T-Mack1

Our "1211" is an aerial and at lease one of the other Boston chassis' were too, so I believe the list is just B85F's and not limited to one type of use. A possibility is they may have been delayed or the orders canceled.

Thanks. I wonder where/when 1213 & 1217 were made..

There was a note in the Boston order paperwork for for fast shipment and one urgent.

minor correction. 1209, 1210 & 1211 delivery date should be "56" not "57". I did say it was hard to read..... LOL

Will do. I have been talking with my buddy who is most likely a genius that never went to college. Machinist, Top 50 GM mechanic at one time, and Electronic GURU. I had him look at all the options including using the more modern Leece Neville rectifiers (one Pos one Neg. ). His opinion, since the selenium rectifier has significant resistance forward, one of those 3-phase rectifier modules would be a big improvement. He said get one that is rate higher than the alternator output. 120A at a minimum, for our 100A ALT. Also said get the lowest voltage one you can get. So, after he looked at the spec's of one I found, we got a 800v 160A bridge rectifier module. I just have to build a heat sink for it. Again, working with him on size for it. He said that we should see slightly higher charging AMP's and at a slightly lower RPM. EDIT: the bolts on the module are M6-100 which is nearly equivalent to the 1/4-28 bolts used on the Selenium rectifier.

Next update. Thanks to the user posts here on Leece-Neville Alternator/Rectifier/Regulator systems, our truck has been converted from Positive ground to Negative ground. It was rather easy thanks to Leece-Neville alternators NOT using "case ground" methods. The rotor coils and also the output coils are isolated, and the regulator only maintains a voltage level and since the alternator make AC voltage (3-phase at that), the output of the regulator is not polarity sensitive. Only had to swap the rectifier output wires. Also had to also swap wires on the ammeters (A & B ) so it responds correctly. The water temp and Fuel gauges were bad and are disconnected. And since the starter is not a permanent magnet motor, it also is not polarity sensitive. Pictures: The rectifier before & after (note: we're upgrading away from Selenium). Notice the cloth on the thicker wires and you will see they are switched. And one of the alternator with labels added.

More updates. We have two air tanks and there appears to be a check valve between them. But, the air pressure gauge only had one of the two needles/lines/ports connected. So, I was able to find unused 1/4" air lines (I believe from a air valve at bottom/under the dash that is long gone) and there was a plugged port on a fitting between the tanks. And presto dual air gauge works.

DM800guy, We're looking for one. Message sent.

All, In the stuff we received from the Mack Museum, here a list of B85F's from 1200 to 1219, on a form called "CHASSIS REGISTER". It was handwritten and a little hard to read, so I typed it up and did a screen shot. Note: there are 3 chassis that were not on the list, 1203, 1217 & 1218. And for people in the future searching the internet to find their truck: B85F-1200 , B85F-1201 , B85F-1202 , B85F-1204 , B85F-1205 , B85F-1206 , B85F-1207 , B85F-1208 , B85F-1209 , B85F-1210 , B85F-1211 , B85F-1212 , B85F-1213 , B85F-1214 , B85F-1215 , B85F-1216 , B85F-1219

More Photo's. Fender inserts. They were missing so the seller provided them as they were not on truck when we made the offer, and were part of offer. Color is not a perfect match but looks better that the before picture.

More photo's of the project. Gauges. I cleaned up the bezels on the Air gauge, Speedo and Oil pressure. I inserted the Electrical tach (gas engine) in the hole where the water temp was only as a Photo-opt thing. And, we have a mechanical water temp gauge not shown in picture. The factory electrical water temp gauge was bad. The little fine return spring was rusted away. For the Speedo, I bent the crimped bezel open slowly, cleaned the metal, filled the pits with J-B weld quick, and painted and slowly bent it back. Also had to paint the inner black cover bezel. We are expecting the Fuel gauge to be bad since it uses a similar return spring as the water temp gauge.

Well hello neighbor. Emmaus & Bally.......

Yes!! We live in eastern PA and the convenience store chain WaWa carries Non-ethanol gas.

Great minds think the same. I just figured out the Youtube thing and edited them in. It wasn't too hard.

Here's an up date on my Brother and my B85F that was once part of Boston Fire Dept. It lives, moves and stops!!!! Sunday 3/9/2025, Jack and I got it running on a temp gas tank and got it to move around. Videos are my brother Jack driving. Note, I boobie-trapped him by having the auxiliary shift lever in neutral. He figured it out. And, even though he has been driving manual trans cars for over 50 years, he never driven a truck with non-scynornized trans before. Truck-wise, it builds air pressure to normal levels and the compressor kicks on and off where it should. The battery charges. Oil pressure is good. And clutch seems normal for the 2 times we drove it up & down his 700 foot driveway. On Facebook: https://www.facebook.com/100009041979074/videos/538239552636001 https://www.facebook.com/100009041979074/videos/619931730934531 On YouTube.: Part 1 and below Part 2 Part 2:

In the last 14 years, I don't remember seeing any spoke wheels, and definitely in the last 7, while I was in the Quality Group, I can say have not seen any spoke wheels on any trucks at the Macungie assembly plant. Some strange big ass planetary hubs and associated big wheels, but no spokes.

24" is still made as a Euro spec tire. Last year Mack Trucks had a customer ordered trucks with a ultra duty axle that was imported from Volvo Europe and the only wheel available that fit the hub was a 24". BUT..... when I did the Quality Audit on the truck, I didn't look to see if it was tube type or not. Sorry. What stood out was the customer ordered White wheels and they only could get gray rims. The factory doesn't repaint the rims, so a Quality gig.

Yea, this thread was drifting off the RPM limiter and carb question. But, it help me understand that having a login only means you can do threads, and have a limited amount of attachments. So, I paid for the lifetime account and now, watch out........ pictures will be coming. Why...... because I figured out how the limiter on the EN707C (ENF707C??) works and took pictures. Plan to post pictures and if size allows short video so others understand too.

Was looking at those. Would need regular polarity and reverse polarity diodes ( stud anode and stud cathode). 2 each for single phase (4), and 3 each for 3-phase (6), and would have to isolate the plates the studs are mounted too.

Or these https://www.ebay.com/itm/114601767481 (2 for single phase, 3 for 3-phase.) mounted on a heat sink. 100 amps / 800v EDIT: Pin one = inputs, pin 2 is Neg and if modules are mounted side by side, could use bus-bar to tie them together, and same with POS pin 3.

Figured out where the regulator was, thanks to a post in 2023 that Geoff was helping Angelo. Saw the picture of Angelo's 7v unit and we have a similar Leece Neville 14v box on the inner driver's side firewall. Yet another thing to trace wires to-from. And, yes I know we need to get up close and personal to the alternator to figure out the output leads. If you look at the picture of our system (below), you can see the smaller wire going to the alternator, so I assume one of them is the field. You can't see that there is another small one on there too. Plan is to see if the truck runs first. Which means my task next is double check ignition. I have new parts from Brillman just to see if it runs without funny noises. Then go electronic. More crawling around...... Lots to look at .... as I sit here watching it snow. We most likely will convert to modern rectifier. May actually use my Assoc. Degree in electronics and make one on a large heatsink. But, also leave the old one there just for looks.

A friend of mine asked off-line if it could be a Dual-Charge system. In other words, a redundant system to charge Battery A and Battery B separately. We do have two Ammeters and the battery A / Battery B switch on the dash.. Did they do that on some of the fire trucks????

The Leece Neville ALT (100 amp) has 4 leads coming out. (maybe 3-phase plus a ground??) The tag on the ALT has "Rectified" and "Rotation reversible". I would post a pict but I didn't realize I had to be careful on size and used up my limit.

Selenium rectifier like my son's old Honda SL70. Only issue was Honda used the battery to absorb the voltage spikes at high rev's and that would boil the battery water/acid away. Cheap regulator. Only issue was if the water was gone, you would send 18 volts to the 6v light bulbs. Our ALT is 100A per the build info. On the tag on it, it says Rectified, so I was thinking it was internally rectified and externally regulated. Also, when we checked for POS or NEG ground, hooking up the battery as NEG grd, had a big current draw. Swapped leads to POS grd and everything was normal. I was thinking it was a Alt/rectifier/regulator issue. Now I'm going to have to think a bit..... it's only been 40 years since my electronics training..... Mind like a steel trap.... very rusty.

Messaged you a picture of the square finned thing.