mach0415 Posted January 31, 2009 Report Share Posted January 31, 2009 Its time to glean info from higher powers than me. I have replaced my entire brake system on the '47 P15. I had my shoes relined, all new hydraulics and lines, hoses, etc. All brakes adjust and fit perfectly. However, the right front brake is very tight, even at the lowest adjustment. This is why I elected to replace all the VERY old brake linings in the first place. My assumption was that the linings were swelled and I found they were all concave, due to separation from the webbing. Now that I have all new linings, the right front is doing the same thing as before. If I tighten the drum to specs, I cannot turn the wheel assembly. I tried to interchange the drums from the right to the left, thinking the diameter was off, but the result is the same (what was the definition of insanity???) Is it possible that the backing plate is warped, causing a "canted" brake shoe-to-drum contact? Losing my hair:confused: Mark Quote Link to comment Share on other sites More sharing options...
JIPJOBXX Posted January 31, 2009 Report Share Posted January 31, 2009 Mark I made a mistake when putting my brakes together and it did the same thing. I had not put in the flat washers that separate the brake shoes from the backing plate. It took me the longest time to figure this out and when I did all I did was install those washer shims in the right position. I know how you feel as its exasperating to have problems with brakes and not know where to turn. Jon Quote Link to comment Share on other sites More sharing options...
blueskies Posted January 31, 2009 Report Share Posted January 31, 2009 One thing to check is the length of the little push rods that go between the shoes and the wheel cylinders. I had a couple in my kit that were the wrong length and used my old ones to fix the issue. Also, did you do a major and minor adjustment of the shoes? Are you using a brake tool like the Ammco or similar? If not, I would suggest you find one or make one. Do a search of this forum and you will find lots of threads about the brake tool. It's my opinion that you can't get the brakes adjusted correctly without the tool. Pete Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted January 31, 2009 Report Share Posted January 31, 2009 Wheel cylinder style-2 piece piston or one piece piston causes the need to check out the push rod length. You will not be able to get the drum on as already said with too long of pushrod. And now with chinese and India made brake parts being made for our old MoPars will we need a third length push rod? Bob Quote Link to comment Share on other sites More sharing options...
RobertKB Posted January 31, 2009 Report Share Posted January 31, 2009 If everything is as it should be and you still have the problem, take those shoes back to where you got them or any brake shop and have them shave of a few thousand. I had that problem and that was the solution. Quote Link to comment Share on other sites More sharing options...
Lou Earle Posted February 1, 2009 Report Share Posted February 1, 2009 I was having similar trouble on one front drum. Then I went and re read the major brake adjustment in the manual- BE SURE BEFORE YOU START ADJUSTING THEAT THE BOLT-ADJUSTER THAT HOLDS THE SHOE ON- THAT THE ARROW POINTS AWAY FROM THE SHOE IT ATTACHÉS-THEN SA RT THE ADJUSTING. I re did the shoes starting with arrow pointing away - adjusted the brakes using the amco tool got them right then turned the Minor adjuster all the way down then the drum slipped right on. Then adjusted minor adjuster to just scrubbing backed of a hair and all seEms fine Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted February 1, 2009 Report Share Posted February 1, 2009 One thing to check is the length of the little push rods that go between the shoes and the wheel cylinders. I had a couple in my kit that were the wrong length and used my old ones to fix the issue.Also, did you do a major and minor adjustment of the shoes? Are you using a brake tool like the Ammco or similar? If not, I would suggest you find one or make one. Do a search of this forum and you will find lots of threads about the brake tool. It's my opinion that you can't get the brakes adjusted correctly without the tool. Pete Some pictures of the different piston/pushrod styles. Mismatching a long pushrod with a tall piston can cause a drum not to be able to be installed over the shoes no matter how much time you spend adjusting the anchor pins. Bob Quote Link to comment Share on other sites More sharing options...
RobertKB Posted February 1, 2009 Report Share Posted February 1, 2009 Those are great pictures. Thanks for posting. It goes to show that you should never throw anything out as Murphy's Law states you will need it again if you do. Quote Link to comment Share on other sites More sharing options...
Normspeed Posted February 1, 2009 Report Share Posted February 1, 2009 Yeah thanks Bob. I saved those to my Mopar Brakes folder. Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted February 1, 2009 Report Share Posted February 1, 2009 I am more than happy to help out guys!! Bob Quote Link to comment Share on other sites More sharing options...
mach0415 Posted February 1, 2009 Author Report Share Posted February 1, 2009 This is great info...Thanks. come to think of it, I did not have these problems until I replaced the front wheel cylinders on the right side. And it seems that one was a different color - black paint vs the regular cast iron. I will check this tomorrow. More than likely it is a push rod length issue. You guys are great! As I go, I help to spread the answers to the mistakes I have made to others who are less wise, like me now. That's what we're all about, right? Quote Link to comment Share on other sites More sharing options...
Tim Frank Posted February 2, 2009 Report Share Posted February 2, 2009 Those are great pictures. Thanks for posting. It goes to show that you should never throw anything out as Murphy's Law states you will need it again if you do. One of the corollaries to Murphy's Laws is that "Murphy was actually an optimist...." Quote Link to comment Share on other sites More sharing options...
mach0415 Posted February 3, 2009 Author Report Share Posted February 3, 2009 I checked out the rod length, but it was correct. HOWEVER, the wheel cylinder that was painted black (all others were plain cast finish) has a longer piston and bore. Since I had 6 extra pins, I went ahead and machined it shorter to accomodate the difference:cool: . Looks like 'ole Murphy was thwarted again...until next time. Oh yeah, are there supposed to be washers between the front shoes and the backing plate? The rear did, but the front did not. Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted February 3, 2009 Report Share Posted February 3, 2009 Stories like this make me glad I converted to disc brakes. Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted February 4, 2009 Report Share Posted February 4, 2009 These old plymouth (MoPar) brakes are some of the best brakes produced in their day. They will stop the car safely and easily. With these Lockheed style brakes have patience for them to wear in to the drums /keep em adjusted up and you will be rewarded with great working brakes. I used to drive a 1953 OD Plym wagon that had super-duty 12 leaf rear springs with 700X15 rear tires all for hauling tons of heavy car parts tools ect. Parted out a 1948 NewYorker-loaded the straight 8/trans/rear axle/rad/seat/ engine hoist/ me/lotsa tools and a 250lb passenger. Way over loaded! The original 10" brakes never failed to safely stop that car in any situation over 10 years of every day driving. Did 4 or 5 relines too! I like em stock and proper! The factory brakes work great if you learn the tricks to fixin them. This site will help anyone wanting to do them right. Bob Quote Link to comment Share on other sites More sharing options...
Normspeed Posted February 4, 2009 Report Share Posted February 4, 2009 I agree, Bob. They can be finicky to set up but once there, they are as good as drum brakes can get. I've got the stockers on the front of my 53 wagon and I upgraded the rears to stock Dodge 11" brakes, an easy bolt in. Drum brakes do have their own personalities, like they will get hot and fade in extreme long downhill grades if you keep riding them, and if you drive through a very deep stretch of flooded street they will develop a high pedal and won't stop as well. To me, it's part of what I learned about driving old mopars way back in the day. The disc conversions are a nice upgrade but I think that for many of us and the kind of driving we do, not really a necessity. PS, Mr. Undercoatney probably really needs the disks. From what I hear, he drives like his head was on fire and his ass was catchin'. (Charlie Daniels) Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted February 4, 2009 Report Share Posted February 4, 2009 I will not dispute the point that when correctly setup the Mopar drum brakes are as good as drum brakes can get. However, if you have a wheel cylinder failure 1,000 miles from home and your Ammco tool and brake bleeder are sitting in your garage at home what are you going to do? With my disc setup I can walk in any bubble pack parts store with a high school dropout behind the counter and buy the repair parts I need. And my disc conversion cost about the same (or less) than all the stock parts required for a complete rebuild. And the stopping power is better for my driving style. Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted February 5, 2009 Report Share Posted February 5, 2009 You don't need the Ammco tool and a bleeder to fix brakes on these old MoPars. They are great to have-but not a must! If you were to lose a W/Cyl-Pull the drum/replace the wheel cylinder-keep the anchor arrow pointing to where it was. Jam a stick against the brake pedal and seat-open bleeder .Repeat 4-5 times. Brakes are bled get home-have a beer/pop what ever! Quit sweating the scary MoPar brake stories. Wear em in-keep em adjusted-save Ebay money-get along with out all the special tools. Enjoy your car. Bob Quote Link to comment Share on other sites More sharing options...
homer2105 Posted March 2, 2012 Report Share Posted March 2, 2012 I've been on this COMPLETE brake on my 48 D24. I have bought brand new slaves, sent shoes out to be relined, had drums turned, replaced all hard lines and hoses, rebuilt master put all this back together . When I installed shoes I made a tool to check to see if they were equally centered. Had a bear of a time bleeding (didn't know about the bench bleed) finally got a halfway decent pedal and was mashing on it to see if it was going to hold when all of a sudden the pedal went to the floor. There was a puddle of fluid under right front. Upon inspection I noticed that the seal came out from arond the piston. I remember when I put thes together I had 3 different lenghths of those push rods that go betewwen cyl pisyon an shoe. It appears the rod was too short and allowed the piston to come past the end of the bore. Which length rod should I be using? These slaves are brand new from Roberts. When I was taking all this apart I disn't realize the differnet lenghts. What now, oh Gods of Mopar brake systems? Quote Link to comment Share on other sites More sharing options...
Jerry Roberts Posted March 2, 2012 Report Share Posted March 2, 2012 Use the longest rod that you can , and still be able to get the drum back on . Quote Link to comment Share on other sites More sharing options...
40P10touring sedan Posted March 2, 2012 Report Share Posted March 2, 2012 I had issues with an old mopar of mine...my dakota would lock the R/R oem brakes every time it rained or the humidity was up. I'd hit the brakes 1st and 2nd time and that R/R would lock up solid - 3rd time it went away. Finally found the problem and it was two fold- A) the R/R drum{the culprit} was a little smaller than the left...guess the shop thought it was close enough but .020 was enough to be an issue I guess, B} the oem replacement shoes were cheapos and swelled with high humidity, once I went and got my own of a better brand the problem went away. Just goes to show you that sometimes you should trust yourself and not others work. Quote Link to comment Share on other sites More sharing options...
ptwothree Posted March 3, 2012 Report Share Posted March 3, 2012 I lost a pin/pushrod, whatever you want to call it, while redoing mine. Went to the local napa store. They had a part very similar to what I needed. Just too long. I ground down the piston end of the rod using one of the others as a template....Worked great. Quote Link to comment Share on other sites More sharing options...
40P10touring sedan Posted March 3, 2012 Report Share Posted March 3, 2012 I will not dispute the point that when correctly setup the Mopar drum brakes are as good as drum brakes can get.However, if you have a wheel cylinder failure 1,000 miles from home and your Ammco tool and brake bleeder are sitting in your garage at home what are you going to do? With my disc setup I can walk in any bubble pack parts store with a high school dropout behind the counter and buy the repair parts I need. And my disc conversion cost about the same (or less) than all the stock parts required for a complete rebuild. And the stopping power is better for my driving style. Just for clarity sake, are those tophats/hubs or whole one piece hub/rotor assemblies? Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted March 3, 2012 Report Share Posted March 3, 2012 Just for clarity sake, are those tophats/hubs or whole one piece hub/rotor assemblies? I bought the PLYDO kit several years back. Everything pictured are the parts I used. If I recall it was about $500.00 for everything. Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted March 3, 2012 Report Share Posted March 3, 2012 Seems more and more chinese hydraulics are being installed in these lockheed Mopar systems. A good reason for brake issues. Use only USA parts if at all possible. They last and work better! Quote Link to comment Share on other sites More sharing options...
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