Diesel Fuel Pump - top seals.

[Jack_It]

The other day I did the seals on the pump for the Golf, it wasn't a super hard job but you have to be very particular about how you do each step, and it does really help to record yourself as you go, it saved my arse...

I'll do my best to help you through with this little how-to.

First off - get your seals I was lucky and they had them in stock at my Diesel specialist workshop

They will need the pump details, if it's drive-able take the car in, if not I suggest a clear shot of the pump and the details, or jot everything down, it's on the front face of the pump, pretty easy to get to.




They also managed to have the shaft sleeve in stock!

First off, CLEAN, CLEAN CLEAN, I had degreased it before getting rego so the dust and light grime had gone, but cleaning it properly I focused on it with Wurth brake cleaner a brush and a rag. PLEASE WEAR GLOVES & EYE PROTECTION AT LEAST.



BEFORE - you'll also note I've removed the throttle cable, and throttle cable bracket from the pump, as well as most of the fuel lines.
Be aware there are washers under both bolts, and a spacer underneath the right hand mount.



AFTER - nice and clean, bracket gone and throttle cable tucked away


Undo the spring, BE CAREFUL, this bugger is tight, I used this handy little tool...


Carefully note the alignment of the shaft, I marked the screw point matching as best I could on the throttle arm
if they've never been done before, or a long time ago, the splines on the shaft will have worn, this is not ideal, but also helps marking where it has to go back. I marked everything while the throttle was closed. PHOTOGRAPH OR NOTE THE ANGLE OF THE SHAFT TOP, Score this too to be 100%


I made a few more markings, just to be 100% for the one on the shaft, it's marked as the forward facing half, but scratch it in, don't use something that will come off, however this is not super important as there is only one way the shaft will work properly when re-installed


Remove the throttle arm and spring, There is a spring washer below the nut, and the between the throttle arm and spring is a shaped washer/spacer thing that may be stuck to the arm, but it does come off... I dropped it between the glow plugs...



Clean around the shaft again, (Ignore that I've removed the bolts, I just forgot to take a pic)


MARK CAREFULLY the max fuel shaft, mine had a crimped lock on it, so it wasn't so bad. ALSO count the turns when un-winding it. Mine was 14. You will need this off to replace the seal. I marked a line from the body of the pump, to the lock nut, to the crimp, to the screw.


Remove the 4x top bolts with a 5mm allen key

it takes some force, but push the spline out of the lid of the pump, I held a big flat screwdriver on it and popped it out, you don't have much play in trying to lift the top off the pump, so try to keep it as close to the pump as possible.


I had to remove the shaft from this location, I don't know if you HAVE to, but I did because of the wear and tear
you can see the grooves in it here would not allow me to re-insert the shaft into the new bushing.


If you do, be very careful around here, there is a TINY cir-clip holding this on, then the spring housing, the spring, and that black cup, followed by A TINY WASHER.
IF YOU ARE NOT CAREFUL YOU CAN DROP THESE IN THE PUMP & GAME OVER.


I had to lightly linish the shaft with 1200 wet/dry to remove the bad burs and marks.


From the top, hammer out the old bush, I used a neatly fitting socket extension bar.
Clean it up, and lightly tap the new one in from the bottom, might also help to really lightly grease it with a bit of white grease or vaso to help it go in.



The new cap seal was a bit tricky, compared to the old one it had a heap more tabs, and when trying to squeeze it in it puckered up and stretched more than I thought, I ended up running around with a razor blade and taking off a few strategic tabs to help it seat properly


With the new O-rings, seals and bush in place, now it's time to return everything...

Apologies, the day was running long at the mechanic and I had to get it done - so no real pics, but it's basically reverse of un-doing everything.

I test fitted the throttle shaft in the bush, also greasing it lightly, it seated nicely.

Re-install the throttle shaft and spring assembly into the pump, This is where I stuffed up, DON'T PUT THIS ON BACKWARDS!
This will cause it to over rev and make you pull it all apart again...image of the highlighted cup is showing the correct orientation.


once that's done, re-insert the shaft into the pump top, it's a bit fiddly to get right but square it away and push it up as best you can, be sure to have the spine the right direction, you cannot rotate it properly if you don't, as if fouls on the body - you'll be able to tell.

Put your pump lid in place, bolting it down finger tight - screw the nut on the shaft fairly well, use this as a lever point for a screwdriver to pop the shaft the rest of the way up - it has to come quite a way.

Turn the shaft to replicate the angle of when you first took it all apart, with the marker to the front it should operate normally, you can use a screw driver to check, this action may drop it back down a little, so just put it back to the right angle and pop it up again


Remove the nut again, put the Spring on, the spacer washer thing, then the throttle arm, ensure the top of the spline lines up with the score marks, and if it's a bit worn, use the teeth to give you a good idea too - again doing this may push the shaft down a little, this time just pop it up from under the splines (NOT THE THREAD!)

Remember the spring washer, and put the nut on, don't worry if the shaft is a bit low, the nut should pull it up.

Remember that handy dandy hook? Use it to carefully re-attach the the throttle spring, it's a doozey.


Tighten up the 4 cap bolts, return the max fuel bolt, remembering the turns, and to align the markings - or if you're lucky like me, just tighten it till it can't go further due to the crimp!

Re attach the throttle cable bracket - remembering the spacers and fine washers.

Re attach the throttle cable.

on the furthest right injector there is a (on mine) a rubber cap on the overflow, take this off, perhaps attach a tube or you know just let diesel squirt everywhere... you'll need to clear the lines of air, so crank that sucker over!

it will take a bit to fire - it did with me anyway... there might be a better way to prime it, but my mechanic seemed happy with this method!

IF IT STARTS TO REV OUT, TURN IT OFF FAST. - you've done something wrong...

This happened to me, as mentioned earlier I put a part of the throttle spring on back to front, and this upped the idle way way high... it took an hour for us to sort what I did wrong thankfully I took all these pics and picked it after a review of them.

I think that's it, if I've skipped anything please let me know, I just completed a 1300k weekend with no drama's, the old girl returned 4.3L/100!

[jets]

Brilliant, 10/10. Very detailed & good workmanship. Thanks Jack.
Mods, could this be transferred into the Mk1 DIY & How To section or maybe under diesels?
With the age of these diesels this should now be a very common repair.

[Jack_It]

Diesel Pump - Imgur

Imgur album of super huge pics.