Brooklyn Beer Posted May 1, 2020 Share Posted May 1, 2020 This one has me stumped. Last month I installed a new dual master cylinder to replace the single. At the time I did new wheel cylinders, spring kits, shoes etc. Bleed the system clean with new fluid front to back. Adjusted brakes as I always have. No binding or grabbing. Free rolls in the driveway in neutral. Here is where the problem starts and I have had the drums off (cut clean) more times then I care to mention, changed brand and size of shoes twice and no matter what after a 4-5 mile ride the back brakes approach pretty hot at just 45 mph easy driving. The only I can think of at this point is that I crossed the new lines from the new dual master into the new distributor block and have the rears working off the front reservoir. Anyone? Link to comment Share on other sites More sharing options...
61polara Posted May 1, 2020 Share Posted May 1, 2020 Replace the rubber brake hose over the rear axle. It has swollen internally. The MC has enough pressure to force the fluid to the brakes, but the brake return springs don't have enough strength to return the fluid. The pressure builds up in the rear brakes and they won't release. Here is a picture of what a swollen brake hose looks like. Outside looks fine, but cut it open and you can see what is going on. The end of the hose is totally out of focus but you can see how small the center opening is. 1 1 Link to comment Share on other sites More sharing options...
Brooklyn Beer Posted May 1, 2020 Author Share Posted May 1, 2020 (edited) Holy crap. Would have never guessed. Thanks ! I have missed driving mine to work as it is my semi daily in the rotation. Edited May 1, 2020 by Brooklyn Beer (see edit history) Link to comment Share on other sites More sharing options...
frededwarrds Posted May 2, 2020 Share Posted May 2, 2020 61polara, Bang On. I discovered this on my car. It had inboard rear disc brakes which nearly set the car on fire. I changed everything discs , calipers and pads and luckily I tried to purge the brake lines with metholated spirits and compressed air and found a blockage. Alas, the brake hoses were as you state. RS. They looked good on the outside. I changed the 2 front ones as well. The left side one was restricted also. From then on I replace everything important on my cars made from rubber that is at least ten years of age. Personally , and only personally, l wouldn’t bother fitting a dual brake system on old cars. I know of no one whose brakes have failed except for ones that have not been serviced and flushed. Should be every year, but just flush them sometime per decade!! Link to comment Share on other sites More sharing options...
Frank DuVal Posted May 2, 2020 Share Posted May 2, 2020 On 4/30/2020 at 8:08 PM, Brooklyn Beer said: I have had the drums off (cut clean) more times then I care to mention, Yes, since every time you do this you take years of wear off a drum! Unless the drum is visibly ridged/warped/belmouth, etc, no need to turn them. Always replace 50 year old rubber hoses. They are just check valves now! And Fred, around here steel lines rust out starting at about 10 years of daily driving. They rust from the outside, no flushing* will help that. Great feeling going through red lights with traffic flowing.... Usually rusting behind a clamp where it is not visible. And that's another thing. Both time it happened to me, the dual system did not keep me from going through the intersection, so why bother adding it to an older car? Just inspect the lines. CAREFULLY! Or, replace them all with Cunifer, which is what I do now, I tired of replacing steel lines twice! Salt never sleeps, as I misquote Neil Young. *Of course washing the undercarriage might help, but who does that in the winter? Only a few serious people. 1 Link to comment Share on other sites More sharing options...
frededwarrds Posted May 2, 2020 Share Posted May 2, 2020 I’m hoping Brooklyn Beer has solved his problem. On a lighter note . Down under where we live we don’t have salt on the roads, thank goodness, but outback there are a lot of limestone roads which can play havoc. Fortunately not enough things to hit should your brakes fail. I’ll have to look up ‘cunifer’ . I thought it was a pine tree! . So if you don’t want to hit a conifer pine you should fit a cunifer line ? One thing that intrigued me was the fitting of copper brake lines to cars in the USA. Here it is definitely not legal. They believe it won’t hold pressure under stress. The flare nut isn’t designed for soft copper. Also it is prone to work harden with vibration and will crack. If you have salt on the roads it would be cure for corrosion. That aside, I know of cars and trailers with copper lines and never heard of any failure. Interesting. Link to comment Share on other sites More sharing options...
Brooklyn Beer Posted May 2, 2020 Author Share Posted May 2, 2020 Just waiting on a hose. Seems brake issues are going around here. Also waiting on the rebuild kit for the 50 Chrysler master. Link to comment Share on other sites More sharing options...
JACK M Posted May 2, 2020 Share Posted May 2, 2020 7 hours ago, Brooklyn Beer said: Just waiting on a hose. Seems brake issues are going around here. Also waiting on the rebuild kit for the 50 Chrysler master. Ahh the joys of maintaining a collection. "It just goes to show you, Its always something" 1 1 Link to comment Share on other sites More sharing options...
Brooklyn Beer Posted May 2, 2020 Author Share Posted May 2, 2020 I am going to get the new brake lines in an hour. I am a preferred customer at O'Reilys for some reason and they got them in record time. Already removed the back and it looked bad. Don't know if the undercoating was applied in 1963 or not but if so I would bet to say the line was original to the car with the amount of it on the end and clips. Some of the older brass nuts on 30's cars are prone to cracking. It caused a catastrophic event at one of the Franklin treks some years back. . Link to comment Share on other sites More sharing options...
Brooklyn Beer Posted May 3, 2020 Author Share Posted May 3, 2020 OK, changed out all three brake lines and I think the back was original by the over spray undercoating on it. One of the fronts had been changed but the other side matched the rear. Only had one hose bracket clip shoot off into the nether region of the garage which is right next to the black hole for sockets. It is never to be seen again of course even after sweeping the garage out. So I have pick up a new clip. Spent the next hour bleeding brakes. OK, test run. I would call it a victory. Nowhere near as warm as yesterday. Black and white difference. Still need to do a final adjustment and one more bleed as I think the passenger rear has a wee air in it. One thing I instantly noticed is how much more "free" the car felt going down the road. Must have been dragging some since I got it as the difference was easy to feel right away and that big old 361 felt like a dog off a chain wanting to run. Love this club. I have never come here with a problem that the collective membership could not fix. 3 1 Link to comment Share on other sites More sharing options...
frededwarrds Posted May 3, 2020 Share Posted May 3, 2020 Hi Brooklyn Beer, I’m happy that you found success. One thing I do after I bleed the brakes initially , is I bleed them again after about a week or so of driving. No matter how much brake fluid you push through the fluid seems to retain micro bubbles. That air in the system I find is pesky and will work it’s way to the cylinders or back to the MC in time. All the best. 2 Link to comment Share on other sites More sharing options...
Frank DuVal Posted May 4, 2020 Share Posted May 4, 2020 On 5/2/2020 at 2:39 AM, frededwarrds said: One thing that intrigued me was the fitting of copper brake lines to cars in the USA. Here it is definitely not legal. Not legal here either! Now, I do think there were some manufactured with copper (20's) before they were determined to crack and fail. Copper work hardens and cracks, not something you want with your hydraulic brake system! Compression fittings not legal in this state, but one does see them from time to time as jack-legs replace a section of rusted out line. OK to get home, but a proper repair should be made later. I know, A Swedgelock (brand) stainless steel fitting should last forever, same with a regular brass compression fitting, but it is easy to install them wrong, and there goes the fluid..... If everyone had installed compression fittings correctly, they would not have made to no no list on our state safety inspection. Then there are those that repair rusty lines with tape, epoxy......😧 Link to comment Share on other sites More sharing options...
Brooklyn Beer Posted May 4, 2020 Author Share Posted May 4, 2020 Well victory was short lived. 20 miles from the house they began dragging again. Both sides. I think I can try two different routes next. Swap the lines at the splitter block and see if the fronts start getting hot or disconnect at the rear flex connection and blow the line out from the new master connection out towards the rear. What say you ? Link to comment Share on other sites More sharing options...
Brooklyn Beer Posted May 4, 2020 Author Share Posted May 4, 2020 Now I after some thinking about how I drove the car yesterday and how I drove the car this morning one thing comes to mind that I did this morning that I did not do yesterday. Leaving for work I had to back out about 100 yards to turn around to leave the property. Yesterday when driving I did not do any backing up but just drove straight forward the entire time. Looking at page 5-5 and 5-6 of the manual the pictures show the adjuster and am assuming being one picture has the star wheel on the left and one of the right that is just relative to what side of the car your working on. Stupid question. What would happen if you have the adjuster and cable flipped around? The car is still at work tonight as I will be throwing it on my trailer tomorrow but this possibility has me thinking. Thoughts? Would not be the first time I was a bonehead. Link to comment Share on other sites More sharing options...
TerryB Posted May 5, 2020 Share Posted May 5, 2020 Self adjusting brakes self adjust when backing up, at least that’s what is supposed to happen. Maybe yours are not set up correctly https://www.knowyourparts.com/technical-resources/brakes-and-brake-components/importance-drum-brake-self-adjusters/ 1 Link to comment Share on other sites More sharing options...
Brooklyn Beer Posted May 5, 2020 Author Share Posted May 5, 2020 I honestly can not see how I could have gotten it backwards being I only take apart one side at a time. Will check. But blowing out the line from the front distribution block to the rear hose connection seems more of what I need to do. Through this entire process of tracing the issue I have never had to back off the adjuster to get the drum off. When it sits the pressure in the line slowly bleeds back to the master. Being that both hubs are sticking it is either in the front of the rear distribution block or the line from the new front block. Is there anything I should use to flush the brake line after blowing out the fluid? Link to comment Share on other sites More sharing options...
Frank DuVal Posted May 5, 2020 Share Posted May 5, 2020 On 4/30/2020 at 8:08 PM, Brooklyn Beer said: Last month I installed a new dual master cylinder to replace the single Did you adjust the pedal push rod into the master so that the master piston returns completely to the stop position? If the piston does not return all the way, pressure in the system will not relieve and the brakes will lock up. DAHIK....... ok, left the spacer out of my aunt's 65 Chevelle where it mounts to the firewall (manual brakes). Didn't take long before it wouldn't move. She did out wait it and drive it back home, where I said, hmm, now that's what that piece of metal is sitting in the garage....😉 Hey, I was just a kid back then. But a life lesson learned, which has come in handy with others doing master cylinder changes/swaps/rebuilds and having the brakes lock up. 1 Link to comment Share on other sites More sharing options...
Brooklyn Beer Posted May 5, 2020 Author Share Posted May 5, 2020 No I did adjust that rod and I am not seeing anything in the manual. I can not find anything about that. I will have to crawl under the dash and see. But if this was the case would it not be both the front and rears? Link to comment Share on other sites More sharing options...
JACK M Posted May 5, 2020 Share Posted May 5, 2020 Easy to determine if its a hydraulic problem, vs mechanical problem (adjusters). Crack a bleeder, if the brakes release its not the adjusters. If they don't release its something mechanical. 2 Link to comment Share on other sites More sharing options...
PFitz Posted May 5, 2020 Share Posted May 5, 2020 (edited) Chris, Look for mention of "pedal free play". That's the amount the foot pedal should move before you feel resistance of the master piston moving. The reason for it is so that the piston cup retracts enough to uncover the compensating port. There are two ports in a master cylinder for each the piston cup. One larger one is behind each the piston cup that feeds fluid from the reservoir into the master cylinder bore to keep it filled with fluid. The other is very small hole just on the pressure side of the piston cup lip - it's only about .20 to .25 inch - and often missed because they tend to plug up with rust. It allows fluid to bleed back into the reservoir as the fluid changes volume with changes in temperature. With that compensating hole plug, or covered by the piston cup not retracting far enough in the bore, as the brake fluid heats up it expands and applies the brakes. And when you release the pedal quickly the suction created pulls some fluid past the cup lip from the big hole to the pressure side of the cup. That's why you can "pump up the brakes" by quick pedal movement. So then, with the quick release of the pedal,not all the fluid gets sucked back by the piston cup to return to the reservoir and the shoes can't retract as much as they should. That's where the compensating port comes in again to bleed off that remaining pressure and let the shows retract back to the adjuster stops. FYI, Swollen brake hoses will do the same after releasing the pedal. And old brake hoses never swell outward - always inward where you can't see it. Paul Edited May 5, 2020 by PFitz (see edit history) 1 Link to comment Share on other sites More sharing options...
frededwarrds Posted May 6, 2020 Share Posted May 6, 2020 Hi Brooklyn Beer, sorry to see you are still having grief with this. Following on Jack M and PFitz comments and if the master cylinder piston is fully returning I would be looking to see if that tiny hole is blocked. Also, On a car with front discs the pressure can build up. I had this exact problem. You would drive the car for about 10 miles and the discs would lock up even without applying the brakes. The calipers pulse against the discs. There is a valve in the front of the MC piston on drum brake cars which causes this and must be removed when converting to discs. As you have drums all around this shouldn’t be a problem. Maybe Swap the pipes around as you suggested? There is a thread somewhere here recently explaining this....... Sometimes on a job I have to go back to the start of my problem. I take for granted that a new part I fit has nothing wrong with it so I keep presuming the problem is somewhere else. And , after all these years, I still fall for it!!! Maybe look into the MC a little more. I hope you find your answer soon. 1 Link to comment Share on other sites More sharing options...
Brooklyn Beer Posted May 15, 2020 Author Share Posted May 15, 2020 OK, after rebuilding the 1950 Windsor master twice (second time with new old stock parts because new sucked) I got around to swapping the lines at the splitter block for the front and rear off the master and the backs started getting hot still after a 3 mile stop and go drive around the neighborhood. So I will make a new line from the block to the rears this weekend and see if that helps. If not i am going back to the single punch bowl master ! 1 Link to comment Share on other sites More sharing options...
PFitz Posted May 15, 2020 Share Posted May 15, 2020 12 hours ago, Brooklyn Beer said: OK, after rebuilding the 1950 Windsor master twice (second time with new old stock parts because new sucked) I got around to swapping the lines at the splitter block for the front and rear off the master and the backs started getting hot still after a 3 mile stop and go drive around the neighborhood. So I will make a new line from the block to the rears this weekend and see if that helps. If not i am going back to the single punch bowl master ! Chris, Did you check to see if the compensating port for the master rear piston is clear ? Or, when the foot pedal is not being pressed, if the rear piston cup is not pulling back far enough to uncover that port ? Sometimes the wrong lip length cup gets used and even with the piston all they way back against the stop the compensating port is still covered and brake fluid in the lines and wheel cylinders can't get back to the reservoir with your foot off the pedal. Then as you drive a few miles and the underside of the car heats up, the brake fluid expands, moves the wheel cylinder pistons outward and makes the shoes drag. Paul 2 Link to comment Share on other sites More sharing options...
Guest Posted May 15, 2020 Share Posted May 15, 2020 I read all the posts about brakes and certainly wish Brooklyn Beer all the best. These posts really make me happy to have my "Mechanically Actuated" brakes. Link to comment Share on other sites More sharing options...
54vicky Posted May 15, 2020 Share Posted May 15, 2020 it is either a problem with the" NEW "master or the rod length not allowing the return of fluid to master as you have pretty well eliminated any other possible problem.remember new does not mean it is perfect.they coin them defective Link to comment Share on other sites More sharing options...
wmsue Posted May 15, 2020 Share Posted May 15, 2020 Do you need - or do you have a proportioning valve? Just wondering because I installed one when I switched from single to dual MC Good Luck Bill Link to comment Share on other sites More sharing options...
Brooklyn Beer Posted May 15, 2020 Author Share Posted May 15, 2020 Paul the master on the 50 is working as it should. I get the blurble back in the master when I return the pedal through the port. Brakes releasing find. The NOS kit allowed the rod to seat at the depth within the piston as the old one. The new kit would not even allow the rod to even get more then 1/4 of the way in the new piston as the compared to the old one. On the 63 I swapped the lines going into the junction block so what was controlling the fronts is now controlling the rear and the rears still heated up. I have swapped out the single to a dual master. Changed the flex lines. Rear brake cylinders, adjusted more then once. So am going to bend up a new line going to the rear and see what that does. If the rod was not allowing the fluid to fully return would flipping the lines not cause the other set of brakes to start hanging up ? Link to comment Share on other sites More sharing options...
PFitz Posted May 15, 2020 Share Posted May 15, 2020 (edited) Chris, Yes, swapping the lines at the master and still having the rear brakes dragging rules out the master being the cause. So, if it's both rear brakes dragging the problem is most likely somewhere between the tee to the rear, and the split at the rear axle. Unless there is a problem with both lines, and/or, inside both drums of the rear axle. Paul Edited May 15, 2020 by PFitz (see edit history) Link to comment Share on other sites More sharing options...
pont35cpe Posted May 15, 2020 Share Posted May 15, 2020 Sounds a lot like a problem i once had decades ago, the feed line to the rear was rusted inside, master could push fluid thru but the rust would not let the fluid flo in reverse. 1 Link to comment Share on other sites More sharing options...
Brooklyn Beer Posted May 25, 2020 Author Share Posted May 25, 2020 On 5/15/2020 at 6:40 PM, pont35cpe said: Sounds a lot like a problem i once had decades ago, the feed line to the rear was rusted inside, master could push fluid thru but the rust would not let the fluid flo in reverse. Exactly what i just found today. Disconnected the splitter at the rear and sucked back through each bleeder. Good flow in reverse. Took brass T off and cleaned it out. Not stopped up. Went up front and disconnected the line feeding the rear. Went to the back and stuck the flex line in a pop bottle filled with fluid and went back up front and proceeded to start vac pumping. It held 15 pounds coming back to the master for 10 minutes before slowly starting to suck back. So ripped out the old line and replacing. Question. Being I now have a dual master can I run 3/16 to the back (Because I have a coffee can full of the correct nuts) or should it be 1/4 inch (which i don't have a can full of fittings for) 1 Link to comment Share on other sites More sharing options...
pont35cpe Posted May 25, 2020 Share Posted May 25, 2020 24 minutes ago, Brooklyn Beer said: Exactly what i just found today. Disconnected the splitter at the rear and sucked back through each bleeder. Good flow in reverse. Took brass T off and cleaned it out. Not stopped up. Went up front and disconnected the line feeding the rear. Went to the back and stuck the flex line in a pop bottle filled with fluid and went back up front and proceeded to start vac pumping. It held 15 pounds coming back to the master for 10 minutes before slowly starting to suck back. So ripped out the old line and replacing. Question. Being I now have a dual master can I run 3/16 to the back (Because I have a coffee can full of the correct nuts) or should it be 1/4 inch (which i don't have a can full of fittings for) Great, glad to hear you found the problem. That`s one of those things that`ll drive you nuts trying to figure out the problem. Sorry but i can`t answer your question on using the smaller line. Maybe someone else will chime in with an answer. Tom 1 Link to comment Share on other sites More sharing options...
Frank DuVal Posted May 25, 2020 Share Posted May 25, 2020 Did the rear line originally just feed two brakes, and it was 1/4"? If so, then nothing changed, so 1/4" it is. Now if originally somehow the rear 1/4" feed line also fed another brake, and now it doesn't, then that is a different situation, and maybe a smaller line is OK. BTW, vacuum pumping and 15 psi does not compute. You mean 15" of Mercury vacuum? Or do you mean you had a good vacuum, about perfect, aka, 14.7 psi difference (atmospheric pressure of the day) between the outside air and the vacuum of your system? If using an absolute pressure gauge, it would be 0 psi. aka manifold pressure (instead of manifold vacuum) on an internal combustion engine. More confused?🙃 1 Link to comment Share on other sites More sharing options...
PFitz Posted May 25, 2020 Share Posted May 25, 2020 Agreed with Frank. The engineers used 1/4 inch for a reason. A smaller line will not flow volume as fast and fluid return will take longer at the same shoe return spring tension. Not a big deal, but the shoes will delay on/off just a bit longer to feed the original size wheel cylinders, which have not changed size. Might put them a bit out of balance with the fronts, and that might affect wet road braking ???? Be safe and stick with what the engineers used. It worked when new. Paul 1 Link to comment Share on other sites More sharing options...
Brooklyn Beer Posted May 25, 2020 Author Share Posted May 25, 2020 Going back with 1/4 and gives me a good reason to buy a roll of 1/4 Nickle copper and not attempt to bend and flare the old steel stuff I have here. And yes, I misstated, With my vacuum bleeder I was pulling and holding 15-18 in.-HG Mercury for about 5 -10 minutes. Of course nobody in town has copper nickle brake line and I will be following your advice Paul on what you explained in another thread of running brake lines and annealing. 1 Link to comment Share on other sites More sharing options...
Brooklyn Beer Posted May 26, 2020 Author Share Posted May 26, 2020 (edited) Well the parts house was nice to call after I left and said they found a roll of zinc steel line so being I figure it will surely outlive me I went and got it. I could barely unroll the old stuff I had here. The old line came out in 2 pieces so of course the new line went in the same way and I was able to use all the old clamps. The 20 dollar double flare tool gave all it had to make the correct ends in that "soft" steel line but in the end no leaks at all 4 connections. Bleed the brakes and went for a quick 3 mile ride before the rain came back and all felt nice and cool. Tomorrow will get into town and hit every stop sign and light I can find and see if things stay cool. Love how those early 60's Mopars ride. Edited May 26, 2020 by Brooklyn Beer (see edit history) Link to comment Share on other sites More sharing options...
Frank DuVal Posted May 26, 2020 Share Posted May 26, 2020 Good work! I buy the SUR&R brand Cunifer. Summit Racing has it at a good price. Summit also has stainless steel flare nuts, and the very hard to find stainless steel brake line armor (aka guard). That is the spring looking stuff wrapped around some manufacturer's brake lines where gravel might hit the line and bend it. I do not know why anyone would anneal brake line. Just do a proper (and legal!) double flare (inverted flare) and call it a day, knowing you made it just like the OEM did. 1 Link to comment Share on other sites More sharing options...
Brooklyn Beer Posted May 26, 2020 Author Share Posted May 26, 2020 The entire run to the back was that factory "spring" type covered line and it was very soft even after 60 years. Defiantly not stainless. I figure this harder steel line should last at least that long with limited driving now. On danger spots I slid over some rubber vac line I had laying around. Link to comment Share on other sites More sharing options...
PFitz Posted May 26, 2020 Share Posted May 26, 2020 (edited) 7 hours ago, Frank DuVal said: Good work! I buy the SUR&R brand Cunifer. Summit Racing has it at a good price. Summit also has stainless steel flare nuts, and the very hard to find stainless steel brake line armor (aka guard). That is the spring looking stuff wrapped around some manufacturer's brake lines where gravel might hit the line and bend it. I do not know why anyone would anneal brake line. Just do a proper (and legal!) double flare (inverted flare) and call it a day, knowing you made it just like the OEM did. On the earlier copper brake line fittings - the type with the long tapered flair nuts - there is not enough length of thread engagement to safely fit a double flair. The single flair with the Kunifer-10 is less likely to leak without need of over tightening the flair nut if the flair is annealed and softened back to original. And yes, the K-10 can develop radial splits at the flair if not annealed. That's why I started doing it many years ago on all my customer's brake line replacement work. That's what Chris is talking about that I told him about for his Franklin. Those are the type fittings on his Franklin, and they can't safely use a modern double flair. The kit to replace the original copper lines and brass flair nuts with new, made in the USA, SAE spec long-taper brass nuts, identical to the originals, are available through the Franklin Club. All the money from the Club's Parts Project, such as that kit, goes to fund the making of more replacement parts through the Club. BTW, whenever I do a steel tube flair on more modern cars, I don't anneal them. Paul Edited May 26, 2020 by PFitz (see edit history) 1 1 Link to comment Share on other sites More sharing options...
Frank DuVal Posted May 26, 2020 Share Posted May 26, 2020 Thanks, makes sense now!👍 Copper does need annealing. 7 hours ago, Brooklyn Beer said: I figure this harder steel line Harder? I'm sure it is the same stuff as original, had to meet DOT standards of the day. Unless you bought stainless steel line, that stuff IS hard. Yes, the factory brake armor spring was never stainless (AFAIK) as that cost too much for a disposable car.😉 Link to comment Share on other sites More sharing options...
Brooklyn Beer Posted May 26, 2020 Author Share Posted May 26, 2020 Well went for a 15 mile stop and go drive and things started getting warm again. Not hot but not as cool as the front brakes either. At this point I am about to go back to the single punch bowl master. The only place not checked out was the new distribution tee at the front Link to comment Share on other sites More sharing options...
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