Major Rob,

I have another question for you regarding M939 trucks. Italeri model has simplified suspension and among other parts missing does not have brake pumps attached to the wheels. From various pictures I 've found I was able to find out that there are two pumps (or pump like devices ) attached to each of the wheels on rear axes, like on this picture in your gallery: https://armorama.kitmaker.net/modules.php?set_albumName=albus36&id=aar&op=modload&name=gallery&file=index&include=view_photo.php. Picture shows wheel on the second axis, wheel on the first rear axis has pumps switched - so two smaller pumps are between rear axes.

I have CMK resin wheels set for M939 and there are resin pumps added to the set, but there are four bigger pumps and just two smaler pumps. CMK instructions suggest that smaller pumps should be installed to front axis of the truck, and shows only bigger pumps attached to both rear axes. I also have resin detail set for M939 from Real Models - there are also two small and four bigger pumps in the set, but no placement instruction whatsoever

My question is, are there really any such pumps attached to front wheels? I coudn't find any good picture of the front axis area, that would show steering shafts (also missing from Italeri kit) and other parts of front suspension. On some pictures I have, I can't see any pumps there, but these pictures are not clear.

Could you take a look at front axis of any of M939 family trucks you have in your motor pool and tell me if you see any brake pumps there similar to those on rear axes? Of course it could be great if you could take some pictures. I guess that you may also have some technical manuals for these trucks - I would expect that there are some drawings of front suspension there. So insted of photos, some scans of drawings could be also useful.

Thanks in advance!

Best Regards,
Pawel

Marcel,

I'll take some pictures this afternoon and post them on my web page:
http://www.vodnik.republika.pl.
You may want to visit my webpage now and take a look at REVIEWS section - there is a comparison of CMK and CAM wheel sets for M939 trucks.

Regards,
Pawel

I just went out and took a look and talked with my instructor for that vehicle. There is a large "pump" and small "pump" on each wheel. That means four of each. I didn't bring my camera today, but will take photos tomorrow, weather dependent.

The items in question are part of the service and emergency brake system. The large ones are a combination service/emergency brake and the small ones are service brake chambers. The smaller ones mount inside the dual axles and the large ones outside of the duals. Basically they mirror image one another. I'm only talking about the four rear set of tires and not the two front (steering) wheels.

Sabot,

Thanks for the information. At least I know what these pumps are. You wrote that you meant only rear set of wheels, does it mean that there are no such pumps on front steering wheels? Front axis area is uncharted territory for me - pictures in your gallery don't show what is hidden directly behind front wheels (although some fellow modeller has just send me links to Technical Manuals for M939 series of trucks, so I may be able to find out more myself soon!).

Rgds,
Pawel

Marcel,

I have never seen MR wheels, except for the picture you posted, so I can't comment how they compare to CMK and CAM. Tires on A1 set look nice - it seems to be Goodyear pattern, but rims of front wheels look strange - they are not quite correct. As for A2 set, this is obviously the wrong picture - these are wheels for some other vehicle!

I took some pictures of Real Models set this morning and will post them on my web page in Reviews section in a couple of hours.

UPDATE: picture and small review of this set are already on my web page. Go to http://www.vodnik.republika.pl and then select Reviews form the menu.

Rgds,
Pawel

I found a pair of axles still on the shipping mounts. I took photos of them and will upload them as soon as I resize them. Great detail shots of the backside of the wheel. There was both a front and a rear axle. On the photos, you will notice that the smaller service brake chambers are present on the front axle (the axle with the tie rod on it).

The rear axle has four of the larger service/emergency brake chambers pre-mounted on it. I do not know if these are 5 ton axles or HEMTT axles, but they should give you a good indication of how the brake chambers mount to the wheel.

Major Rob,

Thanks a lot once again! I checked some pictures of HEMTT and these axes look different, so I guess they are indeed for M939. Strange that there are two larger chambers on each side of rear axis - other pictures I saw show always one large and one small there.

As I mentioned earlier I now have the Technical Manuals for M939 trucks, and these are really great source of information for modeler! With them some serious superdetailing is possible. For example I just found drawings and placement diagrams for all decals and placards present on the real truck! Most important is that I found detailed drawings of all suspension parts, so I know what I need to add to my model.

Still your pictures are very helpful, as it is always good to see actual photograph, not only drawings!

Regards,
Pawel

I added a couple of axle shots from the M931A2, they may help a little.