Very Low fuel pressure

[DianeD]

Still have Low fuel pressure on our 6U D-4 Dozer.Has new filters.Has flow to the pump, and already had it running once, so we assume maybe it could be the transfer pump relief valve & spring.Does anyone know the price for one of these and where to purchase this assembly? Thanks!

 

[Anonymous-0]

You can get the valve and new spring from Cat. They aren't much money, don't remember exactly how much. Also be prepared to dress up the valve seat if need be. Usually resurfacing on a flat plate with a sheet of emery paper will do the job. When/if it becomes necessary to get an all new pump they are somewhat hard to find and pricey. Even the rebults if you can find them are costly. Post back if you need one. I know of at least one source for new and one for rebuilt. You will need to be sitting down when you get the price. There is also the used route...but.

 

[Anonymous-0]

I should have 2 transfert fuel pump for d4

 

[DianeD]

Will it fit a 1953 Model 6U7422 D-4, and how much do you want for one? Thanks

 

[DianeD]

I found someone that has a CAT transfer pump on Ebay. The part number is a 231-3947 .The guy says the pump fits a variety of Cat engines the most popular being the 3406,but it is just outdated by Cat standards. Would this fit a 1953 6U7422 D-4 Dozer? Thanks for your help!

 

[Anonymous-0]

I would say no, it will not fit. You need a unit from a D4 or D6, "U" model.
Most recent fuel transfer pump group is a Cat #5F6607 or a part #8M9758 but I don't have access to the latest interchange numbers.

The relief valve plunger and spring you were asking about is a 6B8917 plunger and 6B6663 spring.

Also if the clearance between gears and covers in the pump is .0035 in. or more it is considered worn out. When new they run about .001 - .002

 

[caterpillar guy]

Diane the transfer pump off of a 3406 is completely different than yours I've changed the pump on the 3406 and the pump you have is a little gear unit on the side of the engine much bigger and bulkier than the 3406.

 

[DianeD]

Well, we are really not sure it is the pump. I guess he is going to try to find the pressure relief valve and spring and try that first. Thanks