Re: Remote brake fill kits

Posted by d c On 2014/8/22 17:13:01

I agree with you on many points and appreciate your experience rebuilding the units and the service life you are reporting. It goes without saying improper service procedure, seals misinstalled and pitted plunger shafts will all cause failures and if individuals have no experience mechanically and cannot tell if a bore or shaft is in a serviceable condition to hold an air or hydraulic seal, they should not be attempting a rebuild. Those instances however do not explain failures of professionally rebuilt units. Some reporting multiple failures of such units at low service intervals.
Taking the 55-56 service manual information into account and the info I have referenced from other sources, as well as my experience in this area and my dealings with manufacturers justifications such as "some seepage,leakage,sweat etc etc etc is normal and desired... I do believe I have the backround to make an informed decision on the facts in question. Can you give me the source of the statement "some leakage is desired to lube...", and, " splash and flow into the relief port is as designed by the manufacturer" as I did not see those in print anywhere. The 55 service manual is very specific on the amount and type of products to be used on the rubber cup seal (primary), Wicking, Leather packing, and vacuum canister inner bore face. The fact that the leather cup seal(secondary) is installed with NO liquid or lube of any kind with just the residue left after the primary seal installation has swiped the hydraulic plunger shaft virtually dry is quite notable. If the leather vacuum packing seal is damaged when exposed to prolonged brake fluid contamination why would the leather secondary cup seal fair any better? As an additional note, Cadillac used the same BTV but installed it higher and horizontal on the fire wall. It is telling to observe their cover has a dipstick and a relief port tube which extends the port up via this external tube rising vertically up from the cover and bends into the air space high at the cap attaching area. We only need to verify that the original Cadillac lid is vented either at the cap or the dipstick handle, and that the "Full" line on their dipstick is at or below the lid mating surface. This can be done with a simple ruler measurement on the removed dipstick and compared to the tube-lid assembly. If anyone out there knows a friend with an original Cadillac could they reply with this info? If these 2 assumptions can be confirmed, there is no doubt bendix meant for that port to be exposed to atmosphere and not subjected to any splash or back flow of brake fluid. (Unless a 50s Cad can accelerate like a top fuel dragster or can stand on the bumper!)
It is also notable that during final reinstallation of the unit and the toe board into the vehicle that the service manual emphasizes careful alignment of the pedal and shaft. Upon close examination of the unit, the only thing keeping the the hydraulic plunger running straight at a perfect plane into the master and perpendicular with the seal lip is the steel washer and fiber washer and guide hole in the vac canister . If these are worn may this allow the plunger to ride crooked on the seal?
I want to stress that I am in no way suggesting any changes or modification to this or any brake system. Its functionality must remain exactly as the manufacturer intended it. It is also a fact that most drivers of these vehicles are ageing and if the design of a system makes it difficult to physically check a fluid level or condition as often as necessary for safety, then a modification to "see" the brake fluid is welcome but without a manufacturers specific instructions on a "relief port" we must determine its intended condition using all information available. It is unfortunate that the Cadillac cover protrudes and the dipstick is on the wrong side. The 54-55 Olds cover is flat with a dipstick on the driver side and could be a partial solution in that it allows a check of the level frequently but does not address the relief port however if the above items can be verified a proper remote fill can be utilized with the extended vent tube and LEVEL, CONDITION, and SEAL STATE OF HEALTH could be checked before every drive with a simple lift the hood,look and listen making driving these classics as safe as it can possibly be. Any thoughts?