RS Disposal

My truck deals with alot of snow and wet salty road slush that get frozen and packed into the frame rails and everywhere underneath. Current have 1800 lbs of that according to the scale house at the dump. It took me a day with a torpedo heater to get the fuel line to where I could get it out. The fuel problem is still there so I have ordered a new lift pump and just replumbed the electric back in. The same issue is going to be changing out the air line from pump. In looking closer at the dryer and am pretty sure it is going to be junk from the corrosion from all the road salt. Going to pick up another one before I have the air lines made in case I need to route the lines differently. After cleaning the frozen slush out from around the rear of truck I noticed that the pinion is leaking pretty bad. Brake cans have oil on them. In checking oil level it is lower than I would of liked to of seen it. Finger crossed I didn't mess up anything inside the differential. Good time to do another gear oil change also. My truck only runs about 150 miles a week with 2 trips across the valley of about 45 miles round trip.

It is a working truck and I have bought numerous tools that have been needed to do the work.

not with the truck right now for a pic. I am familiar with that method of removing the seal. Just trying to get all my ducks in a row for when I do this job being when I have the truck at the shop I don't have my personal vehicle available whereas truck is staged at a different location for work

I am more of a light truck/automotive mechanic. Getting my feet wet with heavy truck maintenance and repair

Under truck greasing what needs done I noticed that my pinion seal is wet. Question is is replacing the seal pretty much straight forward as in with light trucks? Anything I should be aware of being I have never done a heavy truck pinion seal? 1979 Mack and I do believe it is the single reduction differential. Pretty sure I don't have a socket big enough so, off hand does anybody know the size needed I would need to purchase? Per factory shop manual looks like nut torque is 600-900 ft lbs. Only reference to gear oil is "GO-F-90". An online search for that number shows it being 75W-90. Is this correct?

I have used reusable fitting so I do understand what you are saying. I will look closer

I keep brake shoes, wheel seals, alternator, starter, most air valves that are on the truck (seems I have alot of trouble with those in a really cold winter whereas the truck is stage up canyon and can see single digit or lower temps on a consistent basis). Just recently did a total rebuild of front suspension all the way from springs, steering components, brakes and wheel seals. So I think those are good for a bit but as you say will definitely be monitored on an on going basis The fittings on the air dryer are no reusable ones unfortunately. But I have kicked the idea around of buying bulk hose and getting reusable fittings. I don't feel that you are picking on me. I value all of your thoughts and insight being I know what I don't know. If I thought I knew it all I wouldn't be asking questions. I appreciate anything and all you have to say Thank you

Not replacing the fuel line wasn't a matter of time, It was a matter of availability of being able to have one made over the weekend. It was the last FUEL line needing to be replaced. The inline pump isn't meant to be a long term cure. It is just another step in my trouble shooting process. Being the line wasn't wet anywhere along it's length with pressure on it makes me think that it wasn't sucking air. Being any older truck alot of parts aren't able to be locally sourced. I do have a new lift pump on order. My mindset is one that I need to know what was actually causing the problem and not just throw alot of parts/repairs at it in hopes that one of them fixes the problem. Time consuming and can be frustrating I know, but just the way my mind works. I haven't really addressed the air lines yet being the truck has no problem building air. I was just concerned about servicing the dryer. Once I get to the dryer job the lines from the compressor to dryer and from dryer to wet tank will be replaced alone with the signal, etc lines to and from governor. The truck is a 1979 and when my dad was running it I don't think it was maintained very well knowing that the arrangement he had with his brother (who owned a ski lodge in the resort) that every 4 or 5 yrs the truck is replaced. The truck have never run full time even back then. The truck then sat for 20+ yrs before I put it back to work Mile wise it only has 160,000 miles, but it it 47 yrs old so just is not really wearing out, it is aging out. My biggest problem has been sourcing parts as I found out with the engine breakdown 2 yrs ago. The truck only really makes any money thru the ski season (about 4 or 5 months) and then it only works two days a week for about 10 hours total, so there is not alot left over to stock pile anything more than than maintenance parts and smaller breakdowns.. I do totally understand what you are saying about a parts truck, but that search didn't go well back when I had my engine breakdown

Being that the tank to primary filter hose is the last one needing replaced I decided to try a wild hair idea. I spliced in an inline fuel pump (being the line was going to be replaced anyway so no concerns about cutting it) and powered it off a keyed accessory circuit. Powered it on and had about 20 psi at the injector pump. Started the truck and let it run for a bit watchin the fuel gauge to see if having the lift pump still in line (if indeed the pump is bad) would have any adverse effect on the fuel pressure. Being it was a work day I had to climb canyon I decided WTH and give it a try being after about 15 minutes of fast idle the pressure seemed to stay about the same. Climbed the canyon with no problems at all. I do believe I felt there was a bit more power available, I did notice that the boost pressure was a little higher and the the pyrometer was a little higher (neither was crazy high). Correct me if I am wrong, but my thinking those factors would mean the engine was getting better fuel flow.

I totally understand your comment. My problem about truck not running is it is a garbage truck and I service a ski resort town which in the ski season is extremely busy particularly on holidays. non of my accounts have the space to miss a pickup day which is 4 or 5 times a week.

thats the last hose i have to replace. Would of done this weekend but my hose place is closed on weekends and truck has to go to work tonite. It's hard to work on equipment that also has to work every day.

haven't actually checked the vent it self, but I did try running with the fuel cap loose. I will try the drain back tee and see if it makes any difference. Being a one man show with only one truck and this being my busy season and truck having to also work while I try to figure this out makes for some long frustrating days

truck seems to run fine around town but when I am climbing the canyon occasionally it will start to miss (more than just loosing power) and I would have to pull over and let it idle for a bit. Then I could start back up again. I do understand about a liquid filled gauge, but would think the gauge attached after the secondary filter would mellow the fluttering a bit. I did notice a couple of times that the gauge did drop to zero for several seconds. I did pull the plastic check valves and they did look ok, but don't have new to compare against. Truck only has about 160,000 road miles (not sure about motor miles being there is a pto running a packer) but then again it is 47 yrs old and sat for about 20 yrs before being put back into service about 8 yrs ago. Truck only really works part time anyway, but I do know stuff breakdown with age alone

from what I have found its about 15 psi. My question was the fast fluttering

pulled the return tee of and took apart. everything looks good there. Haven't pulled the cap screws yet. Put a fuel pressure gauge on the injector in line and at idle the needle fluctuates between 10 and 30 psi. Doesn't change much if I go to a fast idle. Should this reading be more smooth rather than fluttering? Would this be sign of a bad fuel pump? I did pull the caps and the springs appear ok and the plastic check valves are ok

not exactly sure where that is. I am not a heavy truck mechanic and still learning my truck all beit it is older

lately I haven't been getting anything out of the purge valve when the system reaches 120. I agree that the line between compressor and dryer should be replaced. It is definitely on the list of things to do with this truck. Right now I am also fight a fuel problem which I am hoping is old/bad fuel lines. The truck was never maintained as it should of been when my dad was operating the business and then sat for 20 yrs before I opted to put it back into service

i am working on replacing most of the lines one by one on this truck being it is a 1979. I know rubber breaks down just from age (not alot of miles but 47 yrs old) and this truck has seen alot of road salt. The problem I am having is that once it got cold the truck had a hard time building air. I replaced the governor which seemed to help a bit. Air pump was replaced about 5 or 6 years ago. Being a garbage truck it does alot of start and stopping.

the air dryer is fairly tall as compared to what I have seen on other trucks. Plenty of room whereas the dryer is on the inside of the frame rail and nothing else around it

I am wanting to service my air dryer being I can't find in maintenance records my dad had for the truck when it or if it was last done. I can't find a tag on the dryer or and specific info on it in the factory service manual. Not sure if I can actually get it apart being truck sees ALOT of road salt in the winter. If that is the case what style of air dryer should I be looking at. A google search shows there are quite a number of different dryers available.

OK, an up date on my problem. The issue is now that when climbing the canyon occasionally the truck will start to miss to the point I have to pull over and let engine idle for a bit at which time I can continue on up. Replacing the in/out fuel lines from the secondary fuel filter didn't really make any change. I replaced the fuel line from primary filter to the fuel pump, again with no change. Still have to change out the line from tank to primary, but that one is alot more time consuming because of the way the factory routed it. Thinking I will route it in a more direct fashion from tank to filter rather than down along frame to behind trans and across and back up to filter. The line doesn't appear wet anywhere, but being on the suction side I am thinking it might not be. This line being under the truck is exposed to alot of weather and road spray/salt. Plus the truck is 47 yrs old. Not alot of miles but I do know rubber breaks down because of age. just trying to learn my system also and whether or not this could be a problem. The first pic is of my intake manifold with where I assume this senses boost pressure and sends a signal to the injector pump. (where my finger is pointing) The larger line is truck air and the smaller is the one that goes around to the injector pump. The third is on the side of the injector pump where the small line comes down from the row of injectors and the larger line goes back to the tank. On another note the couple of times I have replaced/taken the secondary fuel filter of it hasn't been completely full. Maybe about 80%. In my way of thinking it should be full. Would this be an indication the air is entering my fuel lines somewhere between tank and injector pump?

I want to thank everyone for your replies. Please excuse my terminology whereas I am a small truck/auto mechanic, not a heavy truck mechanic. I am just a one man show with only one truck and I do try to do most of my repairs\maintenance myself. That the way my dad did it and taught me.. I may of found my problem, if not it was a problem only going to get worse. During some routine work I noticed a fuel line along side the frame rail going from what I assume is a fuel pump on the side of the injector pump the was wet and the under side of the truck and leaf spring also wet. My truck has 2 fuel filters. primary has the line from tank then goes to this fuel pump. From there the line goes to the secondary fuel filter and from there to the injector pump. I am assuming these last two lines are under pressure hench the reason the line is wet from leaking. The other lines are suction lines. I noticed that last time I replaced fuel filters that the secondary was only about 80% full. The line that was wet was the one from the pump to the secondary filter. So my thinking is that for whatever reason pressure was being lost and air introduced into the system. Replaced the two lines off the secondary filter and I guess time will tell if that was my problem. As soon as the weather gets a little better will be replacing the other fuel lines. Don't have a shop big enough to get truck inside so it is all outside work.😪

I believe the fuel tank is good. when I did run it lower on fuel I did shine a light into it and it looked clean

when I snap the throttle the rpm's don't run up. It immediately drops back down to idle. Truck doesn't have alot of miles, only 160,000. It's just old but other than the occasional surge it runs and pulls great

That was on thing I was thinking might be, a fuel restriction. When I changed fuel filters, thinking it was plugged filters, and I cut one open there was a black residue in the filters. My thought weas that maybe the fuel lines were beginning to deteriorate internally being the truck is 1979 (46 yrs old) I have purchased new fuel line, just haven't replaced it yet