Pump seal renewal

[tommin]

Okay I have decided after much research to attempt to renew the pump injector head seal with pump in situ. Seals are on order and have been reading up and watch some vids on how to do it. I will try and update with some pics as I go.

[tommin]

Okay that was quick, received a packet today all the way from Germany with a full set of seals, washers and the like for the pump.

Now before I start, as I will be replacing the seal whilst the pump is still in situ, I need to know which position the engine should be and how to achieve it, so as to maintain pressure on those springs in the distributor head to stop them dropping out?

Regards
Tom

[tommin]

Okay well that did not go so well..... Sorry no pics was so busy trying to sort my seal issue.

I first had a problem trying to release one of the injector nuts on the distributor head, it would not budge and it ended up undoing the internal injector nozzle???? When i took it out looked like some clown in a previous life had tried to do something to the pump and had cross threaded the blighter on?

I had no problem replacing the seal, that was a cinch, but alas that is where the good story ends. I reconnected everything left open the injectors to bleed system, and would it start, not a chance. It did cough once or twice but even with a battery booster connected, nowt, zippo, nothing.

I since noticed even though diesel flowed from some of the injectors, one injector nothing came through? Also at the same time I managed to break the stop solenoid connector (new ordered).

So I am at a loss at the moment. 3rd injector in looking from the back with no flow? Anyone have any ideas??????

Regards
Tom

[tommin]

Okay, well after giving the pump a little rest, went back out and tried again, now it looks as though all four injectors are starting to throw out air and diesel but still a non starter as i write, this i put down to the stop solenoid which i managed to break, so i will have to wait until the new one arrives to see if it was all worth it

[dave friday]

You could take the plunger out of the stop solenoid..though when if does start you'll have to stall the engine to stop it!!

[tommin]

Okay hopefully is this my final update.

Today I tried the plunger out as suggested by df, but no joy. What i did notice though there was not much pull on the diesel from the tank to the pump.

I am happy to say, that after connecting a 12v fuel pump I had originally purchased for my tractor (they sent me 2), between the filter and diesel pump, the old girl fired up first time, well after a few hic hic splutter splutter, but anyhow, touch wood all is okay. I am going to wire the new 12v pump in situ taking a feed from the stop solenoid wire, this will ensure a constant feed to the main pump.

It was a difficult job, so anyone going down this road, be fore warned, it is going to be painful, but it can be done......

[tommin]

A test ride this afternoon and the good news so far no leaks
I have one small issue though, sometimes the rpm stay up when foot off throttle. I checked the throttle linkage and all is as it should be so no problem there which leads me to believe there is something within the pump that is causing this. It could be some air as i know it can take some time to purge, but would welcome anyone who can input to what could be the cause behind it?
regards
Tom

[syncronized]

Might be the extra 12v fuel pump causing it. Have you tried removing it now its running again?

[tommin]

Yeah, i thought about that but the issue was happening prior to fitting the 12v pump in between. I will run the old girl a couple of days just to see if it clears, update whichever way it goes ......

[ghost123uk]

I have one small issue though, sometimes the rpm stay up when foot off throttle.

I am no Diesel expert and I know it's not likely to be this, but...

I am aware of the phenomenon of Diesel run away whereby the engine can run off it's own lubricating oil if too much back pressure in the crankcase forces oil / oily vapour into the air intake via the breather. I only mention this as I understand the consequences can be terminal, if not down right dangerous as you cannot shut it off Some examples here = http://www.youtube.com/watch?v=rLzf3ItkbOE" onclick="window.open(this.href);return false;

[tommin]

Ahhh interesting videos and one i hope not is an issue for me. How is the back pressure in the crank created? Is it to much oil or not enough oil, just to give me an idea if it turns out to be this drastic. The rpm does not increase like in the vids, just now and again it feels like it is sticking when i take my foot off the throttle, yet i know all linkage is okay?

I am wondering because it is not happening all the time could air entering the pump cause this, as I just done a hard drive to see how the pump is doing since the seal replacement and have noticed what i believe to be some small drips coming from the stop solenoid (still waiting new one) which could also be sucking in air? I dunno just chasing answers to my dilemma.
Tom

[ghost123uk]

I cannot answer most of those questions as I have never owned any Diesel vehicle so know little about them. However, I can say that excess crankcase pressure is caused by worn out piston rings and/or cylinder bores. This also usually causes a bit more oil consumption than is normal and may also produce a blue smoke from the exhaust, especially when under the higher loads (accelerating for instance). Excessive oil deposits in the breather pipe and the area where the breather pipe goes to the air inlet is also a common symptom of this, but there is always some signs of oil in there, so knowing what is excessive I'm afraid comes down to experience.

[tommin]

Well at least i now have a better understanding of crankcase pressure, thanks. I will keep an open mind at the moment, until at least i get the new stop solenoid in place, then I will see what is what and where to go from there.

[tommin]

Well that was quick, bought a solenoid from Latvia a couple of days back and here it is and fitted no problem

I have run the engine up to temperature (had to open cooling system, after taking pipe off) and looking at the the pump, can see no drips, and as i write no overrun on engine rpm

Job done .......................................... for now