mrsmackpaul

I'm impressed by the this whole operation Keep us posted, this something most of us will never see Top job Paul

So not knowing what I'm looking at here, this tool pulls the bearing offthe shaft and out of the box while leaving the shaft installed Is that correct, pretty smart idea if my understanding is correct I guess the other side of things to think about is, if you have a issue in the box your unaware of, this is the time to have a look while it (the gear box) is on the ground out from under the truck But.that is a smart tool if my understanding is correct Paul

Steady on there Geoff, that's a pretty serious accusation I have tried my best to explain something to you, I never claimed to of been a expert in physics I never finished high school However, that doesn't mean I'm stupid either, so perhaps stop the insults I can't teach someone that doesn't want to learn, someone can't learn if they think they know everything A simple comment about is air trapped in a pump housing turns into this mess Ah well, maybe someone has learnt something here, maybe they are convinced now that I am dumb ass and don't know my ass from my elbow due to not having a proper education in teaching and thermal dynamics Dunno ??? Not a lot more I can add here, I have tried my best Back to 300+ Paul

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

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

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

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

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

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

That was me and it was a Pomy video I don't mind processed canned meat Paul

When a motor is rebuilt, generally I would remove as much from the cooling system as I can Leave the radiator cap off until operating temp is achieved and the thermostat opens Any air trapped in the motor is released, top the cooling system off, put the radiator cap on, take for a test drive and check everything is okay I reckon thats pretty standard across the world and open to correction if I'm wrong and missed a step Joey your right about cavitation, but what is it, we know the result of it But what causes it ? I had it explained to me many years ago in a way that made sense Were does this air come from ? Paul

This doesn't really explain were the air comes from once the air is expelled What is this tricky thing called cavitation ? What causes it ? And how can that is alledgedely trapped in a water pump be such a issue ? How doe's a centrifical pump work ? These are all things that have to be understood to understand how cavitation occurs and what is required to stop it Ask a irrigation farmer that relies on centrifical pumps about cavitation and it's effects on pump life and the pipe work connected to the pump I can tell you as a irrigation farmer, that water will not get stuck in the pump as your suggesting The moment a centrifical pump is primed and spinning that water is gone If it wasn't the the pump wouldn't be primed So keeping this in mind, assuming that bit of information I have suggested is correct Were does this pesky air come from that causes cavitation? I can assure you it isn't the injector sleeves And why do some makes of motors never suffer from this and others do all the time ? I'm trying not to be condescending here, we all learn things differently and I'm trying best to teach people here Cavitation isn't simple like people think Paul

John Deere sold plenty of industrial engines, lot of farm irrigation pumps and generators had/have John Deere engines Dunno about Mack, I'm thinking Kato cranes in Australia But I'm fairly sure they were a crane bolted to a Mack chassis Paul

WOW thats a lot of typing Anyway, lets keep it simple because Im a dumb ass If the air is expelled from the system, why does it have a pipe, going up fown, left, right or were ever to bleed trapped air away ? As once the air is expelled, there is no air left So whats the purpose of this pipe work ? Paul

Well I guess engine blocks and heads must be different in the southern hemisphere than in the Northern hemisphere as there are plenty of spots in castings were air can be trapped So keeping this polite and well mannered If air is simply trapped in the water pump as suggested, why do manufacturers put a little pipe or hose around the pump to the thermostat side ? Paul

Dunno if you blokes have scones in Yanky land or Devonshire tea's or any of that jazz anyway, when sausages are more flour than meat at a butchers, if we are been really cheeky we may ask for so many kg's of scones ha ha ha Paul

I could agree with Geoff, but we would be both wrong then The first thing people need to understand is what cavitation is It isn't just air in water Anyway I'm sure you'll have quotes and stories that will shoot me down in flames and I'm not getting into a I'm more right than you type of conversation We need to understand what cavitation is and what causes it and how a pump actually works and if air really got trapped that easily in coolant system then there would be bleeders all over the block and head and any little defect in the castings Anyway I'll leave you to think you're right as I'm only a dumb ass skippy the bush kangaroo from Australia ha ha ha Paul

Come to think of it, a Detroit water pump is down really low so plenty of atmospheric pressure to lift any air out Paul

Because Mack built motors properly Probably need a bleeder on a Cummins as Cummins were susceptible to cavitation Detroit (2 stroke) I have never heard of any cavitation issues IH was like Cummins and renowned for cavitation problems Paul

Floor boards ??? Hope the termites don't eat it 😯 Paul

A sausage sandwich has a very different meaning in Australia Let me just say, at the gay Madi gra you would be very popular eating sausage sandwich Paul

Again from the Rootes, wouldn't think many H model Macks on the Alcan hwy "North American Imp" Paul

Well I think hell has just frozen over, have had tofu twice now and it wasn't to bad, not as good as bacon or Spam but was okay and quite enjoyable I have become a very modern person Paul

It must be pretty big difference Even C models as I may call them, CH, CHR and so on used the R model chassis in Australia There has gotta be something special about the R model chassis I'm gunna say, without looking it up that Mack Australia stopped using the R model chassis maybe 10 - 15 years ago Paul

You are seeing this right This is a F model and they were only sold for a very short time before the F model cab was put on a R model chassis and from then on they became the FR The R model chassis was used well into the 2000's as it is suited to RHD trucks Paul