Vladislav

Looking your pics I dont see a reason you need new pistons. Cylinders relining is too probably on the way and suitable compression rings chosen by the size. When you recondition the liners you just bore new ones to get required gap to the existing pistons. There may be another way of ordering new custom made pistons already oversized to rebore the block. If you find yourself lucky finding a NOS set of oversized pistons and rings for them that's the most straight and correct way. Those flathead Mack engines were of multiple models and of different displacements. Yours is probably EN354 of 354 ci. But this point definitely needs determination since you should start from it in your search. Vlad

Would be cool if you point out where the truck is located and add a couple of pics to represent the look. Vlad

Honestly I would take the existing seals off their places and measure them and the mating parts. Than go to Stemco.com and find modern hub seals which suit your hubs. Speaking front axle my guess is you need 4"x5,131"x5/8 (or nearly) oil seal. My 1945 L-model Mack has these seals in the front axle and your truck is very similar. Mack part # from 1945 parts list is M-88AX-110. I had luck finding new seals of that size and later found out they were also used in a 1988 R-model axle. You may try to find cross reference to the numbers you have on the net but my experience was of no result with old Mack part numbers.

TRD-37 duplex tranny in my 1945 military Mack has compound stick at the right of the main one. And it has two positions - direct and over. With neutral in between. Over shifts backwards. Overall the tranny looks very close to a TRD-72 and its family and the main difference is inside concerning the 1st gear design. So I guess the compound stick at the right could have had common use in B-models at certain times.

I also see your post of much interest. Plenty of mechanical experience. Still haven't put that crank balancer of a wheel balansing stand. But found a guy who's ready to experiment (and has the stand). I'm not in a hurry on that since the engine is in pieces yet.

My guess is your truth is there. Actually I'm way far from being a firetruck expert. There's plenty of guys on the forum who know those matters better than palms of their hands. They just habitate the firetrucks section of the site the most as it seems to me.

I hope no one would blame me for use "his" picture in the post to explane the matter of question. All the pics were shared on the net at a certain time and many on here. I have some photos I made myself but those are large in size so I'd need time to copy and resize them to post in the thread. I point out once more that the trucks which don't have horizontal bars on the grill were the most probably firetrucks originally. Or just the grill was swapped. But many firetrucks also had special front bumper you can see on some conversions.

The truck you are looking the info on originally was a Type-75 firetruck which were built in late 30's and through 40's I belive. Could pull more accurate data from a subject-specific book if you need. Basically it was a E-model Mack cab and chassis. I'm not sure on the particular E model (they differed by multiple types regarding to weight ratings) but the most probably it used EH chassis. My guess the reason the model was not a E-something but Type-75 was the trucks were made by Mack as complete firetrucks already. So the model was established basing on the pump capacity as Mack did for firetrucks and not the way commercial chassis were named. Some amounts of those Type-75's were produced during the WW2 and supplied to USAF and also went overseas by Lend-Lease if I'm not wrong. If you look at the pics below the overall appearance of a EH-model and that Type-75 is about almost the same. But there's one (at least) special part which may point you that a truck was a firetruck when it left the factory - slightly different design of the grill. Commercial trucks had horizontal bars in it and firetrucks had plane net with just a framing around. Seems like many firetrucks were saved but lost their fire bodies at some point. Vlad

Funny. As the first thought it seems like the bleed from the relay was made to indicate the parking brakes were not applied But actually an interesting point to not worry about the relay's operation.

Ok, now it seems that all is clear. Sorry to stir the pot on a subject that had no direct relation to your original issues. But we better should use correct terminology to understand each other correctly. BTW the part # for that 6-pole junction block is 71MR403P6 and it crosses to PAI MJB-4385.

Thank you for improving my linguistic skills ones more, gentlemen! In this particular case I figured it worth better investigation (for me to learn the lesson essentially) so made a bit of Google search. I figured from there that buss bar (bus bar also looks correct) and a junction block are not almost the same matter. Definitely both are a bar with a line of terminals. But buss bar is a solid metal bar with multiple connectors. So my understanding is it's for connecting multiple wires to the same potential providing minimal resistance between the terminals. This way it can't be used to connect contacts of different circuits and seldom used in automotive products (and that's why I never met the term). A junction block has every terminal electrically insulated from the others so its function is different. Please correct me if I'm wrong since that's how I understood the subject but never used the term in practice before. My dad likes to joke that a person who tends to teach doesn't know the matter himself in many cases. And this time I'm just in a half of a step to be such the person

Keith, many thanks for detailed and systemized description of that reversing valve operation. I remember many talks on here concerning troubleshooting in the rack limiting setup. My running R has the system unhoocked and there's black smoke if you try accelerating a bit earlier on revs than you should. I could collect a few relay valves from different engine leftovers to play with but haven't started yet. One thing I did was opening one valve (by grinding off its body) in attempt to fabricate a new housing made of cooper or SS to look bright. But all I got to was a broken rubber diapragm found in the valve. So the quest is to be continued and the info above is going to be of much help.

I belive the truck Jim posted the pic of was property of Leslie Eversole who used to be a moderator on here a while back.

What bus that bus bar came from?? Sorry I'm not a native bus specialist

Paul, I'm generally with you on your statement (and many on here know that) but you forget the guys in the US has SNOW on many roads at the moment! Speaking old tyres if I worry about them I'd just buy a new set at the place the truck is for sale and swap then in locally before the trip. No matter where to buy tyres if you lean toward having a new set anyway.

Your truth it is. I forgot about that shoulder. And any (good) work should be payed up. You could accept his offer but doubtly would be able to make another job done there. And sure it wouldn't be honest. I had experience reconditioning working surface on 16.5" brake drums for Mack spoke hubs. Had to drive to the opposite side of the city (nearly 40km of traffic) to a shop with a lathe big enough. Good thing I asked (twice) on accurate centering the drums in the chuck when spoke by phone with a manager. A guy in the shop put first drum on the lathe (by the outside of the jaws since the hole was really large) and was going to cut. I asked for a dial gauge... He showed out big surprize and after I said I was promized the check he went to a shelf and picked up a stand with a gauge. All in all it took him nearly 30 minutes to center up each drum and then nearly 10 minutes or so to cut. Slow revs indeed. So he spent nearly 3 hours cutting 4 drums. And that cost me crazy money. Something US $40 apiece that time

If you looked inside and saw the big gear with teeth unbroken I think the main check was Ok My curiosity usually leads me to count them teeth and count out the ratio. But not much need in that if thinking global...

Belated congrats, Paul

My understanding is those shields were important when seals were not efficient enough. My 1945 Mack truck had hub seals made of leather. Modern stuff wouldn't allow any greas to go out if all was centered well during machining so my guess you will be Ok with what you've done.

For $300 I think you could cut the edge of the drum by an angle grinder. Half an hour or so to cut and 20 minutes to even up the edge. Being where I am I sure would bring drums to a machine shop. But I doubt it would cost more than US $30 for each drum to cut.

PAI supplys the headlight assembly and also in parts. Those plastic stands and screws avalible separately for a couple of coins.

It's also on ebay at the moment but looks like a very strange wheel to me. At least I have no idea on a model it could possibly be off.

No kidding Paul. I hope the borders will get open in a year or so and I'll be able to drive to Europe. So grabbing a can of spray and putting in a trunk would be rutine. I even could put it in a luggaje bag if resolve to shake up my bones a bit and go by motorbike.

Could be a E-model Mack. I have no clue on the shaft size but the wheel OD and the style makes the guess.

Great to hear about the boys! Time goes by and it looks like it goes the right way