my good customers has a '67 Cougar that my boss was able to get an O-ring kit for rebuilding the valve, with me doing the cleanup and rebuild on my own time as a courtesy for the customer, as, all told, just the cleanup and resurfacing the bore with crocus cloth to where the piston properly moved was about an hour and a half by hand. The brake warning switch is still available for fullsize '80s Fords, IIRC.
    A member of Fullsizebronco.com needed a prop valve for his '79 Bronco, and none were to be had for it; he ended up having to make new lines to adapt an '80s F-series valve to his system.
    It's interesting to note that, even with all the older cars and trucks getting restored and put back on the road, no aftermarket company rebuilds these important valves, let alone making new ones.
     
  13. retropia

    retropia Well-Known Member

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    The shop has found a proportioning valve, and is going to charge me $129 for it (not including labor). I don't know what brand it is, if it is NOS, rebuilt, or reproduction.

    Here is one I found on eBay that claims to be a fit for $75:

    1960-70-Mustang-Fairlane-Galaxy-Proportioning-Valve-Disc-Drum-With-Residuals

    It's hard to know if it would actually work for my car or not until you actually purchased and installed it.
     
  14. retropia

    retropia Well-Known Member

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    They faxed me a detailed work order late on Friday. The total estimate has climbed higher. Does it sound about right? I've never had a car before that has required this much brake work.

    Here is the initial diagnosis. They performed a "vehicle check." They sucked brake fluid from the master cylinder, and the bottom of the master cylinder was full of rust. They pulled the master from the booster and it is leaking from bore. Proportioning valve is also leaking. Rust throughout entire brake system. Rear wheel cylinders leaking, rear shoes coming apart and rear grease seals are leaking onto shoes.

    Labor costs: Vehicle check $88. Remove and replace master cylinder, $88; front brake calipers, $176; rear wheel cylinders, shoes and hardware, $264. Flush brake system, $88. Bleed system, $88. Remove and replace rear grease seals and bearings, $176. Remove and replace proportioning valve, $88. Total labor: $1,056.

    Parts: Master cylinder, $55.78. Calipers, $85.98. Wheel cylinders, $36.96. Shoes, $35.98. Hardware kit $15.39. Brake fluid, $54. Seals, $26.78. Bearings, $140. Proportion valve, $129. Total parts, $579.87.

    Total $1,635.87 plus tax.

    They tell me that the front disc pads are ok, the rubber hoses are still good, and the metal brake lines look ok. I guess the rotors and drums are ok, too. I think they told me they will be resurfacing the drums since they're installing new shoes.

    I'll need to give them a decision on Monday.
     
  15. retropia

    retropia Well-Known Member

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    Regarding the rubber brake hoses, apparently those are getting impossible to find. A friend with a '69 LTD said he'd ordered two sets from different sources, and neither were right. He's having a set custom-made for his car.
     

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