thomastractorsvc Posted January 5, 2017 Share Posted January 5, 2017 Fixing to tinker on the new dog. I spoke with the previous owner by calling a number I found in the cab. Nice guy. Any how he mentioned that if the truck is parked on a angle it will loose prime and he replaced all the hoses the transfer pump and filter housings to see if he could fix it. If it sits on the level no issues. I went and checked some stuff and then parked it on an angle and sure enough lost prime after about 2 days 1 day was able to start 2 days cranked about 20 seconds cracked the line and no fuel I pumped it up and it fired. He said he replaced the transfer pump thinking it was that but I am not sure if it is missing a check valve some where. Quote Robert"I reject your reality and substitute my own." Link to comment Share on other sites More sharing options...
Mackpro Posted January 5, 2017 Share Posted January 5, 2017 Check the "U" shaped fuel return jumper pipe between the heads/valve covers. Make sure its not wet around this jumper. There is a check valve on the injection pump where the return fuel flows out. There are about 3 different styles, a couple of styles have a spring and check ball that can be shimmed for more fuel pressure. And on the later VMAC pump it was a simple solid fitting with a small hole drilled in it to make a restriction to create back pressure. The transfer pumps would sometimes leak but usually leak fuel into the oil pan. Quote Link to comment Share on other sites More sharing options...
cstaples Posted January 6, 2017 Share Posted January 6, 2017 Check the fitting on the front of the front head. It has a small plastic line that runs down to the back of the pump. I had to replace the fitting on mine, it has a small rubber thingy in it. My 91 E7 did the exact same thing yours is doing and that fixed it. Quote Link to comment Share on other sites More sharing options...
hatcity Posted January 6, 2017 Share Posted January 6, 2017 park on level ground.....you're welcome 1 Quote Success is only a stones throw away.................................................................for a Palestinian Link to comment Share on other sites More sharing options...
Timmyb Posted January 6, 2017 Share Posted January 6, 2017 My truck would do something similar. If I parked on a lean the fuel would run to opposite side to pick up. Problem was my pick up tube was cracked. Hopefully yours is as simple as that. Quote Link to comment Share on other sites More sharing options...
thomastractorsvc Posted January 7, 2017 Author Share Posted January 7, 2017 14 hours ago, Timmyb said: My truck would do something similar. If I parked on a lean the fuel would run to opposite side to pick up. Problem was my pick up tube was cracked. Hopefully yours is as simple as that. The previous owner already replaced everything to the pump and even got the fuel gauge to work. I have been busy and we got snow so I have been keeping the Dump in the shop with my pickup so probably Monday or Tuesday if I am not working I will pull the truck in the shop and check it out. I know on some newer cats they have 2 or 3 check valves that are located in a couple different spots and if you didn't know you never find them. Being its a VMac I don't have a service manual yet. Quote Robert"I reject your reality and substitute my own." Link to comment Share on other sites More sharing options...
LTR Diesel Posted March 19, 2019 Share Posted March 19, 2019 Hi guys. New to this site and in need of opinions. I have a 2001 Mack vision 460. I am told the engine is not original as it is a non electrictronic engine. I have fuel leaking from rocker box cover down between #4 #3 heads. When running, I sprayed Beale clean on block to clean it up and find the source of the leak. When I hit the spot between heads, the truck developes a miss and then goes away. Starts good, runs good, no fluids interchang anywhere. Any recommendations here? Quote Link to comment Share on other sites More sharing options...
JoeH Posted March 20, 2019 Share Posted March 20, 2019 22 hours ago, LTR Diesel said: Hi guys. New to this site and in need of opinions. I have a 2001 Mack vision 460. I am told the engine is not original as it is a non electrictronic engine. I have fuel leaking from rocker box cover down between #4 #3 heads. When running, I sprayed Beale clean on block to clean it up and find the source of the leak. When I hit the spot between heads, the truck developes a miss and then goes away. Starts good, runs good, no fluids interchang anywhere. Any recommendations here? Yes. Start your own thread. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.