rhasler

Maybe they're afraid it would make too much sense to own a whole market segment.

On your engine the engine brake is supplied power through the engine ecu. There is a disable relay for the ABS system but that doesn't sound like the probelm. I would look at the solenoids personally, especially if nothing has been done with the Jakes/valve adjustment lately. If you haven't done anything with the Jake you may want to install the Jake overhaul kit. Jake suggests the brake be rebuilt at 150,000 miles. The overhaul kit p# 4559-31180 updates the Jake to current revision level and includes reset screws, springs, control valves, most of the snap rings, and solenoid o-rings. The exhaust valve yoke adjusting screws need to be checked for wear. If the screws measure less than .960" inches they ALL need to be replaced with current part number 421GC41CM. Installing the overhaul kit requires a slave lash setting change from .015" to .021". Most of these changes were implemented to prevent breaking of the valve yoke guide pins and subsequent valve dropping issues.

The engine brake solenoids are located under the valve covers. They sometimes quit working properly. Did this just crop up or have they been acting erratically since new? There is an update kit available through Mack Partswhich corrects some weak brake and other problems associated with your model Jake Brake. I will look for the service bulletin later and let you know .

Rob, you are a magnanimous and wonderful person.

Regarding stopping distance-you're probably right. Regarding compatible axles-Bendix air disc are available on 12,000 front and 40,000 rear supplier axles as of now. I wonder if they will be available on the Mack FXL axles, as these, I believe, are manufactued by Meritor. Mack has also recently changed the standard production brake from Meritor Q Plus to the Bendix ES. One thing I've learned from working on Mack MP engines is that global supply of parts doesn't neccessarily mean local availability.

My tune up specs for 1984 don't show an E6 300 engine with series charge air cooling. I'm guessing the original engine was replaced in 1984 and the engine components from the original were put on the ReMack engine. Judging by the other engines in the book I would guess boost should be between 19-27 psi

Engine Model Designations Engine Model Designations.pdf Engine Model Designations.pdf Engine Model Designations.pdf Author rhasler Category Antique & Classic Mack Info Submitted 06/07/2010 08:19 PM

Here are the model designations for pre 1980 engines, sorry about the quality of the scan. I'll load it to the wiki as well. Engine Model Designations.pdf

Check the steer axle tires for feathering. This is an indication of possible tie rod end/toe setting problems. Wear on the tires generally appears as no or almost no tread on one edge of the tire, and slightly increasing tread, in a staggered pattern, to the opposite edge. A tire worn on one edge as stated above but without the feathering is generally a camber problem and is most often kingpins or wheel bearing. Mack has specific guidleines for checking kingpins for acceptable play but they are much too technical to get into if you're just going to check it out.

It's under the wiki tab at the top of the screen. Click wiki, click antique and classic Mack truck articles, click antique and classic Mack info. It should be the last entry on the first page.

So is the problem high coolant temperature or is it high pyrometer temperature? I'll see if I can find the specs. for boost tomorrow.

Here's a link to the Bendix Quick Reference Guide. Air dryers are in section 08. http://www.bendix.com/en-us/service/library/Pages/Home.aspx Hopefully you can identify it by comparing to the one on your truck.

There are several different models available in a couple of brands (Bendix and Meritor/Wabco). Without actually looking it up by chassis record theres no way to know what it was built with. The Bendix AD-9 is a popular model, but the cartridge is not a spin on. It is mounted inside of the air dryer assembly. This may be what you have since the mechanic says there is no cartridge. There are rebuild kits available for them as well as exchange units. I'm unsure of the cost of the rebuild kit compared to the exchange unit. By the way, don't go cheap on this. Make sure to buy whatever you get from a reputable source, there are all kinds of counterfit air dryers out there. There have been cases of air dryer cartridges filled with cat liiter instead of dessicant material. You may be able to identify your air dryer yourself by visiting the Bendix website & looking at their quick reference guide.

If you can't find the post this is probably the information you're looking for: SB637021 Date: 08/31/05 Model: CX, CH, CXN, CHN (Also applies to Mack Trucks Australia) Sleeper Air Conditioner Evaporator Freezing and Icing — CXN, CHN, CX and CH Models with Blend Air-Type HVAC System If sleeper air conditioner evaporator freezing and icing up complaints are encountered on CXN, CHN, CX and CH model chassis equipped with the blend air-type HVAC system, a service replacement front (cab) expansion valve (part No. 4379-RD570151) is available through the MACK Parts System. Replacing the cab expansion valve (front unit) located on the cab bulkhead will correct the ice-up condition of the rear sleeper unit. Expansion valve part No. 4379-RD570150 is not applicable for this repair. Be sure to use the service replacement part No. 4379-RD570151. Hope it helps

Thanks. I'm always wary of new products, especially when there is a lot of "information" available for them. Usually it seems to be mostly sales literature, but Bendix is pretty good about the information they put out and their products are generally pretty bulletproof (assuming they weren't counterfit products and that they are installed correctly). They wouldn't be making the majority of brake valve products, etc. if they didn't build quality products. With all new products it's not what they tell you that's important, it's what they leave out that is. Guess I'm just sceptical when someone tells me I should upgrade from a system that suits my needs without any problems to something pretty unproven at substantial cost to me.

It looks to be, and all production to boot. This only shows the information Mack is aware of (ie if you swap parts with something from a wrecking yard and don't have a dealership reprogram the new ecu that info won't show up). If you are the original owner and know that nothing has been replaced then what I'm looking at says everything is the same as when it left the factory. You do show to have compatible software (Step 7A) for the file mentioned earlier. The engine, if rebuilt/replaced with New Mack parts, requires a low Nox datafile be installed. Not installing the file when required results in severe financial penalties to the person doing the work and maybe to the owner, I'm not sure on that one. Also, I am unaware of how these are enforced in Canada. Remember that these files don't solve all problems, and certainly not existing mechanical problems.

There may also be one for Gambi80. PM me the serial on your truck and I'll look to see what step its supposed to have. Depending on if the engine has been rebuilt, if certain components inside the engine have been replaced, or if the engine has been replaced with a ReMack engine, the datafile may be a "Low Nox" file. This is federal EPA stuff and if this is the case I don't think Mack will change it to something else. This applies to the VMAC I, II, and III chassis with certain serial numbers

I checked my information. There are actually different files. One for highway chassis & one for vocational chassis. It is DSM enabled. I was partially incorrect earlier. The file is actually to correct the problem at light load and ambient temperature of 80 degrees. Now that I think about it there was a CH613 that came into the shop shortly after the RD688S with the same problem and thats how I found out about the highway file. It's application depends on the software step in your ecu's. The best way to find out what your ecu's are programmed with is to have your preferred dealership connect to it and find out for sure. Another thing to keep in mind is that you may no longer be able to get this file enabled.

I'm not sure how many of these trucks were produced. We never had any in our area (and not many Midliners either). From what I've looked at so far I don't see any being built with the P1141 but I'll look some more.

Ok, so I missed HK Trucking reply, so that's a +1 Then another +1 for Rob Hatcity also gets a +1 I think I'll need a calculator if this keeps up much longer

Let me know how this sounds: #1 +1 for everbody involved (points for participating) #2 +1 for Barry for initiating it #3 -1 for Barry for letiing Other Dog take it too far #4 +1 for Other Dog for taking it too far #5 +1 for Rob for restraining himself #6 -1 for Rob for not participating as much as everyone else #7 -1 for Other Dog for not including Rob (which caused Rob to lose a point) The way I figure everyone is now up at least one point, but my math might be wrong. Does this seem fair, or am I over analyzing the situation?

One thing to keep in mind when installing this service file is that it sometimes causes the problem to worsen at higher altitudes at certain temperatures. We install this file with some regularity and it usually fixes the problem, but a couple of years ago, right after the switch to ulsd fuel, a customer brought a truck in with no real mechanical problems taht was popping/misfiring when accelerating under load, especially from a stop. I installed the file and I could make the engine backfire when sitting still if I held the throttle at 1600 rpm, returned to idle & then tried to go to full throttle. I actually blew a hole in the insulation of the building doing this. I thought maybe it was an ecu problem & switched ecus with another truck-the problem went away completly. Before changing the ecu I checked the datafile in the second ecu & couldn't find the number in my chart. It turned out to be some kind of "above top secret" file that Mack Product Support couldn't enable. Our DSM had to actually turn it on if I remember correctly. It was related to altitude and ambient temp. at 80 degrees. After installing the file everthing was back to normal and there hasn't been a problem with it since then. I haven't seen this happen with any other trucks since then either. It may be something that just occurs with some engines when certain changes are made (such as ulsd fuel). I think it was probably around the same year model as QCDrivers engine but in an RD688S chassis. I'll check back and see if I can maybe find out somemore on this for you.

I would agree with Mackpro68. The guage he linked to would probably be far simpler to install with the added benefit of being a manual guage instead of an electric one. However, if you want the electronic factory guage make sure to have your Mack dealership turn on the option in the mainframe before downloading a new datafile if you have your ecu programmed. Regarding the fuel level guage-it's probably the sending unit in the left tank, but you may want to check any shutoff valves, equalizers, fill caps, etc to make sure everything is ok before spending money on a new sender. I believe on your truck the fuel level sensor is fault enabled-the eml (lightning bolt) will come on, with code 6-1 I belive, if the circuit has high or low voltage or open circuit, however it won't sense a fault otherwise. This means a damage float or arm on the sending unit will cause erratic behavior but not necessarily set a code.

Looking at the literature from Bendix it looks like these are quite a bit different from what Rockwell had out. The Bendix brake doesn't have a power shaft (similar to an S-cam in operation) to wear out, hence no extenal slack adjuster. It looks to me like the entire caliper has to be replaced if the internal adjuster machanism seizes. Brake pads might be easy enough to come by and appear to be pretty simple to replace, but I have my doubts about how easy a caliper assembly would be to get your hands on. These also have brake wear sensors in them which probably means more electrical problems. I think Mack only started offering the Bendix air disc brakes in the last 2 years. I haven't heard anything good or bad about them but I don't know how many trucks were built with them. Maybe not a big enough number to base an opinion on.