buick man

Chris .... I just detailed and explained what a proper 57 Buick pedal should feel like ... what did you miss ? Adam ... Yeah it is a lot to process and perhaps you were just lucking in the past. Like I said it is either the parts : original, cleaned and reused, or new and funky spec or something your doing, missing or over looking. Most likely the master cylinder and rod shaft interface. It is all about the sealing around the shaft at the master cylinder. But if you confidentially feel it has nothing to do with you or the components, go turn up the shoes into the drums up almost tight and see how your pedal feels ... if that cures pedal feel issues then it is most likely not your mc and while under vacuum the pedal rebounds properly as explained then it is something past the mc components and is either your brake lines themselves that although appear o.k. have an existing internal unseen failure problem. By snugging up the shoes into the drum to a certain extent you can isolate the shoe drum interplay to determine if that is the problem. 🤒 Edit: btw the photos shown above are from a tear down I did some years ago. The entire brake system was working just fine like all the 57 Buicks I had before, just removed, disassembled, cleaned the parts up and reassembled so the photos depict what the parts look like. Any cracking or dry parts which most likely won't occur unless the unit sat for years dry, then just clean up the parts and reinstall paying attention to how the shaft seals are doing their job. Doubly inspect how the seals look upon contact along the shaft/piston. Regarding the piston, make sure it is slightly just damp with ATF not soaked. No need to butter up the inside of the tank. Make sure the spring stays in position as you insert and pull back on the piston to check for binding or uneven retraction as you withdraw the piston and then pushing back in ....

Here are some more component photos to consider : As for the master cylinder itself as stated above is a metal reservoir chamber but the plunger head rides and seals via multiple rubber and metal components all riding on the just the plunger rod itself as the head is metal not rubber and plunges into the reservoir as a mass of displacement to cause the brake fluid to seek an opposite dynamic in response to the metal plunger rod. This then allows for greater displacement to occur with minimal counter force concentrated on the circumference to the small plunger shaft itself rather than conventional master cylinders that rely on the larger sealing areas needed and integrity of a cylinder wall of a rubber plunger/metal wall cylinder scenario. With that said, the shaft however needs to have it's rubber components located correctly and the spec clearances of the replacement rubber components have to be tight and the material used of solid integrity. If not this area of the master cylinder is going to give one problems on a rebuild pics 8 & 9. Placement of the metal strainer spacer as shown at the end of the wooden handle as being removed has to be non corroded and placed and seated correctly into the master cylinder on rebuild pic 6 & 9. If the both the master and plunger cylinder are correctly reassembled, lube and rebuilt with solid close tolerance quality components, with correct toque sealing the you should have a solid pedal upon driving and almost instant brake response at about 1/4 deflection of the pedal. If one wants to improve upon what is already a solid pedal feel, then the installation of metal braided DOT 4 flexible lines can be installed on both fronts and rear over axle line. Edit: The metal braided lines will dramatically reduce the psi reflex rebound that rubber only lines experience upon braking. In short rubber lines bulge out and this increases drop foot pedal travel where as metal braided teflon lines prevent this and contribute by reversing this rebound dynamic thereby assuring a more solid pedal and thereby reducing drop foot pedal travel.

Just my opinions here... Adam in all practical probability it is not the brake shoes and it is not the master cylinder itself as it is just a hollow block as it essentially serves as a hollow metal reservoir ... but wit this system it is all about the rubber seals, metal ring positions, amount and type of lube used upon reassembly. Also you may through no fault of your own have a crappy rebuild kit to begin with ( think type of materials used and the finished tolerances they are molded from ) or possibly you are creating something in how you are reassembling the components .... When you rebuilt the vacuum diaphragm did you apply any thing to the rubber comports that the rod slides through and/or how much did you use ? Did you apply anything to the walls of the plunger tank as shown in pic 7 ? What type of plunger material are you using leather or plastic compound provided in the rebuild kit as shown in pic 3 ? The bleeder line can leak internally new or old so take off and test it pic 1 & 2 . If you did apply something to the either the leather or plastic plunger how much of it did you apply and did you make sue the internal ring spring was not walking out of the leather or plastic when you inserted it into the plunger drum ? One can easily reverse the reassembly of the satellite clip rings pic 8 & 9. The cinch brass plug can be too loose or too tight when re-installed pic 6 If completed correctly and your reservoir vacuum tank and associated vacuum lines are all sealed and not leading, then if the car sits for ever you should still be able to get a hard pedal at about 1/4 of the way down and continue to do so even after multiple pumps. If not then some area, item/component, lube is either not installed right, overly lubed, reversed or is not sealing correctly or leaking or as stated you have a kit that has loosy goosy spec tolerances made of cheap component material.

... now now Lance, stop pouting just because you have a couple Roadie's ....

Ad Reads: Current owner for the last 24 years. Extensive restoration work completed. New top, all chrome replated. Excellent interior. Black paint with burgundy interior and tan top showcases this beautiful Buick Roadmaster convertible. Fireball straight 8 cylinder engine, dynaflow transmission, power windows and power top.

..... yeah, yeah you just wanted the garage more than the car ... just make damn sure your new shop rafter design allows for at least a 14 headroom for the bendpak lift ... 👹

It is after all and among a complex array of other things a matter of age dynamics ... today looking back I am amazed really at all the things I was able to take on in far less desirable conditions and circumstances then I would even consider doing today and accomplish them in my 30's with little thought but the task at hand .... 30 + years later I am being humbled and beginning to slowly become aware of and realize my new ever emerging limitations to my previously once long held perceived identity and capabilities. A form of elder adolescence if you will. Getting older sucks no doubt about it but on a more positive note that is why they make easy chairs and the internet for watching and connecting with others such a satisfying joy to behold.

WOW on steroids ... Adam did you do all the transmission and rear end R&R yourself in your garage or did you have that done somewhere else ?

Jim: .... Will do my best ....

Jim: Just a thought and some ideas... but looking at the factory box it appears to be of plastic composite material construction which would easily render itself for a mock up in fiberglass since the original Harrison unit is rectangular ... Consider making yours out of fiberglass via making a proper jig setup. This could be done by constructing a take off by using the general measurements from one still installed in the engine bay and using a cardboard mockup or obtain one on loan and have a lab 3D Model it : :

... Also note that factory spec rebuild float adjustments as stated in the old factory book does not always equate to an optimum float movement range spec due to the cause and effect of our current pump alcohol based (gas-o-hols, corn-hols etc. ) that is currently available at the pumps and can cause idling, loading and start up issues.

Selim.... Just a few words and heads up comments .... If you are planning on actually rebuilding your dynaflow and not just attempting a " gasket n googh " rebuild you will need spec's on all the factory component wear variances, clearances and know how to mic the components out properly and where to look for spec tolerance wear. You will also need operating PSI ranges at various rpm ranges for the pump and system components in all it's various ranges. ( i.e. I say ranges because the dynaflow does not have gears but pump psi ranges ) before and after assembly. To correctly determine current operating and performance issues before tear down and then once again upon complete reassembly, factory spec pressures at designated rpms need to be determined. This will require an adequate transmission stand and at least 5 high pressure gauges and a couple auxiliary test gauges and a way to spin the dynaflow pumps, because a dynaflow is one big pump machine and operates on various rpm pressure created and not gears and clusters. Please Note: Many if not most so-called rebuilders do quite well with Torque Flights and Ford o Matics etc ... but the dynaflow is a completely different creature and many lack the proper dynaflow rebuild experience and test equipment/procedures which often result in gasket and googh rebuilds while not actually addressing wear and performance issues nor have the ability to know how to adjust for factory spec performance.ranges So you get back a sealed but still tired old dynaflow ..... Here is a good link to Mudbone's rebuild of a 55 Dynaflow. Click on the YouTube link at the bottom corner and it will take you to his rebuild series. Not much different from yours except for internal pumps and stators but the rebuild and testing procedures is much right on. Also if you do not already have a copy get a designated dynaflow factory rebuild book that tends to expand much further than the factory shop manual.

Jim: Just a thought but why not cannibalize an existing system since 95% of everything will bolt right up then rig up a new and improved compressor that is optimized to run on current refrigerant and take your fan blower motor out and have someone install a sealed bearing plastic unit that would ensure quieter operation at higher speeds. You can also then fabricate additional internal under dash pathways to convey directional air flow where desired. Install a Gen Alternator to push the loads while still looking like a generator. That way all your controls will be period correct and performance modern correct ....

.... In the past yes I have and remember " without oil leaks " is only a direct result of installing the upper seal without mangling the seal, twisting it or cutting the seal off at the surface of the cap not allowing for an 1/8 inch protrusion into the bearing cap. Research and school yourself on the technique. Thus the reason for lowing the crankshaft in vivo is to allow upper clearance to insure proper placement. To make the task easier one can use a number of tool aids available to make the job easier.

Russ might have that install on his website under articles. If he does not, installing is not that difficult. You can purchase a seal chaser on line that is essentially a plastic tool with an end that allows you to pull the upper seal up and over the top of the journal. You want to also slightly drop the center and the next main cap journals by loosening the bolts on each a few turns which by doing so allows the crank to come down slightly enough to give you more upper access room at the rear main journal working area. Loosen the center main a little less then the next rear main so the crank angles down slightly to the rear. Also when installing the rubber type seal don't cut the seal off flush with the upper journal face but allow about an 1/8 of an inch to protrude at each end out so when you put up the bottom half of the rear main cap it will compress upon torque and give a positive seal. Then bring the other journals bolts back up and torque everything. Torque by torquing to 1/2 the spec on each journal bolt, then come back around again and finish the job by bringing each bolt up to full spec torque. In other words, just don't torque each bolt to max the first time. Also do not apply any grease on the back side of the bearings if one should separate from it'a cap journal as this will allows the potential for spinning of the bearing to occur within the cap later which is not a good thing. If you find that lubing the face of the bearing and or crank journal surfaces is appropriate use assembly lube only on the contact faces. Contact Russ as he is helpful.