Geoff Weeks

There is no replacement for a functional radiator, the sooner you accept that fact, the sooner you'll be back making money. Heat can cause blown head gaskets, liner problems, and can ruin an engine. Try overhauling the engine for $2300, and then be right back where you are now. When I did mine, the out of chassie kit cost me $1500, and the radiator $2150. I knew the $1500 and my labor would be wasted if I didn't make sure the radiator could cool it.

either new core, and you know what you have, or used and its a roll of the dice. You need to cool the engine, what other option are you expecting?

5-7 years ago, mine cost $2150.00 So sounds about right. You can't "cheap out" and have long term solution.

Sorry to hear that. I went through the prostate dance 2 years ago. Mine is in a jar somewhere. I thought if you were going we could finely meet. We have been conversing since the old ATHS days, when my town was going to seize my Dart.

Terry, are you going to the inspection day?

Mack rears have a smaller "bowl" that sticks below the axle housing (being a double reduction rear) which can be a real advantage when working off road in rough work sites. For fuel hauling,on road, there is no advantage to the design, more bearings and likely more heat when run down the road. I worked on some Macks, but I had IHC, Eaton and Rockwell (Meritor) and found that all were good, and all had something that could have been improved. The Rockwell's were the only ones that outright failed on me, but they were put though a lot, before they failed, sometimes hauling 168K GVW on 40 K rears. All will work and if cared for give good service, but I think single reduction for on highway service would be the best. If the interaxle driveshaft is designed properly it doesn't cause problems or vibrate, despite being at angles, that is what U joints are designed to do. You have to get the pinion angles correct, so the joint angles are correct.

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.