Leaking Injector Pump

[Dynamo1181]

I remove the exhaust manifold as well.
A

[endoftheroad]

Other than the ugly sight of diesel fuel leaking at throttle arm.
When this leak is present, what effects does it have on the pumps performance?
Does the pump put out less pressure?

[osirissail]

Originally Posted by endoftheroad

Other than the ugly sight of diesel fuel leaking at throttle arm.
When this leak is present, what effects does it have on the pumps performance?
Does the pump put out less pressure?

I don't think the problem will be with lower pressure output to the injectors but instead, an accumulation and eventually a steady stream of diesel fuel into your engine compartment. What with both the price of diesel and the cost of the fines for when the bilge pump proceeds to pump it over the side - it is not something "you can live with." It needs to be fixed.

[Nemos]

Most recent update –

Got the governor seals replaced and the governor back on the injector pump. Bled the engine and IT RUNS! Bit it won’t idleL…

I must have damaged something in the injector pump.

New injector pump purchased from Transatlantic Diesel and I think I’m going to let the pro’s install it….

[cburger]

Nemos I am experincing the same issue with my Perkins, did the o rings take care of the problem?

[Nemos]

Yes, the o-rings stopped the leak from the governor. UNFORTUNATLEY – my attempt to do the work without removing the injector pump and doing the work on a bench left the pump damaged. It wouldn’t idle…

Things only got worse from there…

Ordered a replacement pump from TAD – they were great.

But because I was short on time, I hired one of the Bay area marine diesel mechanics to swap out the pump, and he made a complete mess of the job.

Finally took the boat into KKMI in Richmond, CA and now everything is working well.

[Dynamo1181]

Nemos,
Are you saying that all would have been well if you had removed the pump for the o ring repair first?
Thx
Alan

[Tia Bu]

I had the same problem with a Lucas CAV pump on a Volvo MD7A. I think this is basically the same pump, with a different number of outlet ports. I tried replacing the o-rings myself following the Internet instructions, but it didn't stop the leak. I finally had to take the pump off myself and send it to Blue Ridge Diesel in Virginia for a rebuild. They were quite reasonably priced, very helpful, and not at all condescending about my do-it-yourself efforts. In the end, they found that the rectangular cover had actually warped a bit, perhaps when I worked on it, and that was causing the additional leaking.

In hindsight, I think I should have pulled the pump off and shipped it to them for a rebuild first thing. The rebuild cost about half their originally estimated price, and the engine runs great now. If that throttle seal is leaking, the pump could probably use a thorough going-over by a pro anyway.

Pulling the pump off (and reinstalling it) was a scary-looking job for a novice, but it turned out not to be too difficult at all, at least on the Volvo. My engine and I are intimate acquaintances now :-) And if you can pull the pump and reinstall it yourself, the rebuild shouldn't break your bank.

[sdynes]

We also have a Perkins 4108 with a Lucas CAV injector pump (hydraulic governor, like that in Fig. N8 of Bleeding the Perking Diesel) that is leaking from the throttle shaft. It was manufactured in the early-mid '80s; we don't know how many hours it has.

Based on what I've read here, our choices are:
1) Attempt to replace the O-rings on the throttle spindle.
2) Get a rebuilt unit
3) Live with it

I don't think 3) is a long-term option. 1) is something we can do now, seems to have a success rate of less than 100%, and if the spindle O-rings are failing, others are probably failing as well, but I don't know this. 2) is something we would do at the end of the season, and is bigger bucks.

My question is, of the folks who've tried 2), how many have succeeded in just replacing the O-rings? Did other things fail in the next year that required you to replace the pump anyhow? And, did you have to remove the heat exchanger to accomplish this?

Thanks!

Scott

[svHyLyte]

Originally Posted by sdynes

We also have a Perkins 4108 with a Lucas CAV injector pump (hydraulic governor, like that in Fig. N8 of Bleeding the Perking Diesel) that is leaking from the throttle shaft. It was manufactured in the early-mid '80s; we don't know how many hours it has.

Based on what I've read here, our choices are:
1) Attempt to replace the O-rings on the throttle spindle.
2) Get a rebuilt unit
3) Live with it

I don't think 3) is a long-term option. 1) is something we can do now, seems to have a success rate of less than 100%, and if the spindle O-rings are failing, others are probably failing as well, but I don't know this. 2) is something we would do at the end of the season, and is bigger bucks.

My question is, of the folks who've tried 2), how many have succeeded in just replacing the O-rings? Did other things fail in the next year that required you to replace the pump anyhow? And, did you have to remove the heat exchanger to accomplish this?

Thanks!

Scott

Against the possibility that you do not realize it, you are dealing with quite an old thread.

Beyond the foregoing, having just gone through the brain damage and expense of an injection pump repair (last November), if the O-Rings on the throttle pump are going/gone, you'd be wise to do a complete rebuild. Assuming you have good access to the pump (rare!), it is not that difficult to remove save for a single inside lower bolt that requires a allen type hex wrench with a long extension. Take the pump to a good diesel shop and let them rebuild/test the thing for you. While you can go to a marine diesel facility, the Perkins is also used on lots of farm equipment and in the trucking industry and a good farm equipment or truck facility can handle the job and may be somewhat less costly. For what its worth, take a very close look at your high pressure injection lines and injectors before going to the trouble of reinstalling your pump. It may be wise to replace the injection lines, which are not that costly, and have the injectors cleaned and serviced so that your fuel system is fully restored when you reassemble it.

You will find an extensive discussion of the matter at: http://www.cruisersforum.com/forums/...ild-72807.html

FWIW...

[sdynes]

Thanks - I did know the thread was old, but it seemed like the right place to post. This is a new boat to us; we're spending significant effort on cleaning/renewing/etc. I tend to agree with you that the right thing to do is to rebuild the entire fuel system - pump/injectors/lift pump/fuel lines; we're looking for a reliable pain-free engine experience, and doing a half job isn;t the way to get there.

Thanks for the benefit of your experience.

Scott

[Bermuda Forte]

I too have a 4-108. This week, the fine local yard, Brick Cove, here in Southold NY, replaced the throttle linkage o-ring for me. After researching the issue thoroughly, including reading through these Forum threads. I'm usually one for DIY but this looked like a job for pros. I had arranged for them to remove the fuel injector pump and send it to TAD in VA (very good place). However, they were confident they could do it. It looks to work fine now after 7 hours labor + minor parts and fuel filters. I repowered from a Westerbeak 4-107 in 1986 and the motor has 1,135 hours. I do have a slowly leaking rear oil seal so at some point she's coming out for a proper rebuild. In the meantime, we're happily off cruising Eastern Long Island Sound, Block & the Vineyard.

[svHyLyte]

Originally Posted by Bermuda Forte

I too have a 4-108. This week, the fine local yard, Brick Cove, here in Southold NY, replaced the throttle linkage o-ring for me. After researching the issue thoroughly, including reading through these Forum threads. I'm usually one for DIY but this looked like a job for pros. I had arranged for them to remove the fuel injector pump and send it to TAD in VA (very good place). However, they were confident they could do it. It looks to work fine now after 7 hours labor + minor parts and fuel filters. I repowered from a Westerbeak 4-107 in 1986 and the motor has 1,135 hours. I do have a slowly leaking rear oil seal so at some point she's coming out for a proper rebuild. In the meantime, we're happily off cruising Eastern Long Island Sound, Block & the Vineyard.

There's good news and bad news. The good news is that you seem to have managed an inexpensive pump rebuid without difficulty. The bad news is that a rebuild of your engine to cure the seeping rear seal will not (for long) eliminate the seepage. It seems to be a characteristic of the 4-108. One thing that will help is redoing the airfilter system. A KN filter with a line to your crankcase vent will reduce the crankcase pressure and so the seepage from your real seal--but not completely.

FWIW...

[Bermuda Forte]

Thanks for the tip on the leaking rear oil seal. So far it's not too bad. I'm wondering, do I just live with it? Or, is there a serious failure mode I should be concerned about? Can you tell me what a "KN filter" is exactly?

Best

Capt'n Q

[oepi-loepi]

Well, i have just finished the same job with some help of this forum. Also i have a Perkins 4.108 diesel engine (marine version) and the throttle shaft is leaking. (in dutch for who is interested: cav pomp lekt diesel uit de gashendel).

Solution:
1. close the fuel line
2. remove the oil filter (this has to be removed anyway). clean the area and put some cloth on the open end of the filter housing.
3. mark the throttle wheel and remove the spring and wheel (leave the cable on)
4. measure the hight of the bolt for minimum throttle and remove it.
5. remove the 1/4 SAE 12-point bolt on the throttle end which holds the housing.
6. pull the throttle shaft out of the housing
7. replace the o-ring, ad some vaseline (only on the o-ring)
8. push the shaft back in by some force
9. screw in the 12-point 1/4" bolt which holds the housing
10. reinstall the throttle wheel and spring
11. screw in the minimum throttle bold to the earlier measured height.
12. open the fual line
13. open the most top bolt on the governor housing and manually pump diesel till diesel comes out this vent. Close the bolt.
14. reinstall the filter.
15. slacken 2 of the injectors fual lines
16. start-start-start-start the engine till diesel comes out the injector lines. Tighten them and do the same for the 2 other lines.
17. Engine must run now without leakage.

(in dutch for who is interested and to help my dutch friends using google: cav DPA hydraulische pomp van Perkins 4.108 lekt diesel uit de gashendel of gashendel as).

Goodluck with this simple repair (if you know it's simple.....).