Jump to content
  • entries
  • comments
  • views

a small step for man. ......



Good morning my fellow members of the Mack trucks family. I hope this finds you well and may even give you a wee laugh at my adventures.

As you all know, I've been having fun with my old Mack for a little while now and that one job always leads to another. Since we last spoke I've been having problems getting her to idle or run for any length of time. I was getting fuel upto the injectors but it would only run for maybe 30 seconds then die. Which after at least 30 years of sitting still is quite good going. But I am a very impatient person and I knew I wouldn't be able to settle until she was running better.

So after much head scratching, swearing and getting pi##ed off with the big hunk of junk I decided to go back to basics.

First of all I looked at the air side of things. All checked out ok so I moved onto compression, with my not so great experience with huge diesel engines I just made sure that the engine turned over and that the valves were properly adjusted. Lastly was the fuel. I was not so sure about the quality of the diesel and how long it had been sitting in the tanks so I decided to drain, clean and renew the fuel system.

Looking at the tanks I thought it best to remove the variable and just run the fuel from clean containers. This done I stripped the rear most fuel filter. What an amazing bit of kit considering that it was built in the 1940's. The sludge that came out of the bowl was quite disgusting and the wire gauze was a bit dirty so a thought clean and put back together. Next was front filter which I was struggling to get a replacement for but in the end I just matched a regular filter to the size of the old one and popped it in.

So I tried again to fire it up but the problem was still the same. It wouldn't idle or run for any length of time. By this point the steam was coming out of my ears. Thinking the worst I called it a day and packed in for the night.

I managed to get a cheeky wee half day on Friday and when I got home the sun was out and my better half was having way to much fun with the pressure washer to do anything so I rolled up my sleeves and started again. I was convinced that the problem must be coming from the fuel side of things and I remembered that when I first got her home and tried to get fuel up that the valves on top of the fuel pump were stuck so I pulled the fuel pump off.

After a little stripping I traced the fault to the main value in the pump. It was stuck solid so a bit of wd40 and a bit of work the value popped out. Who ever thought to put the pump so tight to the chassis rails should be sacked ! All things moving as they should I put it back together and bled the system. This time on startup the motor sounded sweet but the fuel was squirting out the pipe from the pump to the filter.

I replaced the leaking pipe and standard the motor. It ran as sweet as a nut and even revved up and returned to idle.

I am a very happy boy! !!!!

Now onto the drive train. ......Wish me luck.

Until next time my Mack loving friends.



Recommended Comments

everything will take some time. You got 40 years of "stuff" going on there. Glad to hear the motor is running fine.

Link to comment

cheers buddy. This project is going to be an emotional roller coaster but I am sure it will be worth it in the end. it's 5am and I am just about to go and play with it! my neighbours must hate me.

  • Like 2
Link to comment
Add a comment...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...