QUESTION:
We have a 2000 Ford F-350 with well over 400,000 miles. It has a standard transmission with a Masport pump. You have to push in the clutch, flip the switch, and then the pump engages as you let out the clutch. Now, if you let out the clutch, it sounds like the pump disengages and it makes a grinding noise. You have to quickly put the clutch back in and then let out again until it engages. Sometimes it will do this two to three times before the pump actually stays running. We have already changed out the clutch plate and the pressure plate. Do you have any suggestions on what the problem might be or how I can fix the problem? I am determined to keep this truck running over 500,000 miles!
J.D. & Jill Sutter
Sierra Vista, Ariz.
ANSWER:
You’re doing great getting 400,000 miles out of your truck. The problem in this instance is the power take-off. The PTO has a worm gear and a drive gear. When these gears are engaged, energy is sent to the pump. With more than 400,000 miles on the truck, these gears have engaged and disengaged how many times? They are most likely shot. That is why they engage only after several attempts at starting the pump. Best thing you can do is replace the PTO, but before you complain, remember that PTO made you a lot of money and ran for a long time before fading. Lots of people trade in the truck before their PTO is shot.
Basically what has happened is that the teeth on the worm and drive gears get worn down until they don’t line up properly. To replace the PTO, the transmission oil must first be drained because the PTO is hooked up to it. Pull off the old PTO and then install the new PTO. Make sure it is shimmed properly with gaskets, tighten it up and then pour new gear oil into the transmission. Don’t use the old gear oil. It is contaminated with the debris and shavings from the worn gears and bearings of the old PTO.
Let’s look at some costs. The PTO will likely run as much as $700, and most shops will take 4-5 hours in labor. Toss in some environmental fees and you are probably looking at a total job of around $1,100-$1,200. Is it going to be worth it to put that in the old truck? That is a call you have to make with the advice of your mechanic. PTOs typically last 5-6 years if properly maintained.
It’s tough to decide when cash flow is critical to every business. Spend $1,200 for a stopgap fix or obtain financing and go with a new truck? What if the truck breaks down in a month and you’re not making any money? There is no easy answer.
QUESTION:
I’m about to order a new truck. For a few bucks extra I can get a riser pipe installed. What is your opinion of riser pipes?
Gerald Denkins
Sioux City, S.D.
ANSWER:
The riser pipe is placed at about a 45-degree angle from the vacuum tank suction fitting, conveying waste upwards toward a high central area inside the tank. This allows for better distribution of the load as it comes into the tank. It also helps limit the amount of waste that can spill back out of the inlet when you remove the hose.
Over the years we’ve seen all types of riser pipes, but here’s what you really need to know: The vacuum operating inside the tank will work just as well with a riser pipe or without one. Some tank builders will suggest a riser pipe, while others won’t stress its importance. It is often considered an optional component and might add $50 to the cost of your tank.
If you have a riser pipe installed and angling upward inside the tank, do not allow the waste to simply project into the tank wall during loading. Day after day, the constant splatter of waste hitting the tank in one spot will lead to rust or corrosion and create a weak spot. There are two easy ways to combat this potential corrosion: One option is to add a wear plate to the portion of the inside tank wall where the waste enters. The other option is to add a 90-degree elbow to the end of the riser, which will direct the flow down into the tank from above.
Installing a riser pipe in a tank is a matter of personal preference. It helps distribute the waste, but your system will work as well without it.
