New Diesel Fuel and Injector Pump Leaks

Both of the pumps are on Perkins diesels in Massey Ferguson tractors. Both were leaking around the main body on the back side of the pump. Since you have to pretty much disassemble the pump to put new seals in I am leaving the repairs to the professionals.

According to the injector pump shop the problems were caused by the new low sulphur diesel. I haven"t been using any additives. Before the failures, I had several other leaks on both tractors in various spots on the fuel lines that had never been problems before.

Is your pump a CAV? If it is a CAV, I have been there done that. The CAV is prone to leaking around the throttle shaft and the cut-off shaft. First you will need to get 2 or 3 cans of engine cleaner. Clean, clean, and clean again the whole area. After each spraying, hose off, let dry and do it again. Cleaner the better, if you drop a ball of grease/dirt into the top while the cover is off - big trouble, one piece of crud dropped into the bottom of the pump will cost you about $600-700. Now using a paper towel, start looking for your leak; it will show up real easy on the dry, clean paper towel. 1. MOST important thing is to have some paper and pencil BEFORE you take off the cover.
2. Remove shut-off linkage and throttle linkage. 3. Remove screws or nuts holding lid on. 4. DO NOT just lift up the top. Lift it just a little, very carefully so you can peek under it. A spring is attached from the lid to the bottom part of the pump. One end of spring is hooked on a wide post looking like a tombstone. The tombstone has several holes in it. Write down which hole the spring is hooked in before you remove it. The other end is through one of the holes in the flattened end of the control rod. Again write down the hole it is in before you remove it. This step is VERY IMPORTANT. If the spring is not reassembled to EXACTLY the same holes on both ends, the tractor will never run right again. The same pump can be used on different model tractors with the only difference being how the spring is hooked. My MF dealer mechanic can tell the proper holes by using the 3 numbers on the CAV. Now remove the spring, and lift off the lid. 5. Write down the model/year of tractor, and the model of the CAV pump and serial number. There are 3 different numbers on my CAV pump.
6. Take the cover with you and head to MF dealer and purchase a new gasket and four (4) tiny o-rings that fit around the throttle shaft and the shut-off shaft. Each shaft has 2 o-rings. If the o-rings are not leaking now, they soon will so replace all of them. Total cost of gasket and 4 o-rings is about $5 or $6. 7. You will need a little patience and two extra hands to get the spring attached on both ends and the new gasket fitted. I did this complete procedure on my MF 690 and now it has NO LEAKS.
Tom

Rod

With bio-fuel, even B50 and less, there are consistent problems with rubber parts having to be updated to better materials to prevent leaks - including fuel hoses outside the pump.

I've got a combine pump doing the same thing.

It's never had the low sulfer stuff; it's 30 years old and is to be expected.

AGCO wants $200 to reseal 'er and put in a new governor ring.

Allan

If you need a governor dampening ring - I suppose you've got a Roosamaster/Stanadyne rotary on an Allis or IH? $35-$75 in parts and an hour's work on the bench for the right person - which makes the $200 price sound pretty good. You can also upgrade to an EID dampener that will never come apart again for an extra $45.

I don't believe the story about low-sulfur causing the problem. I also doubt pump shop people know the cause. They can suspect certain things, hear rumors, read conflicting service bulletins - just like anybody else. I worked in a pump shop back in the late 70s when Stanadyne pumps were failing often in GM diesels. I heard an awful lot of possible reasons given - by General Motors, Standyne Corp., etc. The truth is - a guy in the pump shop does not necessarily know more than anybody else as to what causes a problem in a pump unless it is overt.

This I do know. Now that ultra-low sulfur diesel is " hydro-cooked" to get the sulfur out - many additives are put in to bring the lube-quality up afterwards. It is possible that some of those additives are the "straw that breaks the camel's back" with older o-rings and seals. This also happens with bio-fuel - very often. Even eats up old fuel lines.

In regard to your CAV pumps? If they are rotaries, and they are leaking at the back of the pump - they do NOT have to come off the tractor. It's a 15 minute fix. On the back is an end-cap that's held on by four screws or small bolts. It is the regulator and wear-plate for a low-pressure, vane fuel pump in the pump. All that needs to be done - is you take the scews off, pull the cap off, put a new o-ring in, and put back together. Easy to do - no adjustments get changed. We had many brand new John Deere tractors - especially the 2940s - that we had to pull those plates off and fix before they even got sold. Now - if the leak is somewhere else? Different story.

In my area all you can get is ULSD, farm dyed, road, furnace oil. My supplier says the tank farms don't want to have seperate systems and tanks for USLD and non ULSD. Simpler to just have everything USLD.

Here in New York - we now have three fuels. Home heating oil is the same as ever - just cannot be sold for farm/off road anymore and is still red.

Farm and off road is a new color and is medium sulfur - not high and not low.

Then - there's road fuel - everyone knows about that rip-off. It was supposed to cost 10 cents more per gallon to produce. And, has 2-4% less BTU energy than the old diesel.

It's in the pipes and all ya can get anymore.

Allan

I am curious now how old are your tractors? I am wondering if we will have the same problems in the future or if in the new tractors it has been corrected.