Full Floater

Seems as most older Macks use a 10psi 2-5/8'' neck rad cap. Has anyone ever put a lower psi rad cap on, for reduced strain on old cooling systems? Or even a 0 pressure cap. I have done this on SEVERAL old vehicles including diesels (wet sleeved and parent bored) and have never had any negative results and very few cooling system related issues and no blow outs of things like hoses and heater cores and such....which is what im concerned about. Yes, I realize that lowering the psi also lowers the boiling point of the coolant, which is fine by me as I drive with 1 eye on the gauges and never let it get anywhere close to hot. Any thoughts? Cavitation? Hot spots? Thanks

Ok thanks, ya im just trying to adjust for wear.

Stupid question, but these can remain all together (not separating the ball joint) for adjustment, right?

So....the sticker on my factory heater blower motor says to use the cowl vent for ram air heating. When I have the cowl vent open (there are no obstructions in it that I can see) I have very little ram air effect coming in even at highway speeds, so I end up having to use the fan anyways. Am I missing something here in the cowl operation? Is it normally as effective as the sticker makes it out to be? Would be nice to have ram air instead of using the fan. Thanks

I would assume.

I have a Borgwarner 4LE-292 Turbo on a stock and stock fueled 237. The impeller has a few chunks missing out of it and i'd like to replace the turbo instead of just the compressor wheel, as it's probably due anyways. I know this topic has probably been beat to death, but is there a current "better" option out there for bolt on turbos? I don't want to alter any piping or anything, nor do I want to increase the fueling rate. And im not looking to make more power. Just curious if there is something out there that modern technology has refined, made more efficient etc..., that would be worth looking at. Reliability and longevity are key....but if we can reduce exhaust smoke a bit and maybe squeeze half a mile per gallon out of it, that would be swell. One thing of note that im finding as I internet search the 4LE-292 turbos. It gets listed as a turbo for a 285, opposed for a 237 which comes up as a 4LE-303. Any insight on this?

You know it! And they never admit it!

As of today, another R model has been saved and put back on the road for another few decades of service hopefully. This truck was left for dead, then acquired and converted from a tandem dump to a s/a rollback, with parts from other R's left for dead, and much help and advice along the way from the fine folks here on BMT. This truck will join a small fleet of other old iron, running 24/7 on call service, year round. Through all the weather and in a challenging geographical area. Thanks guys. The next Mack will be a lowbed tractor.....

Thank you

Getting to learn a 107 series rear mount pto at the moment. With the aux box in N, the pto still spins with the main box in N, OR in gear. Is that normal? And just to clarify what most probably view as obvious, is the pto supposed to spin faster/higher rpm when the main box is engaged in a higher gear? Is there a downside or anything to watch for if the main box is in a higher gear like 3rd or 4th? So far i've only been experimenting with 1st and 2nd but wanted to be sure its ok to choose a higher ratio

Good tip! Just tried mine. She's seized.....on to the penetrating oil...

Thank you! So spin in the cap with a larger flathead/straight edge of some sort I would imagine?

Is this the style we're talking about? JoeH, if so....how does one adjust it?

In applications where there is not enough room to swing a hammer or something to drive an old pin out, I can see the threaded pins coming out ahead in the serviceability standpoint

Got them done! Went smoother then I expected. Thanks guys. They should be good for another 50 years now.

Does it do them any good, to disconnect the air supply line to them and give em a squirt of some form of oil from time to time?

Excellent advice. Thank you

Nice, that's good news. Ah ok, didn't realize the shackles have to come off also. But that makes sense. Thanks fellas

About to install these sassy new front springs in my 75 R model. I have never messed with Mack front springs before, and im curious about these threaded spring pins. What is the best method to remove them? Is there to tool to fit over the slot or can I put a wrench on it to spin them? Also, what are the pros and cons of threaded pins? Many thanks

Take the switch apart or the motor? Id like to dig into the motor (which works fine) to clean it up and make sure its good for a while.

Interesting....is that a Mack thing or just specific to the CL series? I have a couple R models that have a little slop there.

Thank you guys. I just ordered that one from HD pros. We'll see how she goes!

I'm new to the air wiper world, or at least; new to servicing them. Never really had much trouble with them before. The air wiper switch on this 75 R600 is leaking air in the OFF position. What is my best way of resolving this? Is there an o ring or a kit or something that I can replace? And as for the air motor itself, although it works fine, it's probably never been touched in 48 years, is there anything I should do to it in regards to maintenance? Cleaning? oiling? Many thanks!

That seems to make the most sense, doesn't it.

Re-visiting this topic. Im now at the heater box, putting together 1 heater box out of two. Same boxes, same dimensions, different heater cores. One appears to be a 3 row and much bigger. I'm assuming this one would give off more heat? Your thoughts?