DIY Injection Pump Rebuild

[S/V_Surya]

Has anybody ever successfully rebuilt an injector pump or injectors themselves? I know they sell kits and that a proper rebuild takes some special equipment. I am going to have to do it for my Perkins 4108 IP and will do injectors at same time to be on the safe side. What are the risks?
Thanks....
Rich

[Celestialsailor]

I hear the injectors themselves are not too bad if you're a Machinist and need to be re-machined. The pump however I have been told has to go to a shop.

[bobconnie]

Injectors. need to be tested for flow,pattern,amount, ect. If you do them they should go to a shop to be tested! if there messed up you will still pay for the test and still have a mess that needs fixing! if they bild them they test and fix if nessasary. Ive re-bilt and tested a lot of injectors over the years, and I would not touch them without a test bench availible! And I would sure as heck send the Injector Pump to a GOOD shop for rebilding !! and mark it before you remove it LOL just a old guys thoughts from many mistakes made over trying to save money and costing myself a bunch more messing up Bob and Connie

[Charlie]

I just did the injectors on my Mercedes diesel. Here is a link. It really wasn't very hard don't know about Perkins. The hardest part was the tool needed to Pop test the injectors. I managed to buy the injector nozzles and the pop tester and shims for less then the cost of rebuilt injectors. It took me awhile but I had fun learning how to do it. Car runs much better now. http://www.cruisersforum.com/forums/...ors-72057.html

[Celestialsailor]

Yup...The shop that rebuilt my engine let me use his home made pump with gauge to pop test my injectors. It used Kerosene for the test. Let's face it, this kind of stuff isn't meant for everyone but it's not black magic either. Almost everyone I know that "had" to take their injectors to a shop, some how needed all new injectors. What do you think sailors did before internet while they were in remote areas while cruising?

[colemj]

DIY injector rebuilding is one thing, but the OP asked about rebuilding his own injector PUMP. This is a much more difficult job that requires a squeaky clean room and some specialized equipment. It must be possible to DIY, but personally I wouldn't.

If you mess up an injector, you are out a hundred or so - if you mess up a pump, you are out thousands.

And we had injectors rebuilt in Baltimore last year for $65/each, including new crush washers. Not a bad price for a simple drop off/pick up next day thing, and maybe less expensive than doing it yourself.

Mark

[Charlie]

Originally Posted by colemj

DIY injector rebuilding is one thing, but the OP asked about rebuilding his own injector PUMP. This is a much more difficult job that requires a squeaky clean room and some specialized equipment. It must be possible to DIY, but personally I wouldn't.

If you mess up an injector, you are out a hundred or so - if you mess up a pump, you are out thousands.

And we had injectors rebuilt in Baltimore last year for $65/each, including new crush washers. Not a bad price for a simple drop off/pick up next day thing, and maybe less expensive than doing it yourself.

Mark

In California the price is $75 or better so for the six I needed it was $450 plus tax and shipping./ I bought the pop tester shims and the rebuild kits for under $375 and now I can test the injectors on my boat and on my tractor.

Originally Posted by S/V_Surya

Has anybody ever successfully rebuilt an injector pump or injectors themselves? I know they sell kits and that a proper rebuild takes some special equipment. I am going to have to do it for my Perkins 4108 IP and will do injectors at same time to be on the safe side. What are the risks?
Thanks....
Rich

He asked for both.

[Celestialsailor]

He asked about the injectors also and that is what I commented on, not the pump

[S/V_Surya]

Thanks for the opinions. Engine runs good but getting diesel fuel into crank case which could be the pump or injectors. So come spring I will send them out for rebuild.
Thanks Again

[colemj]

Originally Posted by S/V_Surya

Thanks for the opinions. Engine runs good but getting diesel fuel into crank case which could be the pump or injectors. So come spring I will send them out for rebuild.
Thanks Again

Have you check the fuel lift pump diaphragm?

Mark

[delmarrey]

It'll take good mechanical skills, cleanliness and the proper tools.

There are tolerances that need to be held and specialized cleaning systems. And w/o the proper tools and facilities it would just be trial & error.
As a Machinist and not having done a pump or injectors myself I'd take it to the experts, even though I have the skills/knowledge. Injector shops specialize because it's more then just a twist of a wrench. Would you go to a General Practician to get dental work done?

There are some online instructions these days where if one really wanted to, they could learn pretty quick, I'm sure. But I look at how much in tooling and time I would need to invest B4 getting expert results.
It would be good knowledge to have out on the water but I don't think I would want to pull a pump apart except in a survival situation. Prevention is more important IMHO.
Even as a Machinist I cater to specialists. HVOF, heat treaters, tool & cutter grinders, water & laser cutters, platers, instruments calibrators & etc. all because they have the tooling/facilities.

Like myself, one can have the knowledge to build jet aircraft but w/o the tools/facilities, that's all it is!

[S/V_Surya]

Concerning the lift pump.... Yes, I bought a new one and also checked the old one. The diaphragm was fine.

[svHyLyte]

Originally Posted by S/V_Surya

Has anybody ever successfully rebuilt an injector pump or injectors themselves? I know they sell kits and that a proper rebuild takes some special equipment. I am going to have to do it for my Perkins 4108 IP and will do injectors at same time to be on the safe side. What are the risks?
Thanks....
Rich

One could probably do one's own Injection Pump. One could also probably do one's own Appendectomy. There are times, however, when it is wise to rely on a specialist who has the proper tools, equipment and knowledge.

In the case of the IP, considering the amount of work involved in simply extracting and remounting the pump, the possibility of having to do it twice due to an error in the rebuild, and then likely having to have a specialist rebuild the pump anyway, doing it oneself seems like a bad idea, no?

We are going through this now with a 4-108 pump that I just delivered to Southeast Power yesterday afternoon. They are rebuilding and testing the pump at a cost of approximately $650.00 USD of which roughly half is in parts. We have a bit over 3500 hours on the engine. FWIW I am also changing out the lift pump as well as, based upon 3 other boats in out little marina of 52, the 4-108 lift pumps all seem to expire within a few months of the pump beginning to leak. It might be worth considering as well. In theory one can rebuild the lift pumps but the diaphram and check-valve kits are evidently becoming difficult to find at this point and I don't want to take any chances given the effort that's going into this process.

FWIW...

[Celestialsailor]

If i might add to the lift pump failing...This was a reoccuring problem I had on a few of my boats. The solution I finally came up with was a "day tank" mounted as high or higher than the engine of 20 gallons. The main tanks in the boat (usually in the lower bilge or keel) became storage tank(s). Fuel was transferred with an electrical fuel pump (cost $35). This had a few benefits. 1) lower load on the lift pump. 2) If fuel was contaminated, I had many more options.

[Astrid]

This might give an idea of what is involved in the injector pump rebuild, however the author states:

Note: This article does not explain how to replace the shaft bearing or how to set internal pressure. It is only a cleanup and resealing guide.

Bosch diesel injection pump rebuild