Lmackattack

ok good just wanted to make shure before i go looking for one. Thanks Trent

Do you need a special cam for a Jacobs engine brake on a 285 mack?

mine were 3.87 from the factory (1978) currently i have 4.17 that were pulled from an "F" model Mack cabover, these are of the standard cast iron diffs. My 65 B model has 5.73 cast iron diffs. on alum walking beam. Trent

i believe that you are talking about The diff drop ins. i will have to check my build sheet but i believe my RS mack cam factory with alum drop ins. ? CRD92/93??

Our Local ATHS chapter stopped for some eats 2 years back. here are some photos. Trent

i adjust them the same way you do. Sounds like the valve is bad,bag is bad or a leaky air line. That valve should hold air when parked. only time it should louse air is when the cab moves and alows it to dump. Could you relocate the valve to a place that does not interfear? Trent

Well you have alot of options I guess. You can buy a 80's-90's R model(pre electronic engine). They are cheep, simple and reliable but would likely need to be freshen up as many were rode hard and then parked. If you can hold a wrench it will be a very cheep truck to maintain as all the repairs can be done by you or any mechanic i.e no lap tops needed. If you do any off road work spring ride will be better than air for traction. many R models can be found with air ride cabs to soften the road and come with 285-350HP/ 6,7,8,9,10,12,13,15,18 speeds and a few with air ride rearsif thats what you want. The 90s CH macks are almost as good (my opinion) as the R models. The Ch has a larger cab and has more comfort but I dont think they are owner operator friendly with the electronic engines. they also dont put the HP down like the mechanicals did. The good thing with the CH is that you can easly find them with more options than the R models had. around here the R was a work truck and they were speced that way. The CH has more of a in between mack and thats why you can find alot with air ride and off breed componets. Parts for Ch models are widely availible thry mack.. Sadly R model parts are begining to thin out. so this may be a selling point to you. As far as pulling power in the mountains the R models and CH models cant be compaired to the loog hood OTR KW and Petes as they dont have the cubes under the hood to realy compete in that game. You will find a few "RW" or "CL" that have 500+ power but thay will cost alot more just for the engine option. If you are new to trucking stick to what you know and learn from there. it will save you more in the end and you can always upgrade to a flashy truck later. I run a 30 year old mack part time for the last 3 years. never had it at a dealer yet for repairs. if I cant do it I have a local guy make the repairs at half the cost. cant say that about these new computer trucks.. good luck Trent

http://www.uphs.org/4023move.html

nice rig!

from 0 to 125 psi takes my R model w/new compressor about 4-5 mim at low idle RPM at high idle takes about 3-4 min

UP Big boy 4-8-8-4 p.s look at the front axels

Glad you found part of the problem! let us know how the new nozzels work out.

This place HK?

looking good glad you got her home. some degreaser, and fresh paint should bring her back to life quickly Trent

are the slacks and S-cams greased up good? they can start to stick after sitting long. jack up each corner and see what wheel is not released, the wheels should all turn by hand with not much effort. if that hand brake is the issue the pads are sticking and the mechanics of the assy needs grease or some help. Go for a spin and see if the park brake drum gets warm/hot Trent

Cool find there! Would love to see it in action against the oem engine. Trent

anywhy?....EPA

Rob i just looked in my mack service book that the mack museum sent me for the old B model and found something that maybe the issue but not shure? Page 4-11 it does not show the "v"style pump but discribes a device that advances /retards the fuel timing per "x" RPM. just a thought.. i dought its something you have on your pump. but.... Trent

Well boost seams ok. that kind of press is very good for an olddog. i get 24-28 with the fuel turned up on my 6cyl. i guess you need to check the fuel return and injectors now? it sometimes only takes one bad injector to throw alot of smoke. My RS throws clouds only when i have the puff off(dash switch operated)When its operating normal it has a grey hint from the stacks after each shift. Hopefully FJH on this site sees this. He knows the old V8s pretty well. my 6cyl barly starts below 30 deg. plugged in she fires right off unless its -0 and below then she chuggs a little.

!! :ttiwwop: !!

how is the boost from the turbo? my guage reads about 1 lb of press just at idle. if the a/f ratio is way out of wack it can blow alot of black under a good pull. Before i found that i had a bad turbo on my truck i was throwing a good trail even with the puff working. can you check your fuel retern press? Trent

im not up on the old V8s Rob. i want to say the E9 has a puff but its a newer engine. Does your pump have an air line to the front or back of the pump. is the pump a "V" or inline ?

"East" coast R models all had the wider rails up front. Only the western RS/RL "R"models had straight rails. My advice is to register the truck with the B model title as the emisson laws are less strict and you could put cheep historic tags on if its not for hire. insurance is also cheeper with vintage tags!

Air ride is for over the road or limited off road use. There are some "offroad" air ride set ups out there but they still cant beat springs in the offroad. Camelback is the way to go for traction and simplicity in the off road. A spring ride tractor with an air ride cab will cut alot of the harshness out of rough roads.

you made my night HK! HA HA! wernt some of the latst duplex models quiped with an air actuater for the aux box??? never seen one in person (up close)