RS Disposal

Running a 15 lb radiator cap RPM's are around 1800. I can run around town all day long and engine runs around 180-190 according to the temp gauge

I will use my heat gun tonite when I go back up canyon and check radiator temp. I stop to let cool once my temp gauge hits about 220.

truck is back to work and appears to be running ok. Only issue, which started last summer before it died, is it gets hot climbing the canyon where most of my pickups are. Canyon is between 6 - 9% grade and 8 miles long. I just watch engine temp and stop and let it cool, which it does within 5-10 minutes at idle, and continue on. In the valley it runs between 180 & 190 all day long. Pretty sure radiator needs to be rodded out. Nothing has ever been done to it since new and truck is 1979. Will have to just watch engine temp until my slow season before I can take it out of service for several days or so again. I think at the same time just for shits and giggles replace water pump, fan clutch and thermostat. Here is another newby question as far as turbocharged big diesel engines. As far as the turbo boost is concerned, what exactly determines the amount of boost you get? Is it the diameter of the compressor housing? New turbo compressor housing is larger in diameter, but also not as wide as original. This truck has never had a boost gauge, so I have no comparison to go by. Around town I am running between 6-10 lbs boost. When climbing canyon I can get as high as 18-20 lbs boost. Climbing canyon pyrometer shows 600 - 700 degrees and around town 400 - 500 degrees. Sticker on the original gauge says max temp is 1125 and it doesn't get anywhere near that and the sensor is in the same place as original. Again I want to thank everyone for their help and insight that was given on my learning experience over the last several months. Here's wish each and everyone of you a joyous new year and wishes for a great year to come.

Well, after 4 disappointments on getting a rebuilt turbo I was finally able to get one and get it installed. According to the rebuilder it specs out to be the same as my original, but the compressor housing is larger in diameter, although narrower in width, which presented a couple of minor problems in installing. I had to undo a frame strut and also install a 1/4 inch spacer because the housing would hit a bolt on the rear of the engine. Other than that, everything seemed to line up ok. When I have the engine running at idle I am picking up noises that I don't remember hearing before. Not bad noises I'm pretty sure. Most likely I am thinking I am just being much more intense in my listening than before because of the major breakdown I just had to repair. It has been a tough and interesting journey for the 3 1/2 months my truck was down. Tomorrow she goes back into service with my fingers crossed. On another note, I decided to install a boost gauge, which it never had before, and was wondering what kind of boost pressures I would be looking at and whether or not the slight differences in the turbo compressor housing would have any great effect on that. I also decided to reinstall a pyrometer, which it did have years ago but when some exhaust work was done at one time the sender was never reinstalled and being the original is no longer available, I put in an aftermarket. A sticker in the cab by the original gauge states 1125 degrees (I think) max. Is this about what I would be looking at. My other truck does have both of those gauges, but it is a much larger motor (Cummins N14) and off hand I don't remember what it would run on those gauges anyway. Also, if anyone out there might need, I do have a new in box Mack 185606 CHRA and a never installed rebuilt 4LE-292 turbo, both of which I purchased in my trek of trying to get something that would work. I will post here how the truck does on her first day back to work. I want to THANK everyone here for all your help and guidance, this forum has been invaluable in my learning experience.

this is a cab over garbage truck. The VIN shows it as a box truck according to the dealer

I wou8ld really appreciate that

I did get my truck running, but locating a rebuilt turbo is getting impossible. Does any of you guys hjave a source to try or a source for a seal kit for this 4LE-303 turbo. This one leaks oil out the exhaust side Can anybody tell me what the difference is between the 4LE-303 and the 4LE-292 or 4LE-556. The pictures I am seeing they look similar

My other truck is an Autocar with a Cummins N14. Unfortunately that one has transmission problems that I really should of fixed before now but life just keeps getting in the way. LOL

yes, it is a dynatard. Wish it was the jake brake. About the only thing it is good for is to help with the shifting of the 5 speed. No where near a good as the jake on my other truck when coming down canyon. And no, there is no riser

my rocker covers just have 3 bolts that go thru the top with shoulders on the bolt

nope, mine is just a 2 valve endtb675

I actually have 2 sets of new gaskets

It does look like Permatex does still offer "high tack"

Good to know. I was planning on using silicone cause I know my rocker covers were leaking

Now if I can just nail down my turbo parts or rebuilt problem

Thanks, I did the 50 to 125 to 200 ft lbs The retorque spec says 225 so I think that is what I'll do and then just watch for any leaks

My thoughts exactly as to how many engines actually go back to the shop for a retorque. My truck just runs in the city with about 25% fast idle time running PTO. Very little freeway, and at that my truck only really works4 days a week in winter and 2 days a week in summer and even at that an average of 6 hrs is all. It don't work real hard LOL Think I might just got with the 225 ft lb spec ot calls for on the retorque

still wasn't able to find what the differences actually are between the 185604, 185605 & 185606 CHRA cartridge so I ordered a NOS 185606 based on numbers cross referencing on this web page for a 185604, http://www.invasionautoproducts.com/19mava4letu11.html . States this turbo is compatible for my mack number 631GC4101P12. Well, I think I may of found what the difference is. The 185606 won't work with my turbo. Compressor side is much larger so I am thinking the difference is probably different sizes on the compressor side. Turbine side appears to be the same but didn't go any further. So, if anybody needs a 185606 new CHRA cartridge I will be listing it on ebay for what I paid $350 plus shipping. On another note, I did get my head back and am in the process of putting it back on. Question is, how important is the retorquing of the head bolts? Do I really need to run the truck under a load for 1/2 to 1 hour or just let it run and warm up for 1/2 to 1 hour? Retorquing will require removing the rocker are assembly again being it covers several of the capscrews. Fingers crossed everything goes good on reassembly

in my search for a turbo (mack number 631GC4101P12) I am finding quite a few sites that are listing the turbo if I use 4LE-303. But there are a few different other numbers that keep coming up. What is the difference between 185604, 185605 & 185606? I am totally confused

Still don't havew my head, but machine shop was confident mid week this week. Was informed by my turbo people that my turbo is bad. He is having trouble sourcing parts thru his normal vendors. So I guess I need to start my own search for either a good rebuildable or an already rebuilt turbo. Any suggestions as to a staring point would be appreciated. Mack part # - 631GC4101P12

Pretty sure I might end up having more questions. Machine shop recommends all new parts. He has the valves and guides and the dealer I believe told me all valve train parts were still available so I am headed to the dealer to get them ordered. Going to take turbo in to make sure there was no damage to it also. Another quick question. I didn't notice and valve stem seals when the head was disassembled. Is this normal for a big diesel engine. Are there actually seals available for them?

Thanks for all the insite. Got word back from the machine shop. Heads was magnafluxed and no cracks. just need to pick up the necessary parts to do a valve job

Being I didn't have a 5/8th tap or die I did order a new pair to do just that