Change that pump oil!

[Bern]

A customer with a 6600 with a CAV inline injection pump called me today telling me that the RPMs are all over the place. Sounds like a governor problem over the phone. I go out there and sure enough, there is little to no control over the engine speed using the throttle lever. I begin to pull the pump off by removing the front cover to align the timing marks. I find the stationary mark to be wiped out, so I immediately knew the bearings were shot which allowed the drive gear to machine the hash mark away.

I removed the pump and found that the cam had nearly .200" of end play. Sure enough, one of the cam bearings is near failure. Everything else looked OK, so I'll put it back together with new bearings and seals, along with new plunger return springs, which are prone to breaking. I will also spill time the pump on the bench to make a new timing mark.

Turns out the customer hadn't changed the pump oil in years. His reason? One of the fill/drain plugs was stripped out and he didn't dare mess with it as it was not leaking. Yep, it wasn't leaking alright! There was hardly any oil left in the pump. So, while I wait for parts I heli-coiled both fill and drain plug holes as well.

So, in summary, if you have an inline pump, be sure to check and change your oil (except TW and late 4-cylinder engines), and don't overtighten the fill/drain plugs.

 

[Welding man]

I tell my customers to change that oil every time they change their engine oil and show them how to do it. Most of them say they didn't know or never were told it needed to be changed.

 

[Fordfarmer]

I tell my customers to change that oil every time they change their engine oil and show them how to do it. Most of them say they didn't know or never were told it needed to be changed.

It's amazing how many people have never read even part of the owners manuals, after spending thousands of dollars to buy their tractors and equipment.

 

[Dieseltech]

Yup I see a lot in that shape too. For the timing mark the spec is 2.9-3.1 MM lift on the front tappet, I make sure the marks align at 3.0 then adjust tappet spacers as needed as per instructed at service training years ago. When new those pumps SHOULD have Heli-Coil inserts installed like Bosch does on their pump housings as I've NEVER had to repair a Bosch housing yet do to thread damage, can't say that on Simms/CAV pumps. I am surprised pump didn't need a governor weight kit, the skate wheel set was not the best design. The latest C type governor works much better, but does have cushion wear issues too though.

 

[Fred Werring]

A customer with a 6600 with a CAV inline injection pump called me today telling me that the RPMs are all over the place. Sounds like a governor problem over the phone. I go out there and sure enough, there is little to no control over the engine speed using the throttle lever. I begin to pull the pump off by removing the front cover to align the timing marks. I find the stationary mark to be wiped out, so I immediately knew the bearings were shot which allowed the drive gear to machine the hash mark away.

I removed the pump and found that the cam had nearly .200" of end play. Sure enough, one of the cam bearings is near failure. Everything else looked OK, so I'll put it back together with new bearings and seals, along with new plunger return springs, which are prone to breaking. I will also spill time the pump on the bench to make a new timing mark.

Turns out the customer hadn't changed the pump oil in years. His reason? One of the fill/drain plugs was stripped out and he didn't dare mess with it as it was not leaking. Yep, it wasn't leaking alright! There was hardly any oil left in the pump. So, while I wait for parts I heli-coiled both fill and drain plug holes as well.

So, in summary, if you have an inline pump, be sure to check and change your oil (except TW and late 4-cylinder engines), and don't overtighten the fill/drain plugs.

Bought an 8700 from a buddy of mine. He happened to be in my shop while I was changing oil. Asked what I was doing when I drained the oil from the pump. Said he didn't know anything about that. He had a couple other Fords with inline pumps that were gonna get their oil changed when he got home.

And I started using dowty washers on my drain/fill plugs. Don't have to snug them up quite as tight as aluminum or copper washers, been working for me.

 

[Fritz Maurer]

So what is done about the timing mark? How do you time it?

 

[Bern]

Yup I see a lot in that shape too. For the timing mark the spec is 2.9-3.1 MM lift on the front tappet, I make sure the marks align at 3.0 then adjust tappet spacers as needed as per instructed at service training years ago. When new those pumps SHOULD have Heli-Coil inserts installed like Bosch does on their pump housings as I've NEVER had to repair a Bosch housing yet do to thread damage, can't say that on Simms/CAV pumps. I am surprised pump didn't need a governor weight kit, the skate wheel set was not the best design. The latest C type governor works much better, but does have cushion wear issues too though.

I won't bother with any measurements, as I am not disturbing anything that would affect the timing between the pumping elements. In other words, I'm simply keeping the tappets and rollers with their respective plungers. I don't disturb the rack or max fuel adjustments either, which keeps me from needing to put it on a pump stand, even though I do have access to one. Once I have the pump all back together on the bench, I will remove #1 delivery valve and spill time it for port closure with two PSI of air. I will then make a new chisel mark on the pump cover.

As for the heli-colis, you're right, I have noticed that Bosch installs them from factory. Simms/CAV was too cheap to do that, so it's been my experience that about half of the pumps I lay my hands on have one or more stripped plug threads. I always cross my fingers whenever I have to tighten one of those plugs.

There is very minor wear on the governor weight pad, but nothing to get excited over. It's a 50-year old tractor, so the owner is not expecting perfection, just something that works better than he had before.

The original bearings were of the ball type. Are they superseded over to tapered rollers now?

 

[Bern]

So what is done about the timing mark? How do you time it?

Once I have the pump all back together on the bench, I will remove #1 delivery valve and spill time it for port closure with two PSI of air. I will then make a new chisel mark on the pump cover.

 

[Dieseltech]

I won't bother with any measurements, as I am not disturbing anything that would affect the timing between the pumping elements. In other words, I'm simply keeping the tappets and rollers with their respective plungers. I don't disturb the rack or max fuel adjustments either, which keeps me from needing to put it on a pump stand, even though I do have access to one. Once I have the pump all back together on the bench, I will remove #1 delivery valve and spill time it for port closure with a two PSI of air. I will then make a new chisel mark on the pump cover.

As for the heli-colis, you're right, I have noticed that Bosch installs them from factory. Simms/CAV was too cheap to do that, so it's been my experience that about half of the pumps I lay my hands on have one or more stripped plug threads. I always cross my fingers whenever I have to tighten one of those plugs.

There is very minor wear on the governor weight pad, but nothing to get excited over. It's a 50-year old tractor, so the owner is not expecting perfection, just something that works better than he had before.

The original bearings were of the ball type. Are they superseded over to tapered rollers now?

The original 20084 ball cam bearing can be replaced by the 503742 tapered bearing now. The First MF/Perkins P5101 pumps used the ball bearing that would sometimes fail. The later Perkins used the P 5218 eight cylinder pump that came with the heavier tapered bearings. I use divider baskets for injection pump service to keep the parts separate too, but during assembly with the pump block off is when I measure the 3.0 MM cam lift and check the timing marks.
The last Ford/Simms I had in was really wrecked on the side oil level plug, housing had a quarter sized hole in the side when the owner installed a LONGER bolt, not thinking about the weight assembly lack of clearance inside the hole opening. First crank of engine ripped the bolt out of the side. Good thing I have a well trained welding guy close by, he welded up the housing to save it, and some mill work got it repaired again.

 

[Keith Williams]

Bought an 8700 from a buddy of mine. He happened to be in my shop while I was changing oil. Asked what I was doing when I drained the oil from the pump. Said he didn't know anything about that. He had a couple other Fords with inline pumps that were gonna get their oil changed when he got home.

And I started using dowty washers on my drain/fill plugs. Don't have to snug them up quite as tight as aluminum or copper washers, been working for me.

View attachment 81432

I actually used a washer for a garden hose on the top fill bolt.
Really gentle tightening the level and drain bolt.
That was on a 7200 With Simms.

 

[Bern]

Once I have the pump all back together on the bench, I will remove #1 delivery valve and spill time it for port closure with two PSI of air. I will then make a new chisel mark on the pump cover.

Some of you asked how I was going to make a new timing mark. The attached pic shows me doing this operation. It involves a very sensitive air regulator set at 2 PSI and an old injection line with a rubber hose going to a jar of water. I slowly turn the pump in the normal direction of rotation until I get to about 1 bubble per second. This is port closure or beginning of delivery. I then made a new chisel mark on the pump cover. Recall that the old one was wiped out when the bearing went out.

This same method can be used to confirm the accuracy of the existing marks. These might be suspect if there was internal wear in the pump. This of course can also be done on the engine. Let me know if you'd like more details.

 

[Dieseltech]

Some of you asked how I was going to make a new timing mark. The attached pic shows me doing this operation. It involves a very sensitive air regulator set at 2 PSI and an old injection line with a rubber hose going to a jar of water. I slowly turn the pump in the normal direction of rotation until I get to about 1 bubble per second. This is port closure or beginning of delivery. I then made a new chisel mark on the pump cover. Recall that the old one was wiped out when the bearing went out.

This same method can be used to confirm the accuracy of the existing marks. These might be suspect if there was internal wear in the pump. This of course can also be done on the engine. Let me know if you'd like more details.

The service school method was using the test stand using calibration oil at five PSI to do the same thing. Making the mark at 3.0 MM lift would have worked fine too long as there was no wear on the cam, tappet roller, or plunger/barrel wear.
Another option is to use the high pressure phasing system that most later injection pump test stands have, the delivery valve does not need removed using this method. Mack truck engines used to do this a lot with a high pressure field pump most Mack shops had.

 

[Bern]

The service school method was using the test stand using calibration oil at five PSI to do the same thing. Making the mark at 3.0 MM lift would have worked fine too long as there was no wear on the cam, tappet roller, or plunger/barrel wear.
Another option is to use the high pressure phasing system that most later injection pump test stands have, the delivery valve does not need removed using this method. Mack truck engines used to do this a lot with a high pressure field pump most Mack shops had.

I use air instead of fuel because it's less messy. That said, I discovered that the air pressure must be very low or else I can't get the bubbles to stop. I have to use that fancy regulator because a typical shop air regulator doesn't do well in the 2-ish PSI category. Just when you think it's low enough to get an accurate cut off, you find that it stopped flowing air period.

I do have access to a test stand that I could do high-pressure phasing with, however it permanently has a Bosch P pump on it that I use for demo purposes whenever I teach fuel systems. It's not much work to remove the delivery valve, as long as you have the right socket.

As far as the 3MM lift spec, you're right, it assumes no internal wear, which is a naïve assumption for me to make on a pump that old. I consider spill timing to be about as accurate as you can get.

 

[paul]

Doesn’t fuel often leak into this compartment and thin out the oil to where it might look full but it’s more fuel than oil?

Try to keep up with the 7700 on changing that oil when I do engine oil.

Paul

 

[Bern]

Doesn’t fuel often leak into this compartment and thin out the oil to where it might look full but it’s more fuel than oil?

Try to keep up with the 7700 on changing that oil when I do engine oil.

Paul

This happens with older pumps that have a lot of hours on them. That said, having a cambox full of diesel fuel is better than nothing at all.