Perkins 4.108 Leaking Throttle on CAV DPS

[AirApparent 1]

Our Perkins 4.108 has a CAV DPS fuel injection pump that is leaking 1 drop per 5 to 12 seconds from the bottom of the throttle lever. It continues to leak after shutting the engine off. Checked all the fuel lines and none are leaking, so we think it is an o ring or something on the throttle shaft. Does anyone have a parts manual or repair manual that would show us how to fix this?. I'd like not to remove the entire pump if possible.

[boatrips]

AirApparent 1:

My past experience with this engine was that we had to remove the diesel fuel pump and have it rebuilt.

We had quite a job removing it because of the placement of the engine in the boat, but with a little patience it came off quite nicely.

We took it to the local people who rebuild injectors and they gave us a price on rebuilding it. Alternativley they gave us a price on a rebuilt pump they alraady had in stock at about the same price, so we bought it and kept ours as a spare, just in case we had another problem later.

Good News: Fortunately, we've never had to use the "spare" in 10 years since that incident.

By the way: It really wasn't that hard to remove the pump or to replace it and the 4-108 is a great engine.

Good Luck,

Jim

[Pappy]

I tried to attach a perkins shop manual but the file s too large; If you have a email I could try that



damn, I've been here 2yrs and that's my 1st post ???

[jordyz]

Hi there,
I just fixed my leak. While I was back home, I went to a shop that specialized in rebuilding perkins and got a rebuild package for that particular leaking problem. It consisted of 3 o-rings, a small gasket and two small bolt rubber washers. That was the easy part. Eeven though my engine is easy access, getting the throttle control mechanism out was the hard part as it is under the exhaust manifold. I did not remove the injector pump.

[jenny2]

Originally Posted by jordyz

Hi there,
I just fixed my leak. While I was back home, I went to a shop that specialized in rebuilding perkins and got a rebuild package for that particular leaking problem. It consisted of 3 o-rings, a small gasket and two small bolt rubber washers. That was the easy part. Eeven though my engine is easy access, getting the throttle control mechanism out was the hard part as it is under the exhaust manifold. I did not remove the injector pump.

they can be a pain to get to and to prime one that has ran out of fule I use to leave a wrench tied to a string that I was moving with alge infected fule tanks even with a 2 micron racor before the primary filter they are very sensitive to trash verses a plunger type pump

[Kaitsu]

Originally Posted by jordyz

Hi there,
I just fixed my leak. While I was back home, I went to a shop that specialized in rebuilding perkins and got a rebuild package for that particular leaking problem. It consisted of 3 o-rings, a small gasket and two small bolt rubber washers. That was the easy part. Eeven though my engine is easy access, getting the throttle control mechanism out was the hard part as it is under the exhaust manifold. I did not remove the injector pump.

Greetings from Finland! I have the same problem with my good old Perkins 4108M '76. I searched the web and noticed your post.
Where did you get that service kit, does it have a code? How much that costs? Would that seal kit fit in to all models? I know there are variations on the pumps.

Regards,

Kai

[Hillbillyfunk]

before you go out and spend a bunch of money replacing an injector pump let me relay this event:

A friend of mine showed up in the Bahamas with a leaking injector pump on a Perkins 108, at some shop in KW he was quoted $3,000 to rebuild it despite the fact that it didn't need to be rebuilt (rip-off shop) I took a look at it and was able to replace the rubber "O" rings in the throttle control, I have a set of O rings that I picked up from Harbor Freight tools for $3, darn near every size needed contained therein. A pair of 12pt head bolts that mate to a 7mm socket easily remove this part without pulling the injector pump the trottle controls just snap into place without any nuts or bolts holding them in, remove from pump and pull the shaft the throttle lever is connected to out

There was still fuel leaking from the copper crush rings (smash gaskets) from the injection lines being loosened too many times for bleeding the system, without a good parts store anywhere nearby I was forced to make new copper crush rings. I took a few bits of copper pipe (that I always have around) and cut thin slices off the end with a pipe cutter, then filed them smooth, viola! no more leaks, $3,000 saved.

hope someone else can benefit from this trick

[Unicorn Dreams]

Go to the Sricky's on this forum and you can download shop manuals for your 4-108

[Kaitsu]

Thanks for the tips and already fixed the problem, but forgot to put it here.

I got the the rebuild seal package which included all necessary seals and O-rings (5 pcs) to fix the governator and throttle arm leak.
The task itself was not that simple because I needed to remove the exhaust manifold and 1 fuel pipe before able to access the 2 mounting bolts of the governator and able to pull it off the pump.

Of course one of the manifold retaining nuts (4th cylinder) was in place where you cannot reach with common tool and also needed loosen another fuel pipe from atomizer and bend it a little to be able to reach the nut. Need to use swivel and extension with small ratchet and it took quite a while to open.

As I needed to remove the exhaust manifold from the block and off the heat exchanger, I pulled also the coolant reservoir and renewed some water hoses between those units. (needed new paper seals as well for the joints).

The attached photos; 1st shows the governator unit and how it's under the exhaust manifold and fuel pipe. 2nd one shows the governator unit tear down and the 2 axels where the leaking o-rings were. On the right old o-rings and the mounting bolt seals as well the seal between the pump chassy and governator.

I cleaned all parts with petrol and air (compressor). The new O-rings need some force to put in place and you need to stretch them with e.g. small screwdriver. Before that, I did coat them with some engine oil.

Kaitsu