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Hope this makes you feel even better...I was 60 when I got mine and thanks to the guys on this site Iv learned a heck of a lot about Macks....Ask loads of questions and remember the most stupid question is the question you dont ask......because the answer may be the one you needed all along....... Paul

That little bit of spline wear shouldnt cause the clutch to drag. Removing the input shaft is easier with the bell housing off. But then you will need a new gasket. It should be fine like it is.

Nothing like chowing down on a good sausage ????

What's everyone's thoughts on the new mack keystone? I like it

I already have a few posts ago As I said, Im not getting into proving I'm right, just saying it as it is Paul

Phase change is phase change! Explain "separating" and why it happens there and not elsewhere.

I can’t get enough of that sausage sandwich truck

The coolant isn't boiling, it's separating Very different Paul

Hopefully it doesn’t take you that long to start making good progress on it as it took me

Double clutching? WTH is that.... 😆 I'm either starting out or not near the clutch pedal.

The splines are worn a bit. It takes "special" tools to replace it or I would get one. Or I will have to buy more $400 tools for one time use...🤦

Liquid changing to gas, has a term, it is the boil point. If you are boiling at the return from the radiator, you are already overheating before any coolant has entered the engine to cool it. At 50/50 and atmospheric that point is around 223 deg F. And this is on the return side of the radiator. Where as the de aeration tank is where the pressure cap is and also directly connected to the lower pressure side of the waterpump, that is above atmospheric, often around 10 psi.

Awesome 😎 I feel good about it for sure.

Very true Joey When learning and someone misses a gear, the first thing we naturally so is panic and shove the clutch to the floor OOP's Makes it even worse and we try even harder Oh dear, we need to learn some how Paul

I was 38 when I got mine …. I’m way older now

I have a lot to learn for these old macks I am on 39 but love the way they look and love a challenge especially if I can get it going.

The coolant doesn't vapourise, it turns into two different gasses and this actually happens in the pump impeller Paul

Scrapple is the floor sweepings from the sausage plant boiled in corn meal, with lots of spices and black pepper. Drained and allowed to set up in a loaf pan, then sliced and fried on a griddle. Every PA Dutch grandmother had her own recipe which she passed down to the next generation.

So, how low does the pressure have to be for the coolant to vaporize? As you say there isn't "suction" only pressure below atmospheric. If you look how low the pressure has to be for the coolant to turn to vapor, it is well below what a centrifugal pump can produce. The pressure cap holds the "suction side above atmospheric, the pressure side can be as high a 46 psi in the block.

I could be wrong, but that cover and input shaft looks worn from the picture.

So cavitation occours when the liquid, in this case water, seperates into gasses Oxygen and hydrogen in the case of water This happens when the delivery side of the pump isn't restricted enough or supply side is to restricted Pumps pump less when this happens, like Joey sort of said in different words, centrifical pumps can't pump air So how to stop this happening in motor, run the right thermostats, don't over rev, maintain a good pump So why isn't air trapped in the pump housing as Geoff suggests As soon as the pump starts half of the pump or there abouts is under a lower atmospheric pressure So what does this mean ? What's easier to shift, a bucket of air or a bucket of water ? A bucket of air of course, so the low air pressure causes the air around the pump to try and escape and the only way out is through the on the delivery side So why are some motors not subject to cavitation and others susceptible Pump design and location on the motor has a lot to do with it Detroits pump on a 2 stroke is small diameter and down low, this means it makes less pressure or perhaps it makes smaller pressure difference between suction and delivery Macks are also better designed So the air on cavitation is coming from the liquid been shifted, not staying liquid all the time There is no air getting into the motor, the liquid in the motor is changing state and once the liquid passes through the pump returns to liquid again The cavitation is like water hammer on the pipes in house, turns from liquid to gas and back again, over and over again The coolant system has a type of water hammer No wonder some designs of motors are susceptible to this and it's hard to stop So trucks got more power and bigger coolant systems, which in turn leads to higher coolant flow, this causes cavitation Many a Cat earthmoving machine suffers from this when thernostats are removed So I'm not having ago at anyone, but it's very clear that some of our standings are not correct on pumps and shifting of liquids and how a centrifical pumps actually work There isnt a suction side, even though we call it that There's a low pressure and high pressure side on a centrifical pump Positive displacement pumps have a suction side, so the supercharger on a 2 stroke Detroit is a positive displacement pump Anyway enough waffle from me I can explain further if needed but won't have a big long drawn argument trying to prove what I'm saying is write Happy days everyone Paul

Probably if you look at the pressure cap on that system, it's on the higher scale. So it needs a good robust line to do the job. Some system have a lighter hose for that, but also operate at lower pressures. Gotta have the vent action going on as the coolant expands and contracts during the cycles .

Thats because a lot of drivers do not understand the 3 stages of the clutch pedal.. as a driver trainer, i spend a good bit of time explaining the 3 stages. As to be expected, new truck drivers slam the clutch to the floor as if they are driving a car. It takes them a bit to understand how to use the middle part of the clutch stroke for double clutching...

most folks don’t understand the use of the clutch brake so yup I agree with that choice! Myself I would use a two piece eaton brake but the set has to be perfect! If you don’t set and use techniques correctly you can ruin them with one poke to the floor! Don’t ask me how I know!😡

They dont look like spring parking brake pots to me.Look like the brake pots on the front axle of our Mack... Paul