MorrisMe

I know this is an older post but can anyone help point me in the direction of where the bleeder valve is located?

I cannot find it anywhere protruding from the unit in the truck.  do I need to disassemble the unit to get to the bleeder?

Mine were both Positive ground.

How did I know? Since they came that way, I checked the diameter of the cable post, and they fit positive post to the grounded cable, negative post diameter fit the starter side cable, so I knew that was how the last battery was installed.

Not really sure there is any advantage to switching it over unless a guy was determined and really wanted to go to all the trouble.  Maybe I would do it if I was going to install lots of modern electronics.

On 3/4/2023 at 4:40 PM, BOB DINGSDALE said:

MorrisMe: When you contacted Seattle FD did you get the truck number for each serial number . I have pictures off ebay of three of Seattle's units and one that was in bone yard in SPANWAY WA. Would like to get chassis numbers of the 3 off ebay and truck number of the one in SPANEAY to go with chassis number I haver. If you have this info could you email it to me .

yes I did, I will be happy to email this info to you.

18 hours ago, 70mackMB said:

MorrisMe, l know you found the trucks kind of in the woods. Where all the water inlets & outlets closed off and capped? Just thinking of them damn tree rodents and mice might have filled everything with acorns and pine needles. Can you run water thru the trucks pump system without using the pump to rinse it out?   .....Hippy

So you are correct, and that is what has me the most concerned.  No the water inlet / outlets on the side of the truck were not covered, however they do have the Grates / screens over the main inlets.  the tank was covered, and the drains are all open, so I really do not know what is in there.  I didn't want to turn it without knowing whats inside.  Flushing water through there may be a good idea, but it may also push crap into the pump, I was hoping that there was am inspection cover that would let me get a better feel for what I am dealing with.

I do have a long bore scope that I will fish into the inlet and see what I can see.

Recently picked up this truck and would like to see if the pump is working, but I don't want to turn it without knowing about it or what to do to test and try it before turning it.

any suggestions would be good.  It has the 1500 pump.

Water drain is removed, and everything looks good from the outside, just not sure about the internals and where to begin.

Yeah it definitely has the bass, you can just feel it hitting on each cylinder. 

No need for throttle when moving around, plenty of torque.

Excellent, Nice truck!

Thanks for the picture, That is it.

Well number two is also up and running, although after about two minutes of running I blew a oil line.  My son did take a "startup video" of it and when he gets it finished I will post it.

Ran beautiful and smooth once it got fuel.

Anyone know which Dog emblem I need to buy to fit the hood?  I purchased some B-Model dog emblems for the hood but they are too small and angled up, the hood outline of the Dogs are standing flat and about 2" bigger.

I agree with all the above as well, and since you rebuilt the engine that would eliminate your block and heads being plugged up (provided the block and heads were hot tanked).  Exhaust valves should have been replaced / reground, and new exhaust gaskets ect, (example: running with a bad exhaust valve could cause burnt piston).  Sounds like you have addressed all of this.  So...

Too lean fuel mixture = hot combustion.  Factory carburetor, are you sure this is the right carb?

retarded timing = hot exhaust valve and manifold.

Combination of both = extra heat.

only other thing could be head gasket.  I am not familiar with this engine but is it possible that the head gasket is on backwards or upside down, not allowing sufficient / improper cooling in the head?

Stock from the factory engine and carburetor should all perform correctly and drilling jets / pulling choke would only be a bandaid for actual problem in most books not actually fixing the real issue.  If the carburetor was at it's maximum flow capability from the factory then a .040 overbore could be overtaxing your fuel delivery. (requiring jetting and usually air flow as well.

check fuel pump pressure, all factory fuel lines / filters, to make sure fuel is being supplied in the correct amount.

9 hours ago, Mark T said:

Is that second truck Hall Scott powered too ?

Yes it is 1091 in both.  This one actually came with some extra parts as well. great to find.

engine turns over but the starter is not engaging, so I get to start there with this one.

Found a bunch of new / rebuilt / spare parts for this under the seat, great treasure hunt lol.

Also discovered that the Mack Dogs for the sides of the hood are much larger that the standard B model Mack dogs?

I found a new old stock set of hood "Dogs" for a model B,  but they are way to small to fit the hood.  Does anyone know where I can find the correct emblems?  Are they specific to the B-21 or did they come on other trucks as well?  I would guess that they are about 2" bigger then the ones I received.

4 hours ago, Brocky said:

If the Mack Museum is back in business after the Covid $h!t they can provide you with the complete build sheet and a lot of other info.. They are non-profit so it helps to send a donation with your info request.

I have try'ed them but they are not on line?

Any Ideas on which transmission and rear axle this came with or how to identify?

Yes, I will post some pics as well.

Nice looking Barn find, enjoy.