Geoff Weeks

I was expecting a FC which I think they did put a 5th wheel on one variant.

Are the rears Mack (Top loaders, center section bolt in from the top, or front loaders, bolt in from the front)?

Well, I took that info and went to a junkyard when I was doing my swap. Eaton and Rockwell (Meritor) used common wheel end parts so the bearing and seals as well as bearing spacing were the same. I know Spicer (IHC) use different bearings and spacing on their 12K steers. I have no idea what Mack uses. A junkyard is likely a better place to go than the dealer and new parts. They often know interchange info. In my case hubs off a Ford would work if I changed the outer bearing. In my case the rear axle were common 40K Eaton and IHC's which all take the same stuff as Rockwells also at the 40K level. What rears do you have? What front (steer axle) do you have. Hub Pilot came into being ten years after your truck was made, if the axle models were still in use in the 1990's then you have a good chance that the hubs are available. Many of the Mack's I worked on had heavy front axles, so 5x 16.5 or larger brakes, and heavier bearings than the 12K axles on my tractors.

Info that is going to be helpful is inner cone # outer cone # seal number, brake size. Axle capacity if you know it. That is all I used when changing from stud pilot to spoke.

Wiki has a pretty good definition.

In OTR trucking in this country the weight would be a problem. In buses you likely wouldn't have a problem with an extra 700 lbs, firetruck not a problem, garbage packer maybe or maybe not. I guess that is why they weren't a big seller here. In a country where far too many drivers look a a jake as a noise maker to startle people, they would have no attraction. Your likely looking at a similar weight penalty with a Cat brakesaver, and they were never very big sellers either. With the fact the engine can be ordered OEM with the brakesaver likely made them an easier sell then the Telma which would be a separate sale.

The ones (Telmas) I was around were on LP fueled M.A.N.'s so had a throttle and therefore would not work with a Jake. However if you could justify the weight there is no reason they couldn't be used with an engine Jake as well. Some of the heavy hauler had 3406's with both Jake and Brakesaver, as weight is never an issue when every load is a permit load. I don't know how much they weighed, but there was big rotor on the output (transmission) or input (rear axle) and a stator that surrounds the rotor with a series of electro-magnets in it. So lots of copper and iron. Brakesaver used engine oil to act on a turbine wheel between the engine and clutch. Retarding energy was turned into heat in the engine oil. Cats with Brakesavers have bigger oil coolers then those without. When Cat used an injection pump and nozzles in the head, there wasn't a handy injector rocker to time the Jake like there was with Cummins and 2 stroke Detroits for optimal valve opening. Cat Jake's of that period used an adjacent cyl exhaust rocker to trip the Jake, but its timing wasn't ideal so the retarding wasn't as good as it is with common rail engines. So that is why the Brakesaver hung around until the changes over to common rail fueling. At that point the timing came from the injector rocker, like Cummins. By the time we got the LP buses, mostly the Telam's didn't work, we had enough to do to keep the buses running and Telma's weren't needed in Chicago like they were in Austria where the buses came from. I think may be 1 out of 4 or so worked. Likely needed something simple, but there was never time.

Telma's were more often found on buses. 1) they are silent, so not to alarm passengers, 2) they are heavy. Buses usually have less trouble keeping on the good side of weight law. 3) they are electric and can suffer from the gremlins common to high current electrical devices. Cats "Brake saver" was hyd with engine oil being the medium used. It was heavy when compared to a Jake or Macks retarder. The reason for it went away when Cat (and others) changed to common-rail injection.

Not anchored to footings?

Closing off the back end will help as well as keeping debris from blow in. Cables in an X with turnbuckles to tension will do a good job as well. Closed back end with X cables would be the best.

Another thing to consider, if it did push significant amount of coolant through the air drier, then a complete service of the air drier is warranted. You said you drained the air tanks, was any antifreeze found when they were drained?

It sounds like a blown compressor head gasket. One thing that can cause that is a coked up discharge line between the compressor and the air drier. Make sure to check and see how well air can blow through that line so you don't blow the head gasket on the new compressor. When you have the compressor off, disconnect the line from the compressor at the air drier and use an air gun to blow through. It should blow with almost no resistance to air flow.

Honest, and you can sleep well at night if he still goes forward with the purchase.

I would say in the country, there are a whole lot more people who are center left, that don't like what they are seeing and not "left wing". There are extremest on both side of center, and being on "the other side" doesn't make you an extremest. Too often its "if you don't agree 110% you are the "other side' at 110%, and that just isn't true.

The problem is Jo-Jo already has an old IHC gas job. The big gassers are hard to justify to just take to shows. Nice, yes but expensive to insure, feed and register. His K-7 on the other hand, is of a size that you could actually used it for the occasional parts run or something. I have had a gas Fleetstar for a while before I parted it out. Only thing it got used for was a yard goat, spinning trailers around. My K-7 has done much more. I'm not knocking the truck at all, just that few can afford the luxury of a show queen that only goes to shows, takes up a lot of room, and the case of a 549 is expensive to run. Smaller antique truck can give about the same thrill and is easier on the wallet. It likely why so few of the bigger one survive. Other dog found it didn't fit him all that well either. There is a guy on another site that has one as a grain/farm truck. A little more options there to put it to use.