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Brake System Master Cylinder Add On?


Happy 46R

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My 46 Dodge D25C mysteriously developed a brake pull, right front, the other day after a 100 mile trip with the car club. It was mysterious as well because I have driven just over 2,000 miles since buying the car without any brake issues on a stock system and have not made any alterations or adjustments during that time. Despite a complete minor adjustment of all four wheels the pull is still there and a physical inspection of front and rear brakes shows no leaks or obvious wheel cylinder problems. Using the forum I am now isolating on the master cylinder as my first examination, then the rubber connection lines and then wheel cylinders. I have however a concern as I did note some wetness around the master cylinder and it looks like an "after market" or "home built" reservoir was attached to the MC. The first picture is the small reservoir on the firewall that has an internal probe attached to the top cap to show fluid level and plain copper tubing leading to the MC. The second photo is not properly aligned as the MC that is on the left should be at the bottom of the photo but you can still see the copper tubing coming into the brass fitting that is threaded into the MC filler cap. Is anyone familiar with this device or have any information on how it may affect the braking system if at all? Thanks

Master Cylinder Extension.jpg

Master Cylinder Connection.jpg

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Hi Sniper and thanks for the reply. Yes I did a minor adjustment to all four wheels after I noticed the pull. What caught me off guard was that the pull happened in two braking applications. I was travelling at highway speeds and had used the brakes a couple of times at intersections or lane changes without any problems. As I pulled into our small town I noticed a small tug when I used the brakes to slow and then the very next time it was an almost violent hard right hand pull. It made me think I had lost a wheel cylinder when it happened. Like I said when the minor adjustment didn't work I pulled all four drums and all good so I am leaning to a plugged relief port or perhaps as an outside front runner a collapsing rubber brake line?

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Yes that was my first response after I did the adjustment but nothing noted. Reservoir still full and no wheel leaks of any sort. Like I say it happened without warning and that makes me think it is the relief port in the master cylinder. I did bleed the brakes when I first got the car a couple of years back and rebuilt the rear brake cylinders but perhaps it is time to go through the entire system top to bottom. I am sure the folks at Bernbaum will be happy if I go that route. 

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I will keep you posted. I have a friend with the required tools to complete a major adjustment so will also explore that option. Stay safe. Dave

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Rubber hoses can deteriorate internally without showing anything on the outside.  This can cause fluid to be slow going back to the master and thus pulling from one side or the other. I would replace the flex hoses and see if that helps.

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Parts are on the way for MC rebuild if needed and for wheel cylinder rebuilds if needed and for rubber hoses guaranteed. Will source hard lines at local NAPA and do a system upgrade as not stopping is not an option. I will update everyone once I get an answer and thank you for the input. Dave

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  • 2 weeks later...

 

So to date I have bled all the brakes but this only resulted in a very small initial change in the pulling to the right and the more I used them the more they began to pull. This was at low speeds in a residential neighborhood. I had good volume in each cylinder when they were bled so  I am assuming that all cylinders were activating. This was also supported by the fact that once on jack stands the wheels all locked up when pressure was applied to the pedal. As some of my parts have arrived I have begun a total rebuild of the system and began with removing all the brake lines. Although corroded on the outside there did not appear to be any debris inside the lines and all but one connection to the driver's side rear wheel cylinder released with reasonable pressure on the wrench. Likewise all rubber hoses released under reasonable wrench pressure and using compressed air and clean fine mesh cloth on the other end did not appear to have debris inside them.

Next came the floor boards, the master cylinder and clutch and brake pedals. I am awaiting a new mater cylinder from Rock Auto and in the meantime wheel cylinders are next followed by arching brake shoes and truing drums. Let  me know if you think I have missed something as when things start to go back together it will include new brake lines along with everything else.

The attached photo is the other end of the photo I started this thread with as it is an extended reservoir. The brass tubing from the small reservoir mounted on the firewall goes down and is fitted into a modification on the master cylinder filler cap. Given the workmanship I think this was someone's project not a kit or dealer option.   Dave

master Cylinder.jpg

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I agree completely. My problem was that even after a certified mechanic adjustment and an inspections of all four sets of linings and drums there wasn't any apparent reason for the pulling and it came on very suddenly which was also confusing. I guess I am using this as an excuse to redo the brake system completely to put my mind at rest and make sure I can stop. I will let you know how this rabbit hole progresses.  Dave

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So here is today's update. I have been working intermittently on this problem as unfortunately I have some other time constraints that prevent working on it full time. I pulled the master cylinder, all metal brake lines and the rubber connecting lines front and back. New rubber lines have arrived and are installed awaiting connection to the new metal lines I accessed from a local Bumper to Bumper store about 25 miles away. The metal lines are all sheathed lines and in certain spots the sheathing has to be carefully ground away to allow for brackets or clips to be used. As I am bending these lines by hand I made a very crude but simple bender that has worked very well surprisingly. I used a flat 2" X 6" board about 12" long and nailed a piece of 1" X 1" to it as a straight edge. I then cut three different diameter holes out of an old piece of 3/4" fence board and sanded the edges smooth. I used a wood screw in the center pilot hole to allow the round piece to pivot and mounted it with just enough space to allow the brake line and sheathing to fit. Using the round piece as a pivot I carefully bent the tubing as needed. As I said crude but effective as I did not have one kink out of about 15 bends.

I replaced the master cylinder with one from Rock Auto however was somewhat disappointed that the new master is Made in China despite the picture in the Rock Auto on line catalogue clearly showing the piece stamped "Made in USA." Will see how it works but sending it back through Customs is a pain. I am just finishing the last of the tubing bending and installation and will then move onto wheel cylinders and shoes. Rock Auto shows a 12" brakes system in their listings for wheel cylinders however my system is a 10" system. Do the wheel cylinders interchange? 

Bender.jpg

Rear Axle.jpg

Old Master Cylinder.jpg

Master Cylinder Brake Lines.jpg

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So today I was able to do some more on my brake problem and found some interesting anomalies between the left and front brakes. First the passenger side front brakes have rivetted linings. The rivets are exceptionally close to the ends of the linings and the lower edge of the front shoe actually has a piece broken off by the rivet. The linings on these shoes ran right to the end of the contour with very little beveling on the ends. The wheel cylinders for this side of the car are marked A10585 and the bottom cylinder has 3GL stamped beside the part number and the top cylinder has 1CL stamped on it. A google search did not reveal a manufacturer for this number or any indication what the 3GL or 1CL meant. The top cylinder had a small amount of discoloration on the piston which was easily removed with my finger and both cylinders were clean of any debris. A check I did on one of the forums on this site indicated that the type of piston and brake shoe pins are usually used for aftermarket oversize shoes. 

The driver side shoes had bonded linings on them that stopped short of the end of the shoes on the pivot end but not on the cylinder end. More importantly the wear pattern on these shoes suggested that a portion of the inside edge of the front shoe was either contacting or not contacting the drum and this could account for some of the pulling especially if the right front wheel had full contact to the drum and the left front only had partial. The cylinders on this side were marked 10584 with no other markings available. The cylinders were clean and again appeared to have the piston and brake shoe pins for oversized shoes. The metal stays on the two sets of shoes appear to be the same with a few very minor differences. Neither of the drums appears to be worn however I will have to track down a set of calipers to measure any runout in the drums but it looks like maybe another step in this project will be to get a new set of shoes once the drums are confirmed.

First picture is the end of the riveted lining on the rear shoe right side top edge, second picture is the lower edge of the front shoe right side lower edge. The third picture is the bonded shoe end on the rear shoe front left side with strange wear pattern. I will let you know the outcome of measuring the drums. 

Riveted Shoe End 1.jpg

Broken Shoe.jpg

Bonded Shoe End.jpg

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  • 2 weeks later...

Not having the time to start and finish a project all in one sitting is frustrating. To bring this one up to date I got my front drums resurfaced but found out they were true and well within specs so that was a bonus. I also got the shoes relined and arched so that they are the same on both sides. The Edmonton Brake and Clutch folks were excellent to deal with and very knowledgeable about older vehicles as an interest for all the Alberta members. Once back home with the new parts I put the brakes back together after finishing the new brake line tie ins. That part of the project went better than I thought as the lines were easy to use and molded easily  in the spaces available. The gravel guards were reinstalled however I left the inner fender panel off the passenger side as I may inspect the valve lifters before buttoning things back up. I then filled the master cylinder reservoir and on Sunday enlisted my wife and daughter to assist with bleeding the system. Given the distance from the back axle brake block to the passenger side wheel cylinder I used two lines connected in the middle as the stock parts material was either too long or too short. As luck would have it the connector leaked and no matter what I did I wasn't able to stop it. On Monday I got to the parts store and purchased the too long piece of stock brake line and will loop it to make up the difference. More to come.

brake reline.jpg

Drum Reline.jpg

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All bake linings should be chamfered onboth ends. This helps with the run out of the lining to the drum contact. In the pictures that you posted the one with the broken end is an issue and the lining might be moving.

 

We have noticed that on some of the newer bonded brake linings they do tend to get hard or glazed and then this will cause a pulling of the car.  i prefer the old riveted asbestos linings because they actually stop better

 

On the older cars that had the single piston with the steps down two sized pistons they short linig was always installed at the rear of the shoe and also at the bottom portion of the shoe.  The Lockheed brake system worked properly with this setup.  everyone was later told that the long shoe onthe rear shor on the from but the lockehhed brake are not self centering.

 

read your service manual to see how the brake linings were installed on your cars.

 

Rich Hartung

desoto1939@aol.com

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Buy a brake line flaring kit so you can shorten lines as needed. Inverted brake flare tool kits are inexpensive to obnoxiously overpriced hydraulic flaring kits. I have both.i do a lot of brake work.  If you coil a brake line, the coil should lay horizintally not vertical. 1/4 line will trap air if you make a vertical coil. 
 

has your suspension been thoroughly inspected? Front and rear. If your brake pull still haunts you,it could be a control arm shifting under brake load. 

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4 hours ago, MarcDeSoto said:

I wonder why the original engineers of hydraulic brakes didn't think of dual reservoirs for the MC?  It's such a safety plus. You would think they would have thought of it, so that if your front brakes sprung a leak, you would still have your rear brakes!  

This exact thing is one reason I am upgrading there.  I have actually had a rear wheel cylinder blow it's guts out and cause me to loose all braking.  In a panic I stomped on the parking brake pedal and promptly tore the end of it off.  Fortunately I didn't hit anything but it was a scary moment there.  Now in a nod to what DodgeB4ya and I were discussing in another thread I had put a boneyard axle assembly in and this was the test drive, I neglected to inspect the boneyard brakes that were on it.  This was way back in my youth at a time when experience hadn't yet slapped the know it all out of me. 

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I had a younger brother who in his college days was so poor he couldn't afford to have his VW bug brakes fixed.  He actually drove the car without brakes, using the hand brake and diving into the shoulder when a car suddenly stopped for something at the bottom of a hill like a red light!  

 

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  • 1 month later...

So here is the latest on my saga. I completed the new master cylinder and brake line project successfully. I have cleaned all wheel cylinders and measured to make sure they are correct and reinstalled on the car. Front brake drums were turned and shoes relined and arched and everything put back together. I borrowed a gauge from a friend with the same car and began the process of aligning the shoes within the drums to get a major adjustment process complete. The gauge is home built but does a reasonable job of setting the shoes into position without the drum so that minor adjustments can be made once the drum is back on. The process begins by backing both shoes off completely. You then adjust one of the shoes, either toe or heal, so it just begins to rub on the drum. You then remove the drum and spin the gauge onto the spindle. The gauge is adjusted to measure that distance and you then recreate it at the toe and heal of both shoes through a series of cam adjustments. Once you have the shoes adjusted so that you have the .006" clearance heal and toe you then reinstall the drum.  Once the drum is back on only a very minor adjustments could be needed to true the shoes to the drums.

 

All was going well until I got to the right front drum. I had backed the shoes off completely and then reinstalled the drum to begin adjusting a shoe to get it to touch the drum. Prior to any adjustments being made I spun the drum on the spindle, bearings in place and lubricated. I found the drum continuously stopped in the same spot each spin. There was a slight grinding noise when this occurred however I could not determine where the noise was coming from. I thought perhaps the backing plate was warped however could not get yellow paint to transfer from the drum edge to the backing plate. I also thought perhaps one of the shoes was off set or angled on the backing plate but again could not get paint to transfer from the edge of the shoes to the inside of the drum. There are no wear spots visible on inspection and I believe the drum is true. As the right front brake was the source of my original problem it makes me wonder. Bearings are almost new and have no indication of being heated or damaged. 

 

Has anyone experienced this type of situation and have a suggestion? I am at a loss and aside from adjusting the brake like all the others and taking it for a drive I don't have many options. Obviously if I have a grinding situation every revolution of the drum I am not really thinking that is a smart move.  Dave

Drum Edge.jpg

shoe edge.jpg

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