Geoff Weeks

It is a double edge sword. Easy to get in too deep.

I was alerted to this auction that is close to where I live. Some old Macks and other brands, dating back to the teens though more modern times. I have no connection to the auction. I will not be able to research any listed truck for anyone, but may make it to the inspection day if things work out and if I do could take some pictures for someone interested in something not shown. https://www.vanderbrinkauctions.com/auction/online-only-antique-tractors-vehicles-parts-more-the-dennis-bates-collection/ Again, I can't promise I will make it to the inspection day (I am on jury duty call in) but if I go, I would try and take some pictures if someone had a truck they were interested in.

Check the breather line (not the vacuum line) for a constant draw of air into the hydrovac. If the the control valve is faulty, there will be a constant air intake anytime the engine is running. Under no braking, both sides of the piston are under engine vacuum. If the piston is leaking, there will be no intake of air when the brakes are released, but continuous air intake when the brakes are pressed. In normal use when the brakes are pressed, an amount of air is allowed in but should stop if the pedal is held a some position between the floor and released. The hyd cylinder section can also leak brake fluid internally so even though the U cup moves it doesn't build pressure beyond what the master cyl already provides. Also don't overlook the brakes themselves. My Hy-Torque style brakes on the rear have siezed up requiring complete disassembly and cleaning + lubing of the pivot points. Once that was done, the brakes would plant your face on the windshield empty or loaded, if you jumped on the pedal hard. Needless to say, these units require a good vacuum source AND a good source of clean air. Some units have their own aircleaner (either dry or oil bath types, I've seen both). If the air intake is not filtered, all bets are off of how much dirt and dust has got inside a clogged passages, or even mud dubbers. Some installs have the air inlet plumbed to the clean side of the engine air cleaner. There should be two bleed screws on the Hydrovac itself. You start by bleeding to the screw by the control valve, then the one on the outlet, then the furthest brake from the master and working your way back to the closest brake. Another problem I see, is people don't use vacuum brake hose (which is required by law) but heater hose or hyd hose that is not rated for vacuum brake service. This can collapse, and prevent proper operation. I use as much "hard line" either steel or aluminum, and only use short sections of vacuum brake hose to make connections. If the truck already has steel vacuum tubing (1/2 or 5/8") make sure it doesn't have pin-hole rustouts in it.

this has a bunch of interchange numbers to track down: https://www.webbwheel.com/webbipad/pdf_files/102-(65511).pdf Take a bunch of measurements and see if another inboard spoke drum can be machined to fit that application. 16.5 x 5" drums still show on a catalog that is a few years old.

Original 3rd series could have a leather piston, so neetsfoot oil would be appropriate, but COULD have a rubber one, in which case jack-oil would suffice. On the hydraulic side, brake fluid should pass through from the master to the wheels. If it is leaking brake fluid into to vacuum line back to the engine, then you have to address the hyd side of the hydrovac. Again, I have 80+ year old unit that are still function. WHAT ARE THE SYMPTOMS???

Again, What are the symptoms? Oil will not solve a problem. It is PM. It can not cause no brakes, only no power assist.

That was the name I was looking for!

What are the symptoms? I have 80+ year old hydorvac's and they still work. You have to bleed them in the correct order, or they may not function properly as air gets trapped around the vacuum control valve if it isn't bled 1st. Also another "must" is a check valve in the vacuum supply between engine and hydrovac. It keeps combustible gases from being drawn into the hydrovac when the engine is shut down

https://powerbrakes.com/hydrovacs/bendix/ https://www.accupart.com/vacuum-brakes/bendix-type/hydrovac/?page=4

Not the way I read it. 4 six volts to make up 12volts so two sets in series the sets in parallel. Truck is 12 volt.

I drove from Gillette,WY to Illinois on the front with the interaxle driveshaft out. I was loaded but not to the max GVW.

From what I remember before deleted, he was driving in the local area where the previous owner had it. The latest from him before delete was he made the 3 hr trip with new batteries, so last posted it was not at his place of business.

If you are asking if I am, no! However a 40 year old cooling system that has been neglected to the point it takes 8 flushes to clear it is most likely. Water pump pull is easy, but I would be surprised that a water pump alone would cure the problem. The age of the radiator has not be established to my knowledge, but if more than a few years old, it would be suspect. Human nature to look for the easy solution, but a well maintained will be clear inside after years of running. One that isn't will be gooky, this one is (or was) gooky.

More likely to be plugged tubes in the radiator, with a history of 8 flushes to get the clear water.

A 12V71 was 450hp or slightly less than 2 6-71's (238 hp). The 855 Cummins was up to 475 hp in Big Cam but 400-450 was the best configuration. When it went electronic (N-14) power was much higher. That said, in its time period it was one of the highest Hp engines people stuck in trucks, originally it was done as a industrial engine re-power, and later it may have been factory for turnpike doubles and the north slope oil field. Never operated or worked on one. The K Cummins (which I have worked on) was a better big power option. but $$$

All I can say, a year later, is the P/O is one of the most understanding I've ever seen. If I sold something and it was still on my property, either you would be paying rent, or it would be re-sold, or hauled for scrap. Sorry, but I think that must be said. About a year ago, you had said you were going to have it towed. Put it on a low-boy with over height permits if needed and get it where you can work on it, or cut your losses and move on.

You have enough there to take to a fab shop and have him make you one, either out steel or aluminum, steel would be cheap and easy.

4"x 15" is the common size. I'd give Vanderhaag's a call and see what that one is. One down! They may or may not, have another for the other side.

On my '42 all the original switches and pull cables were replaced with modern stuff. My '48 is all original. Replacement cab for the '42 has most of the orginal switches but one of the pull cables is gone.

Military and diplomatic families abroad are citizens of the country that their parents are. Yes, children born to parents that don't fit those two exceptions are considered citizens in most countries. Otherwise, none of us would be US citizens. Somewhere in your past and mine, our relations came from elsewhere, and their offspring became US citizens, If not we all would be citizens of where our ancestors came from! The law is clear, if born here, and subject to US law (not diplomatic or guest military who are NOT subject to US law) then you are a citizen. "Sins of the father" don't get put on the shoulders of the offspring. How do you know how a kid born today will vote when they become of age? Most peoples views come about during their maturing, and it is impossible to guess how someone will vote 18 years in the future, regardless of their parents view.

Using the factory headlight switch (delco) ? I have a back-up on a switch but I am looking into what it would take for a switch on the shift rail. Have you done that or just manual switch like I have?

Little seaching came up with this: https://vanderhaags.com/detailview.php?part=25343018 Newer type brake "S" cam but might bolt in place of what you have now. "T" brakes were obsolete over 30 years ago, so finding new replacements might be impossible. Used might be the best chance, or converting to something more modern. edit: blowing up your picture, it may be an S cam that you have. So that is one found. What size brakes do you have?

I believe what you have is a Rockwell "T" brake. At least it looks like the "T" I had on my '89 Cabover. What I don't know is if the backing plates are universal or the backing plate is unique to the Mack axle it is on (If you do have a Mack axle and not a vendor supplied axle). Rockwell Brakes, Field Maintenance #4.pdf https://midwestwheel.com/marketing/08Brake-Shoe-ID-Chart-and-Air-Disc-Brake-ID/#zoom=true

From and old post.

Well you are dealing with something old and odd ball. If the adjusters are worn but serviceable, then they go back in, if they can't be cleaned up and serviceable, or the teeth on the wheel are badly worn, then you'll need a machine shop to copy the old parts, and make new. I have done that before, and as long as the machine shop is good, can be the best bet. I had to have a part made for an adjuster on my Saab, which has the hand brake on the front caliper. Grand total for 2 adjusters was $70. Other would swap out the front and rear brakes (caliper, disks and hardware) (requiring an axle swap on the rear, new parking brake cables etc) to "update" to the system that parts are available for. When working on old, not available stuff, you have to think outside the box, and keep in mind, that if it was made by man, it can be re-made by man. The type of machine shop you want is a small shop that does repairs on older stuff, not a large production shop. Ask if they do the kind of work you need or can recommend a shop that does. Your parts look "all there" so at least you have patterns to work from. Shoes can take linings, and cyl can be rebuilt.