Rob

I got a call from a friend that has a mechanical E7-400 I can have cheap, (his term). Came out of a CH model one of his drivers upset with a dump trailer. It is said to run but the truck was too old to repair so it was junked. Will this fit into a B model or is it much larger physically? Never seen one out of a truck myself, and it's been awhile since I've seen one at all. Rob

I've seen all their stuff and it is really nice. The E7-427 powered B model is a really neat truck as is the orange F model. Both fit well in their collection. I'd really like to have a Hendrickson Brad has but too many projects now to tackle another. I'm still working on my uncle to get that one as he was a Chicago steel hauler in the late 60's, early 70's and ran one similar. Eventually I'd like to have a 79-82 Superliner, (I like round headlamps). I have an "extra" 1693TA Caterpillar engine I'd like to install into something someday. Also have a few V8 Mack engines to do the same with although none are the E9 series. Rob

Herb is correct. Those are heavy rears. You can tell by the type of trunion stand, and axle caps that are tapered. The axle shafts are actually two piece units that you can't see. I'd be interested to see the spring brake chamber mounting arrangement if you could post a photo of the area(s). On the rear rear housing looking at the rear of the truck, just to the rt. side of centerline of the housing bowl, there is a number such as SWD58XXXX stamped, (the X's will be numbers) and these will be the suspension numbers. Anyone with a book can decode these for you. I don't remember what year you said your truck was but the trunion stand shown is the same as the ones in my 63, and 64 year model B series trucks. These also have the piston type brake cans as Herb mentioned. Rotochambers actually have the rear of the can, (nearest the air inlet fitting) "necked" down about an inch total where the piston type do not. Wagner supplied most of the piston type, with combination of both Wagner, and Bendix-Westinghouse supplying the rotochambers. I've also seen a combination of both installed on the same truck however I doubt they were original to the truck in that fashion. Rob

There was a very interested party in the white one when I was there. I like the B, and R700 series trucks and was not really interested in a newer cabover myself, (although I would like a H-61, or H-63 at some time). The magnum cabover was very nice for it's age and had I been looking for something like that, it would have come home. I didn't see it run cause we didn't really want to smoke up the building. Sounds like you will enjoy it for what it is and appreciate it. Good luck in your quest. Rob

I looked at the truck at his father's new barn/building while it was still warm, so last fall. Both MH's were next to one another. Rob

Think I'd seen both of them. How long have you had the truck? Rob

Very nice straight shooting guy. I certainly wouldn't be afraid to purchase anything from him, or family. I looked at the truck when I was up there, it will be a nice project. Rob

The link posted is for a pancake type service brake chamber. These would work as acceptable replacements for the existing rotochambers but like I'm doing with my B67, go with 24/24 spring brake service chambers so you will have something better than the driveshaft brake drum holding the truck. However if the original driveshaft brake serves you fine the service chambers will be an easy swap. If your truck has heavier than 38,000# rears the 24/24 chambers will not fit without modifications to the mount(s) due to clearance issues. Rob

Pretty nice truck if that is it. Rob

Your description sounds like rotochambers. If your truck is a tandem of the vintage you mention, it would have been factory equipt with rotochambers. Wagner, or Wagner-Lockheed was the main supplier for rotochambers. Post a photo and we, or I can tell you for sure. Also rotochambers of the size used on trucks use a single air line plumbed directly into the center of the chamber at the rear opposite the yoke that attaches to the brake cam. Pancake type diaphram brakes have the air inlet at the side of the cannister that is behind the pancake or diaphram. Rob

If you have a manual priming pump does it feel as if there is resistance, or like your compressing air? Both of your filters should remain full when the engine is shut down. If they are draining back you could have the check valve inoperable, or an air leak in the system. Do you notice any seepage leaks from fuel anywhere? Rob

If those rotochambers leak at all, they are unsafe and need replaced. I wouldn't recommend you learn a very expensive lesson of procrastination here. If that truck will move, it needs to stop 100% of it's capacity, without margin. Rob

Most likely you have roto chambers as they are original and very expensive to work with these days. Just the diaphrams are over $50.00 each anymore and it sounds like you have one blown. Replacing the unit complete is about $300.00 or so. Most of the original sizing was for a type 20 diaphram so a type 24 will work well. I would replace all of them with type 24 spring brake chambers if you have either 34, or 38,000 rears. They will fit without much problem, (just bolt on and replumb). Of course you may be able to find a used rotochamber also should you want to go that route. Rob

I like dirt track racing at the county fairs around here still. Usually the driver, or his friends and family build the cars. That is what I call competition. Not this mass marketed garbage passed off nowadays. Rob

I've looked at, and drove that truck with the owner, (not the seller). He would not budge from $7500.00 or I'd have had it. That one with some routine maintenance performed is ready to work. Everything was working. The guy has owned it for over 25 years and used to work it, but has retired a few years ago. I'd be willing to bet that one will still work when the new ones are going for parts. It was listed on ebay a couple of times also. The 3406B with updated timing gearsets and upped in fuel delivery and timing altering is one hell of a dependable engine. I have several friends with that setup and they pull new equipment out of Cat with them nearly every day. Rob

Seen this visor on ebay for an R model series. Buy it now price is steep cause they can still be purchased new. http://cgi.ebay.com/ebaymotors/SUNVISOR-for-MACK-Trucks-R-U-DM-Models_W0QQcmdZViewItemQQhashZitem2a05aa2964QQitemZ180483664228QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories Rob

This is true, however my experience is that if you don't replace it at the first sign or trouble, (as presented), it will happen again. Not a real self healing type of unit. Rob

My guess is that if it has more than one tooth on top, and two on the bottom, (like me) I'll never understand either. Rob

Damn. I skinned my belly and now it hurts. Will you kiss it and make it well? Rob

Generic. Ask for a Bendix D2 style governor. Easy to plumb if different from your original and about $12.50 plus shipping on ebay regularly. I've purchased several over the years. Here is a good, honest vendor to deal with. http://cgi.ebay.com/...VehicleQ5fParts Rob

Sounds like the air governor has gone bad. Rob

I think 1985 was the last year for the tan interior. Both of my 1986 cabs have the gray interior. Rob

Yes it was. Jim had posted a link to it on the 28th of December using the same photo which is now gone from AutoTrader.ca. http://www.bigmacktrucks.com/index.php?showtopic=6422&st=60 Rob

That is the only way you will get it off of there if it is the original style. It can take quite a bit of downward, and twisting force to get them loose at times. The rubber slots the fingers slide into tend to soften and glue themselves together. Brute force can be resorted to also. As a last ditch resort, pour the center of the steering wheel full of denatured alcohol as it will soften the rubber bond but will send you howling for help if you have any cuts. As a final solution; Sears sells a BFH that will take is off of there. Rob

Get a piece of inner tube and ensure it is clean and oil free. Cut it to the diameter of the horn button, place it on the button, then push down with the ball of your hand and turn. Sometimes they are stuck from being in the same place for so long. Unless it has been glued down, (I've seen that) it will come off of there. Rob