1998 Dump

[Sgt C DUB]

I have a 1998 mack dump, just got the truck and don't know much about it. The truck will shut down while driving. The first time it happened I filled the coolant and it didn't happen for a while. Now its back to haunt me. the coolant is and was full. The sensor works, I had it plugged in and the shutdown light was off, unplugged the sensor and it came on as expected. What ells should i look for that will shut it down? oil PSI at idle is 60. and for some reason the jake wont work but at low RPMS.

[counterman6]

Maybe a fault in the ECM?

[Sgt C DUB]

Maybe a fault in the ECM?

After a brief ovbservation I noticed that the EML was not coming on and its supposed to on start up. Its also the light for the flash codes so no flash codes. So i have to figure that out too. I have no manuals. It running blind.

Thank you for your response!

[counterman6]

Just chatting with the shop foreman and he mentioned an update done to the Jake system in that era that provided the Jake with additional oil to prevent low oil PSI shut-downs and high RPM Jake malfuntions. Are there oil lines (braided steel)feeding through the Jake spacers?

[Sgt C DUB]

Just chatting with the shop foreman and he mentioned an update done to the Jake system in that era that provided the Jake with additional oil to prevent low oil PSI shut-downs and high RPM Jake malfuntions. Are there oil lines (braided steel)feeding through the Jake spacers?

Yes, the update was performed because the jake was not working. When the truck came back from the dealer the jake was performing the same. The update didn't seem to work. The lines are not braided steel. They are a pressure fabric hose with a steel braid inlay. not sure if that makes a difference.

The truck was just driven and the driver told me it didn't shut down unloaded. When it was loaded is when it happened. Also it seemed to do it more while he was into the throttle. The first time the truck died it correctd it self. the seconded time he had to turn the key off then back on while rolling in gear. After that he made it back to the shop.

Thanks again for the help!!

[Sgt C DUB]

Just chatting with the shop foreman and he mentioned an update done to the Jake system in that era that provided the Jake with additional oil to prevent low oil PSI shut-downs and high RPM Jake malfuntions. Are there oil lines (braided steel)feeding through the Jake spacers?

Yes, the update was performed because the jake was not working. When the truck came back from the dealer the jake was performing the same. The update didn't seem to work. The lines are not braided steel. They are a pressure fabric hose with a steel braid inlay. not sure if that makes a difference.

The truck was just driven and the driver told me it didn't shut down unloaded. When it was loaded is when it happened. Also it seemed to do it more while he was into the throttle. The first time the truck died it correctd it self. the seconded time he had to turn the key off then back on while rolling in gear. After that he made it back to the shop.

Thanks again for the help!!

[counterman6]

Asking around, the guys asked if the speedometer is working correctly (speed sensor bad),maybe a faulty oil pressure switch to the computer (cycling the key would reset it and allow the engine to fire up)and a bad ABS module may account for the EML not working properly.

A head scratcher for sure, good luck!

[Sgt C DUB]

Asking around, the guys asked if the speedometer is working correctly (speed sensor bad),maybe a faulty oil pressure switch to the computer (cycling the key would reset it and allow the engine to fire up)and a bad ABS module may account for the EML not working properly.

A head scratcher for sure, good luck!

I really thank you for your time.

one last thing did the update also have the turbo line tee'ed into the lines for the jake?

[rhasler]

The first thing I would find out is why the EML isn't coming on when the key is turned on. Being a used 1998 RD there is a high likelyhood that the bulb is either burnt out or missing. Remove the dash panel with the speedometer and tachometer and trace the bulb down. It should be a standard 194 bulb.

The VMAC III engine can be set to shutdown for low coolant level, high coolant temperature, low oil pressure, high oil temperature, high transmission temperature, and high pyrometer temperature. Based on the conditions you described I would look toward the temperature readings. If you get the EML working you should be able to flash a blink code out, which save a lot of searching for a problem.

The oil supply for the turbo will come off of the top of the oil filter housing just beneath the intake manifold with a bundle type oil cooler, and off of the top rear side of the filter housing for an engine with the plate type oil cooler. On the plate type oil cooler setup the exxternal ol lines to the engine brake are tee'd off of the same fitting supplying the turbo.

[Sgt C DUB]

The first thing I would find out is why the EML isn't coming on when the key is turned on. Being a used 1998 RD there is a high likelyhood that the bulb is either burnt out or missing. Remove the dash panel with the speedometer and tachometer and trace the bulb down. It should be a standard 194 bulb.

The VMAC III engine can be set to shutdown for low coolant level, high coolant temperature, low oil pressure, high oil temperature, high transmission temperature, and high pyrometer temperature. Based on the conditions you described I would look toward the temperature readings. If you get the EML working you should be able to flash a blink code out, which save a lot of searching for a problem.

The oil supply for the turbo will come off of the top of the oil filter housing just beneath the intake manifold with a bundle type oil cooler, and off of the top rear side of the filter housing for an engine with the plate type oil cooler. On the plate type oil cooler setup the exxternal ol lines to the engine brake are tee'd off of the same fitting supplying the turbo.

Thank you for your response!!!

The bulb for the EML was in the wrong socket. The light now works and doesn't have any codes. We removed the line from the turbo curcit that feed the jake and gave it its own line. The jake works well!! Impressive! As for the stalling we are not sure if its was one in the same problem. so a test drive today will tell us. We did notice that the shut down light came on at or about 1800 to 2000 rpms and shut back off at 1500 rpms. The truck wouldn't shut down but i could get the light to stay on. not sure why rpms would influence the light.

Thank you for your time.

[counterman6]

So was the Jake update performed incorrectly or not to factory specs?

Glad you got it working!

[Sgt C DUB]

So was the Jake update performed incorrectly or not to factory specs?

Glad you got it working!

Not sure but the truck doesn't shut down any more.

I think we're good.

Thank you everyone for your help!!

[rhasler]

The early E-Tech engine rocker shafts had an expansion plug in each end to seal in the oil used to lube the valve train and supply oil to the Jake Brake. It is not uncommon for the expansion plugs to blow out of the shafts (usually the front plug on the front rocker shaft in my eperience) resulting in low oil pressure to the valve train and Jake Brake.