Cat D4H Fuel Leak - injector pump tach shaft

[RodC]

I'm working on a Cat D4H that has an unused tach shaft on the end of the injector pump, there is no cover. (3204 engine) I have seen a few posts mentioning a 1/16" plug for the vent on other Cat models, but no mention of this model with no cover.

I would replace the seal, but I bet the shaft is worn out.

Is there a cover available for this pump?

 

[Nige]

Could this be what you're looking for.?

 

[RodC]

Could this be what you're looking for.?

Yup, that's it exactly. I couldn't find a parts diagram with that on it.

 

[Welder Dave]

Really strange someone would remove that cover and not put it back on. Doesn't look impossible to get at or anything.

 

[Nige]

What’s to say it didn’t have a tachometer that someone removed in the past and did not fit the appropriate cover thus leaving the end of the shaft exposed.?

 

[Cmark]

Not sure it will do you much good. I think that cavity has a telltale hole. The best fix it to replace the seal. You're right, the shaft may need replacing but it can be done.

 

[Mobiltech]

Yes it will still leak out the bleed hole. The cover will sure look nice though!

 

[Welder Dave]

What’s to say it didn’t have a tachometer that someone removed in the past and did not fit the appropriate cover thus leaving the end of the shaft exposed.?

Could have had a tach at some time. Being where it is seems asking for trouble leaving the cover off.

 

[RodC]

Looking at some pics on the internet, there are several of these pumps out there without covers. (You can see paint on the pic I posted above) I spoke to a guy who owns 3 backhoes with injector pumps that look just like this, none of them have covers on them.

It appears that Cat is aware of the issue and even has a 1/6" plug available to seal up the weep hole. (3D4603 plug)

When I first posted I mentioned "I have seen a few posts mentioning a 1/16" plug for the vent on other Cat models"

Here are some references:
https://talk.newagtalk.com/forums/thread-view.asp?tid=691168
https://talk.newagtalk.com/forums/thread-view.asp?tid=521004

My local cat Dealer should have a cover tomorrow. I have installed the 1/16" plug. I will post back my results soon.

 

[RodC]

We installed the new cover yesterday. We had all the covers off and the oil lines to the turbo to change the exhaust manifold, made it much easier to reach. The new cover is plastic. The o-ring fits pretty snug, it is on a round portion that sits inside the opening.

 

[Welder Dave]

I guess plastic is better than nothing. Being from Cat was it any cheaper than if it was steel?

 

[RodC]

I guess plastic is better than nothing. Being from Cat was it any cheaper than if it was steel?

I had no clue it was going to be plastic. I just used the PN from above and this is what they sent, Cat dealer didn't mention any other options. It was only $4, prob the cheapest part I have bought for this machine.

 

[Welder Dave]

That's good the price was inline with what the part is made from. Finning up here wanted a couple bucks for the rubber ring/gasket that fits around the oil pressure gauge. The gauge didn't come with it and was almost $100. I bought an aftermarket gauge for much less and it came with the rubber gasket. The Cat gauge is better but I just wanted something to indicate I have oil pressure. The original gauge showed I had good oil pressure in the proper range but started leaking and making a mess on the dash and oil was running down behind the dash.

 

[RodC]

... leaking and making a mess on the dash and oil was running down behind the dash.

I keep envisioning guys with this fuel leak, that do have a tach, thinking they have a fluid filled gauge. (Off road diesel pink)