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Make sure you have the outer cylinder in corectly the snapring towards the rear!just pull the cylinder off in the truck and check it! also disconect the touque limit line from the reversing relay at the engine and plug it! both ways!

Three things starting with the cheap and easy!Thermastat replace it. does it have a thermatic or air fan does it operate correctly? Rad is it clean?and one more thing if it has shutters are they opening?

Yup I agree totally with you Glen and Rob , another thing can happen too is a guy can create a leak by tring to do a repair those hoses tend to get stuck to the tubes and leave remnance on the tube which can cause leakes after reasembly. ,another question always asked Why did the job take so long is a comon question!The answer is I DID SOMTHING I REPAIRED the problem didnt write a novel on how too! Not to toot our own horn but that is why we built the boost plates in the picture I tests the Whole engine charge air system. that leak would have showed it self in an instant and probably more of them!another fairly comon leak on these engines is the inlet and exshast gaskets. Anyway , Glad it was an easy fix for ya! Anyway talk to the service people if they don't credit you back somthing get eaven!

That happens lots ,once lines are disturbed the injector orings will leak.

Id keep on drivin its likly the orings are bad on the injector did you pull the injetcors when you did the job?

[quote I\'m not so sure now. I liked it a whole lot better when I could overhaul one on the side of the road. ME TOO! You just do the best with what is put on your plate like it or not!I have noticed with theses engines after the inital programing issues were delt with the most comon failures are physical and mechcanical some, Very illusive in nature. Only experiance will tell ya the answer quickly what is wrong ,and sum times that don\'t even work. Below is the tool we use to check THE WHOLE engine for boost / exhast leaks and other wierd and wonderfull failers ,turbos passing exhast gas into the base boost bypass valve failers egr coolers leaking into coolant all can be tested in one operation with this tool on ANYONES engine for the most part, we built this as I said before ,doing the best with what we had avilable. we use it almost daily.

Guys ya can pretty much go with the simple stuff to a point on these engines but then you get thrown a curve ball EGR.Adds a new dimension to the fuel air theroy.Heat, boost preasure exhast preasure inlet air temp humity exhast leaks,yada yada,Not a simple engine anymore, sensors have targets to meet if they don't meet the targets they don't run right. there anit nothing simple about this problem, to many added features to monitor.Its not just as simple as air vs fuel these days.

First guess egr valve is sticking Second guess did they check the boost bypass valve gone haywire? 3 EGR cooler plugged.

OR a flat cam lobe!

I had a pm from mackcl96 asking if rear wheel horse power was the advertised HP for mack trucks at one time! I accidently deleted your pm brother sorry!Anyway My answer and I will stand corrected but to the best of my memory The fly wheel horse power was the advertised HP of the truck It would be a unfair and hard to compair against other vendors engines otherwise! Having said that for quite some time duing the 80s and early 90s all the trucks came with a dynotested tag in the window Its anyones guess if they actually draged full HP out of them on the dyno before sending the trucks out!I do know also we had the odd customer take em to task on the HP of the odd V8 bitching about no power to find the 500 hp engine would be making 488 /470 to the ground which aint to shabby for an un touched engine.The guys at the dyno place also comented that you could put a cup of coffee on the hood while dynoing and it wouldnt budge where other engines would shake the dam thing off the hood!

ys its the t looking fitting at the end of the fuel pump with the small line an one larger line on it.

What your discribing sounds correct for an american bosch pump. His pump is robert bosch.Maxville has the drill for that! I.d be curious if the truck is a six speed or other econodyne does not sound right for 237.also if while pulling under load you still see smoke if so it may be leaking boost!The older engines had a stamped metal intake that could split and leak!

Could you varify which fuel system you have rob bosch or american bosch?

We only sold a few of these but fom what I remember the jake was on one seting and both on the other.

Low operates jake only! hi operates jake and stealth.if you want it to work properly the steath needs to be there!

stealth is a jake/ exshast combo They usually work well when both are workng!Can you hear the jake working? can you feel a diffrence between hi an low setting?

Beer can will work too! Shim material is good as well Never had that problem with the joined gasket!

Welcome to the site! Are you using the one peice gasket the old style gasket came with open ends the new style the ends are joined. we used to put a slice of aluminim pop can in the corners to hold them in if using the old style.A 1/4 inch sliver of pop can an inch long usually did the trick. But we have had no problems with the new style gasket.

I would like a little more info!What year is the truck! Is the exhast temp down or up!You may have a failing fuel transfer pump. or bad drain back valve low exhast temp!How many times was the code logged for the failed eup.The other thing is if you changed the pump your self you need to have the eup cal code installed in the ecu for perfect injection control.

I beleive the arrows face out!If you did put them in back wards I highly doubt you would hurt anything!But also if you put them on the inside you can't see them at all that would make no sence for assembly purposes .The main thing is to have them all the same direction! this is a lesson to keep your tires the same size if possible! Have you replaced the inner and outer cam as well?If you are replacing the outer cam be sure to use lock tight on the nut and its torque is 1200 ft pounds or one heavy duty 1 inch air impact!And the inner cam needs the slots facing the rear! or it wount oil correctly. just a few pointers!

I would have a reputable welder repair the crack and install the insert if its out of warrenty.They arent putting them inserts in there for nothin! We have done only one of these and the truck had been severly punished!Not impling your beating it Because there was an odvious problem with the rails if It had tsb.

Chip check out the other blow by post! http://www.bigmacktrucks.com/index.php?showtopic=8344

68 It maybe the turbo You might try building one of these and see if the turbo is causing this! http://www.bigmacktrucks.com/index.php?showtopic=8344

Mainly for me anyway It has taken any pride I had in the product I have worked on for the passed 30 years and chucked it down the tube!The above statment ,the hood and the bulldog on it I stated 2 years ago this will happen in my opinion, there aint much left now you need only get on your creeper and coast under a mack and a volvo and you will have a hard time seeing many diffrences.Once the cab is gone it will be the same old same old. Autocar GM White volvo mack! Had they left in place some of the solid mack tried and true ideas in the construction stuff they would still have somthng to brag on! BUT that aint gona happen. there riding on the coat tails of a once Great product subsituting rubish in its place!

Well done, And your welcome. Anytime.