Barry Wolk
05-23-2022, 09:34 PM
Both of the T-V housings I have are badly pitted. One of them came to me on Al's '57 and it's pretty messed up. The stock stainless steel ram had been replaced with a chrome-plated steel rod that had pits in the chrome that tore up the seal and let moisture-laden brake fluid into the vacuum chamber. It badly pitted the surface at the very bottom. The casing is made of a steel that rusts instantly when it comes in contact with water.
The other one I have came from Mad Scientist's rolling Mark II laboratory. Mad claimed that his parent's car was an Introductory Unit. As such, it was an early car. The photographic evidence shows that many cars were fitted with Zinc-coated housings. I believe they were zinc-coated as the inside of the TV needed the rust protection. Mad sad that this unit was unused, but it has all the tell-tale signs of use. I think it was the original T-V from his folks's car and the replacement is what was on the car when he altered it.
This is the condition it was in when I opened it 20 years ago.
https://hosting.photobucket.com/images/gg18/barry2952/283495557_281892697411492_7697235477131372597_n.jp g
I media blasted the interior to remove the rust, but it also removed the original zinc plating.
https://hosting.photobucket.com/images/gg18/barry2952/280438005_724349405428888_3324163217995360211_n.jp g
I found little pitting in the actual part of the cylinder the vacuum shuttle moves within, but there was bad corrosion at both ends that caused endless vacuum leaks.
I started off sanding the interior but found that honing stones from my knife sharpener worked well, and quickly revealed the corrosion ring. I started with 320 grit and worked up to 1000.
https://hosting.photobucket.com/images/gg18/barry2952/281824787_734609667566702_6057644669618596091_n.jp g
Now that I have the rust remove I am going to attempt to replate and use zinc as a filler for the pits. Plate, sand it all off but what's in the pits, rinse and repeat until pits are filled and the triple-plate the inner surface for a final polishing. I'm finding this is a common repair for pot-metal parts. This should protect the interior and give it back a smooth surface. I was looking for an appropriate-size bucket to plate it in. My assistant came up with the brilliant idea of using the booster itself for plating the inside. Plugging the holes in the end the canister can be filled up with the plating issuer and hooked up to the negative of the power supply and the anode of solid zinc would be suspended in the middle of the pot. The zinc should transfer from the anode to the canister and leave a zinc deposition on the inside.
With a pit-free lining and a new leather seal soaked in Neets Foot oil the power brakes should work well.
The grinding did remove most of the pitting. We'll see how may coat of zinc it will take.
https://hosting.photobucket.com/images/gg18/barry2952/IMG_3572.JPG
One on the biggest problem I've found with the TV is its inability to dock the ram, setting the tip switch that allows the chamber to fill from the reserve. That is surely the job of the large coils spring that returns your pedal to position. I've found a difference in the heights of these springs been relative to their strength. I plan on solving this malady by installing a spring spacer that's 1/4 of an inch thick effectively lengthening the compressed spring, giving it more strength. I have found that stretching the spring only works for a short period. That should be a permanent fix.
The other one I have came from Mad Scientist's rolling Mark II laboratory. Mad claimed that his parent's car was an Introductory Unit. As such, it was an early car. The photographic evidence shows that many cars were fitted with Zinc-coated housings. I believe they were zinc-coated as the inside of the TV needed the rust protection. Mad sad that this unit was unused, but it has all the tell-tale signs of use. I think it was the original T-V from his folks's car and the replacement is what was on the car when he altered it.
This is the condition it was in when I opened it 20 years ago.
https://hosting.photobucket.com/images/gg18/barry2952/283495557_281892697411492_7697235477131372597_n.jp g
I media blasted the interior to remove the rust, but it also removed the original zinc plating.
https://hosting.photobucket.com/images/gg18/barry2952/280438005_724349405428888_3324163217995360211_n.jp g
I found little pitting in the actual part of the cylinder the vacuum shuttle moves within, but there was bad corrosion at both ends that caused endless vacuum leaks.
I started off sanding the interior but found that honing stones from my knife sharpener worked well, and quickly revealed the corrosion ring. I started with 320 grit and worked up to 1000.
https://hosting.photobucket.com/images/gg18/barry2952/281824787_734609667566702_6057644669618596091_n.jp g
Now that I have the rust remove I am going to attempt to replate and use zinc as a filler for the pits. Plate, sand it all off but what's in the pits, rinse and repeat until pits are filled and the triple-plate the inner surface for a final polishing. I'm finding this is a common repair for pot-metal parts. This should protect the interior and give it back a smooth surface. I was looking for an appropriate-size bucket to plate it in. My assistant came up with the brilliant idea of using the booster itself for plating the inside. Plugging the holes in the end the canister can be filled up with the plating issuer and hooked up to the negative of the power supply and the anode of solid zinc would be suspended in the middle of the pot. The zinc should transfer from the anode to the canister and leave a zinc deposition on the inside.
With a pit-free lining and a new leather seal soaked in Neets Foot oil the power brakes should work well.
The grinding did remove most of the pitting. We'll see how may coat of zinc it will take.
https://hosting.photobucket.com/images/gg18/barry2952/IMG_3572.JPG
One on the biggest problem I've found with the TV is its inability to dock the ram, setting the tip switch that allows the chamber to fill from the reserve. That is surely the job of the large coils spring that returns your pedal to position. I've found a difference in the heights of these springs been relative to their strength. I plan on solving this malady by installing a spring spacer that's 1/4 of an inch thick effectively lengthening the compressed spring, giving it more strength. I have found that stretching the spring only works for a short period. That should be a permanent fix.