cav pump

[sam in mo]

Has anyone replaced the oring in a cav pump? The big one between the head and the main body of the pump. If so how hard was it to do ? Was thinking about tackleing the job myself. Need opions on the soundness of that thought. Thanks Sam

 

[Tony in Mass.]

you can scroll down here and the Harry F forum and find the posts I started about my standard diesel. this is a touchy subject. I did get into the back of mine lately, and might have to get in there again, I was suppose to get local 'housecall' help, he didn't show yet, if never, I will tear into the top. Just read thru the threads, see what you find that isn't sickening....

 

[Bill Brox]

Tony, maybe he got cold feet, the courage left him and that is why he does not show up. Or maybe he has just been busy.

Bill

 

[Bill Brox]

Some says you can get away with doing it yourself if you do not touch any adjusting things inside there.

I don't know.

Bill

 

[Tom-TX]

Sam, I am copying a long post from my files about replacing the o-rings around the throttle shaft and cut-off shaft, as well as the top gasket. You should replace all these as they will leak sooner or later. My advice is clean, clean, clean and write down and/or photo ALL springs/connections BEFORE unhooking them. Tom


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

 

[sam in mo]

Thanks for the replys. I've already replaced the O-rings that you describe. My leak is inside the pump where the head slips inside of the main part of the pump. There is a O-ring in there between them that is leaking.Was wondering if I could replace it without having to put it on a test bench and resetting everything. Thanks again for all the replys. Sam

 

[Tony in Mass.]

It seems like I give too much information too early Bill... or I don't lie enough. If I left out the word "English' or 'Standard' - and said nothing of the maker, or just said, CAV, or 'oh, a perkins, you know all masseys have perkins, yayaya'', THEN I would get co-operation.... yes, mechanics have cold feet due to a lack of cold beer?

 

[Bill Brox]

LOL, you think the beer will warm up their feet...

Not sure I would like to have a drunk mechanic tamper with my fuel injector pump.

How much do you have to pay for letting a diesel shop fix the pump for you ?

Here I would have to pay around $400-500 for such a job.
And, that would include all new gaskets, the pump tested and adjusted in bench.


Bill

 

[Tony in Mass.]

The shop closest to me wants $700 US, That's just too much. That might have to happen if I can't get the fuel the last stage up. We'll see.