Lmackattack

Well, I added 40-45 gallons of hyd fluid in my 126 gal tank and it dumps and works just fine with low boys and short dump trailers. The amount of fluid capasity needed is dependant on the hyd piston. I havent pulled a long dump but would suspect it needs more fluid than a short dump because of its hight travel? are you running 2 fuel tanks right now? what size are they? if you have 2 large tanks you could convert the pass side to the wet tank. or if you want to be real trick. have a shop seaparate the pass side tank for fuel and hyd fluid. something I considered but dident want to spend the $$$ on. im not a fan of the top of frame mounted tanks that sit behind the cab. ugly in my opinion Trent

details please !!!!

Hello and welcome to the site Insurance....http://www.racensur.com/ ...pretty cheep if you use it for shop and show only plates.... go to to your DMV and ask for antique plates. if the truck is an anteque I dont think you need a CDL to drive. Diffrent states have diffrent laws. Check at the DMV. I will say It does help to have one if you get pulled into a scale house. you wont need fuel tax stickers,log books or that other commercial junk with antique plates. Again just check with local laws to be shure in your state. In IL You need a truck with air brakes to take the tractor/trailer CDL test. not shure if traile needs air brakes or not.

Could it be a timing issue after the rebuild?? did you mess with the timing or anything that would upset performance. I guess what im saying is check with the simple stuff that you can perform. fuel press,boost leaks, etc... if all checks out dig deeper into engine programs and computer stuff. the price for an engine hp "upgrade" is pretty steep here in the US as well. I know that you guys get higher HP upgrades than us over here . whats the cost for a engine code scan at your dealer dealer? that may be a cheep option

crank or rod bearing would be mu guess? did the knock change when you let up on the peadal? sorry for the bad news Trent

I know you could get a Cat in a superliner, and I belive the ultraliner and superliners shared the same frame???? someone will know for shure for me, I would drive a old mack engine before a new cat was under the "dogs house"

I see your point Brad, and its a good one. I think many people are afraid that Volvo will do to mack, what they did with White trucks. I agree that mack is better off built under volvos name than to not be built at all. Volvo is a strong company,so thats good thing. I just hope they dont suprise us with "bad news" I hope the MP8 is as good as some have said. I have heard it compaired to the old maxidynes "can feel the power band" the elec versions of the E7s shure were not known for grunt. I also think it will be a very good move if they put the big HP (600hp?) engine in the mack for the heavy haulers and low boy trucks. 405hp is not huge power that most owner operators look for. dont get me wrong 405hp is plenty for me but there is a market for big hp engines, and mack is completly out of that market currently. cross my fingers

Scott the cans were pretty cheep $5-$7 dollars if I remember correctly. i think 2 cans did the dash and interior cab steel. I have not found the meterial used for the panel faces. I ended up getting some panels out of a parts truck that was in fair condition. It does seam odd that you cant get interior parts for the truck when it was discontinued a few years back. I tried looking up parts for a few year old R,RB,DM, etc... had no luck will all those vin numbers? I even tried for the R model ledgend and had no luck. Trent

Mack sells a spray can that matches the silver or tan paint used in the R models. I sprayed my vinal dash and inside the cab with it and it is holding up pretty good so far? I had trouble getting interior parts for my R model. I even tried using a a vin number from a 4 year old R model. I thought it may have just been my mack dealer not wanting to help but I did try another dealer and got the same answers?? let me know what you find

just for refrence if you ar looking for a 4.xx ratio. Many R models with the 6 speeds (1.1 direct trans) came with high 3.xx to 4.xx rear ratios a 4.17 rear with direct drive trans will do about 63MPH ish at 2100RPM with 24.5 rubber a 3.87 rear would give do about 68MPH at 2100RPM with 24.5 just some options there for ya.

"gold paint" is just another reason that it is likely a 6 spd

Very cool Barry That would be neat to have even if it was not my truck when new. Hell, I wasent even born yet when both my trucks rolled off the assembly line

Come on larry give it a shot . Its not as hard on the truck as you think! just dont use LOW LOW!!! I see lots of twisted drive shafts with that gear. Missed both of the Truck pulls this year. one because I was out of town the other was 2hrs south of me but I was just to damm tired after working all day to make the trip. Maybee next year?

here are the pics of the internal destruction. its hard to see but the "tear" goes all the way to the turbine blade aera and bypassed most of the snail housing. Enjoy

fixed I pulled the turbo off the manafold and found the intire center separtor wall of the exhaust snail was deteriorated and missing!!. I could clearly see the back of the turbine blades LOL. i think that would explain the issue with low boost . I put the "new used" turbo on and I can now get 15 psi at 1100RPM and a full 25 psi at 1900RPM She pulls like never before and EGT temps are very low at cruise. this was fun but glad its over.. Trent

2nd Update: I did a "sniff" test today. With the truck running I sprayed either around the charge core to see if it was sucking air..i.e leaking. no change in engine speed or sound. I also sprayed it in the tip turbine fan to see if it was leaking on the inside of the core aera. no change in engine sound. I removed the turbine fan to inspect the core. it looks clean but lightly sprayed it down with water to see if any dirt came thru. all looked clean. with the turbine fan removed. I plugged the turbine feed pipe hole with a cap and took the truck around the block to see if I could get more boost. With no boosted air being able to bleed off to through the turbine fan pipe. i was able to get 16 psi of boost when I held my foot on the brake to give the engine a load. EGT temps were obviously rising very fast with out the turbine fan installed, so I only did a few test trials. I still cant hit full boost or close to factory spec boost. It did however make the boost a little faster than with the fan installed so it leads me to belive that there is a large air leak that I have not found or that the turbo is worn out? Im leaning towards the turbo fins are worn out and not allowing it to make factory boost levels? I should have a spare 285 turbo tomorrow to test my thoughts. What do you think? on a side note the check valve on the fan inlet had a rubber flap that was a little worn as well. it was more or less contoured to the metal bridge that regulates how far the flap can open. I will be replacing that flap if its still availible at Mack just to elimanate that as a problem. Thanks for the help guys.

Great pics Don, sorry I missed you heading over Donner pass. I went thru there around 9-10PM, maybee next time? Trent

Update: This week I installed a factory wire lead from the EGT probe in the Exhaust pipe to the EGT guage. Temps are still high under load. I checked the crossover pipe and all the rubber clamps, no signs of boost leaks. I was only getting 14 psi of boost so Today I Replaced all the exhaust manafold gaskets, studs etc... to make shure no exhaust leaks. my boost guage is now reading 15psi on a hard pull and temps are still high. this past winter when I took put the boost guage in I was getting 18 psi but I figure that was from cold temps? I asked my local mack dealer what boost psi I should see and HK you were correct 18-22 depending on the condition/ age of the motor. This motor uses no oil and when I had the manafold off there were only 2 cyls that has a very, very slight trace of oil seaping past from a valve or something. It did not look like a caked mess that some old engines have. all looked normal to me. Im thinking that this low boost is possible cause for the hight EGT. I was thinking about swaping a diffrent 285 turbo on to see if it makes more boost. my turbo has a few hair like cracks in the snal but no exhause leakage from them??? only thing I can think of now is the charge air cooler is leaking? does the air that goes thru the tip turbine make its was back to the intake manafold or does it blow out to the out side air? I cant hear any air escaping?? Thanks for the help Trent

ebay has the round knobs in diffrent colors all the time. I have a cracked clear on you can have free.

My advice is if you dont own a house or have huge loans to pay off, test the waters to see if its a for you. After you get your CDL I would reccomend start with part time dump trucking on weekends.Lots of small companys need fill in drivers for weekend help. Its a good way to get time behind the wheel and on job sites. to find solid work it really helps if you have honest friends in the buisness. Not just so you can work for them but for there contacts if they dont have any work for you. It also helps if IT STAYS DRY!. here in Chicago people can get $75-$80 an Hour for semi dump trucks, $100 an hr and up for low boy moves depending on the machine moved permits etc... Some times we charge by the load and get $210 a load if we haul out of down town to a far away dump. most dumps are charging around $50 clean clay. Some dumps close to the city are charging $65 and up!!!. 4 loads a day in traffic is about all you will get unless you go back for a 5th "preload"to get rid of early the next morning. So its good if all the stars line up the night before. If you get D.O.T fines or mechanical trouble your day wages is likely wasted or even worse puts you back. I am very suprised how some of the new guys buy a brand new 100k rig to play in the dirt. and cant figure out why they have no money. Most of the small outfit guys that have been in busness for a long time still like to use older equipment because it sometimes more cost effective. I see new lowboy trucks alot but the majority of the dirt trucks are all 7+ year old macks. so in the end test the waters slowly. and learn from what the successfull owners did to survive. Let us know what your plans are. Trent

Not shure if this is the "exact" engine in your truck but take a look. Welcome to the site Trent http://www.macktrucks.com/assets/mack/prod...i4271001417.pdf

Thad with most macks you can use the first few numbers to find the models "standard" version. I cant find a RS/RL755 in my book but for some examples look at Dan Brunos web page for 1977 RS/RL models. http://www.stlouisdumptrucks.com/convoy9-04b_007.htm A RS/RL786LST will have a 6 cyl 285 hp mack A RS/RL795LST will have a V8 mack with 325 hp ....etc.... the digits after the model number are most likely the build count. When you get the whole 13 vin number you can contact the mack museum and find out what the truck came equiped with including options from the factory. I just looked and it again and it looks like that truck will make someone verrrrry happy. wish I had more room. it would look great next to my RS. Trent

I stop counting at around 95 deg. its been hotter than that all week with the heat index.

Thats a good looking truck Thad. It at the right price also! I would love that truck parked next to my RS !!!It does look to be a RL looking at the thick rear rails. Sounds like you got it down with the RS RL diffrences RS700"L" is a standard designation for lightweight models. I think the alum doors were an added lightweight option. Like said above Alum rails if not looked after properly can cause problems later on. I would not want a used truck with alum rails and heavy rears for the reason of added stress to the rails. Its not commonly seen to spec a truck with lightweight alum rails for heavy haul use. at least not in my aera. The few RL six wheelers I have seen with alum rails all had frame cracking issues. Just my opinion on your rears spring comment.