# Ford 400 Fuel Pump leak



## chriscope (Jul 26, 2015)

Hello all
I have a 71 Ford 4000 in the UK. Last month it developed a leak from the top of the fuel pump at the pump control lever (as pointed at in the photo). Having found a diagram on the net, it looks like the spindle has two rubber rings.
If it is the top rubber ring that is leaking then I can probably replace it without pulling the pump apart (not something that I am keen to do as I hear there are several things in there which can pop out - so great care required).
Not done this before and wanted anyone's opinion about whether I am wrong or any other advice. I will keep things very clean when doing it.
Interestingly, a couple of my Dad's 5600s have just developed some diesel leaks. Maybe a coincidence, because they are all getting older, but makes me wonder about the diesel.
Thanks!!
Chris


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## HarveyW (Sep 15, 2014)

Hello chriscope,

Welcome to the Ford/New Holland tractor forum.

Unfortunately, you have to pull the top cover to replace the throttle shaft seals. I copied the following old post written by *Tom-NorthCenTX* on the internet:
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"There are indeed small springs under the top cover. And, each one has to be hooked EXACTLY in the same hole or the tractor will never run right again. Also, replace the small O-rings around the throttle shaft and the cut-off shaft, because they will eventually dry out and leak. Don't tight-wad about the gasket buy a new one, as it is very thin and must seal with minimum pressure. The long quote below is from previous posts about the CAV pumps, so ignore the parts non-applicable. Tom

The CAV pump 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 bit 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 Ford/New Holland 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 Ford/New Holland 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."


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## BigT (Sep 15, 2014)

Attached are two CAV manuals I've taken from the internet.


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## chriscope (Jul 26, 2015)

Hi Harvey
Really good PDFs. Cheers!
Chris


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