The Caponemobile Posted June 20, 2017 Share Posted June 20, 2017 Once again I need the experience and wisdom of those who have gone before me. A friend, a professional driver of cars, trucks, and probably anything with wheels under it drove "the Caponemobile" last Sunday, after it won a second "favorite in the show" award. My friend, who is also a trained auto mechanic, commented that the car did not roll sufficiently when he released the brakes before the car was completely stopped. In other words, it didn't coast very far. When we got home, we checked the temperature of the brake drums: right front, and left rear were pretty warm; hard to touch. We had driven the car about as far as I have ever driven it; about fifteen miles, and my friend ran it up to about fifty miles an hour. I generally never go faster than forty. Obviously, the shoes are rubbing the drums at those locations. Are the wheel cylinders rusted and stuck? Are the return springs too old and tired to do their job? Are the brakes simply badly adjusted so that the shoes are too close to the drums? There has been no loss of brake fluid, and no evidence of leaking around the brake drums. I have looked at the Chrysler manual, and the adjustment and maintenance of the brakes is clear enough in the text, but at the age of this car, is there some experience others have had that might explain this situation. I should say that I have been driving this car several months without realizing the condition my friend discovered. I thought the brakes were great, and there has never been any pulling left or right as I used the brakes. Before I start tearing things down, I would like to hear others' experiences. Do I have a serious problem, or should I simply back off the brake shoes where they seem to be rubbing, and watch what happens? Finally, in the manual there is reference to the brake pins, but there is no indication of what they are. (This question is irrelevant to the main problem at this point.) Is this simply another term to describe the brake shoe anchor bolts? Any advice, observations, or suggestions on all points will be gratefully received. Thanks to all. Link to comment Share on other sites More sharing options...
keiser31 Posted June 20, 2017 Share Posted June 20, 2017 If my '31 DB was having that problem, I would back the shoes off VERY slightly. If that doesn't work, it is probably the return springs. They are difficult to find with the correct return tension. Link to comment Share on other sites More sharing options...
Carsnz123 Posted June 20, 2017 Share Posted June 20, 2017 When was the last time you changed the brake fluid? A lot of people don't realize that you need to change your brake fluid every 2 years or 48000km. Also check all pivot points for rust. I'll have to dig out my '30 Chrysler manual but a general rule for adjusting brakes is tighten them up until you can't turn the wheel and then let them off so they just clear the drum. Link to comment Share on other sites More sharing options...
Spinneyhill Posted June 20, 2017 Share Posted June 20, 2017 If it were my car I would be looking at the wheel cylinders. With DOT3 or 4 fluid more than a couple of years old and a car that sits for long periods with short drives at others, there will be moisture in it. If you have aluminium pistons in the cylinders, esp. if they are sleeved with stainless steel or brass, the pistons corrode and "seize up" in the cylinder. The spring can't pull the shoes back in. I can take out the pistons and clean them, clean out the cylinder and put it back together without losing much or any brake fluid onto the paint below. Leave the cups in and use a small G-clamp or something to hold the cups in while you are working on it. If you pull the cups over the corrosion products, you may need to replace them if the lip is damaged. After cleaning all cylinders, replace all the fluid. I haven't yet found the master cylinder corroded or clogged with dirt but I have done the cylinders like this a few times between illnesses. You have two cylinders dragging. The other two probably won't be far behind. If the problem occurs on the next drive after adjusting the shoes as suggested by keiser31, you know the problem! The other side of it is, if the shoes were in adjustment, they can't really go out of adjustment in this way, can they? 1 Link to comment Share on other sites More sharing options...
C Carl Posted June 20, 2017 Share Posted June 20, 2017 The erudite Spinney' has , as usual , nailed it. He has combined vast experience and knowledge with irrefutable logic. Hydraulic brakes need love and care. While you are getting yours in perfect shape , flush by repeatedly pumping the entire system through with industrial grade ethyl (or , if you like , methyl if you are working outside) alcohol. Open one bleed valve at a time. Use quite a good amount of it , and then blow the system dry. Deteriorating brakes are best fixed when first noticed. - Carl Link to comment Share on other sites More sharing options...
zeke01 Posted June 20, 2017 Share Posted June 20, 2017 Check the left front and right rear wheel cylinders. If they are frozen the other two will be doing all the work and will be hotter because of it. Zeke Link to comment Share on other sites More sharing options...
c49er Posted June 20, 2017 Share Posted June 20, 2017 You should check out the complete system...or at least someone with good mechanical ability. Probably wheel cylinders and master cylinder need disassembly /cleaning etc. Then porper adjustment of shoes. Link to comment Share on other sites More sharing options...
lozrocks Posted July 7, 2017 Share Posted July 7, 2017 Personally, I'd be going through the brake adjustment procedure. You've already said that the car stops well and doesn't pull. To me that says the hydraulic side of things is working properly. Easy check is to back the brakes off just a little. If they are clear of the drums when you start driving they shoes should be clear when you stop. If they aren't then start looking at hydraulics. Link to comment Share on other sites More sharing options...
Spinneyhill Posted July 7, 2017 Share Posted July 7, 2017 As lozrocks says, the hydraulic system is working. But my contention is that hydraulic force is stronger than return spring force! My post is based on my observation that shoes go out but don't retract fully. 1 Link to comment Share on other sites More sharing options...
ArticiferTom Posted July 7, 2017 Share Posted July 7, 2017 I recall when doing mine something about slow or non-returning being caused also by collapsed inners lining on the brake flex lines . May have been more a problem on system that where left empty and dried out . 1 Link to comment Share on other sites More sharing options...
Spinneyhill Posted July 18, 2017 Share Posted July 18, 2017 On 7/07/2017 at 11:11 PM, ArticiferTom said: I recall when doing mine something about slow or non-returning being caused also by collapsed inners lining on the brake flex lines . May have been more a problem on system that where left empty and dried out . On 20/06/2017 at 1:29 PM, The Caponemobile said: Any advice, observations, or suggestions on all points will be gratefully received. Thanks to all. What Tom says +1. That is the other way fluid cannot return - blocked flexible lines. Mine did that too but I don't recall the light staying on - which doesn't mean it didn't happen! The return spring is not strong enough to push the fluid through. But you have one front and one back brake dragging. It seems low probability both front and back hoses would fail at the same time, but.... Link to comment Share on other sites More sharing options...
The Caponemobile Posted July 19, 2017 Author Share Posted July 19, 2017 Here is an update on the Caponemobile hydraulic brake problem. As I reported originally, the car would not roll when it should because one front and one rear wheel were grabbing, presumably from un-released brake shoes. As the above shows there were numerous possible reasons for this, not the least being that the wheel cylinders were seizing from rust and outdated brake fluid. The other most cited possibility was that the return springs were not sufficiently strong. All the suggestions were reasonable, and any or all could be the cause of the evident problem. To me the obvious first approach was to follow the path of least resistance. I backed off on the adjustment of the two brakes that had been binding (according to the heat evidence), and tested the car. (That meant that the brake pedal goes almost half an inch lower than before the adjustment.) The car passed preliminary tests. Since then I have driven the car nearly 100 miles, incrementally, and found neither a "coasting" problem, nor unusual heat at the brake drums. It would appear the immediate problem is solved. Right now I am trying to gather more history about my car. It was meticulously restored (has won several prizes including one where it was second best in class in a large show), and I need to know when this work was done. The last owner is still alive and I hope to make contact with him. I would like to know how old the last restoration is. If it is very many years it might be a good idea to overhaul the brake system because it is true that dormant cars can decline as much as many in regular use. When I have the answers to my above question I will know whether it is time to do a brake overhaul, or to just enjoy my favorite toy as it is. To me, brakes, and tires are the two most important factors in any car to be driven no matter how little or how much. Thanks again to all who have offered so much good advice, and experience regarding my favorite car ever. 1 Link to comment Share on other sites More sharing options...
Spinneyhill Posted July 19, 2017 Share Posted July 19, 2017 If you do nothing else, at least replace the brake fluid. It will slow any corrosion of the wheel cylinder pistons and take care of any tendency for brake fade. If it were my car, I would inspect and clean the brakes as soon as I could. As you say, they are important and you need to know if they will be reliable, even over this summer. You should be able to do all of the wheel cylinders in a weekend: clean out any corrosion products, reassemble and bleed = replace the fluid. Link to comment Share on other sites More sharing options...
C Carl Posted July 20, 2017 Share Posted July 20, 2017 Flush with industrial grade ethyl or methyl alcohol, opening one bleed valve at a time. Then blow compressed air through each line. This will clean and dehumidify the system. - Carl Link to comment Share on other sites More sharing options...
1939_Buick Posted July 20, 2017 Share Posted July 20, 2017 2 hours ago, C Carl said: Flush with industrial grade ethyl or methyl alcohol, opening one bleed valve at a time. Then blow compressed air through each line. This will clean and dehumidify the system. No it will not. Unless you have an extremely good (super expensive) ultra dry compressed air system the air will have a lot of moisture. Air filters do not remove much moisture. Home type air compressors will do the opposite of dehumidify. Nitrogen can dehumidify. Link to comment Share on other sites More sharing options...
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