Almost There!! It Runs!! :) and hemorrhages fuel :(

[JDiesel]

So my rebuild is going swimmingly.  (Swimming in ULSD that is....)

It fired up for the first time in three months today!  It ran beautifully but the throttle lever is leaking something terrible. 

I have read a similar thread here:  http://www.vwdiesel.net/forum/index.php?topic=31575.0
And a great pictorial on re-sealing the entire pump here:  http://www.vwdieselparts.com/forum/viewtopic.php?t=6694    (this one is pretty-awesome) 

So the bushing in the lid to my injection pump looks fine.  It is solid in there.  However, the o-ring on the throttle shaft looks extremely worn down.  This is what I would like to replace.  The local parts store has a "Fuel Injection System Re-Seal Kit  (Upper)"   for my pump.  It contains 8 small o-rings. (hah!)  I hope one of them is correct.     

I foresee a problem when I go to mount the top back down.  There is a squareish rubber seal that goes around the perimeter of the lid.   It is flattened.  I don't think that it will seal very well again.   Anyone have experience re-using these?  Is there a trick to it?    (Can I carefully cut one out of rubber?)

Otherwise a complete re-seal kit may be in my future. 

Thanks All,
J.D.

[Blocksmith]

Genuine Bosch seal kits are about $20-25 on ebay; I'd suggest just getting one and replacing all the seals at once, if you don't know the history of the pump. It'll probably save you time in the long run. 
Make sure to do the gov mod while you've got it apart     Does wonders for upper rpm pull.

[JDiesel]

Pump was great before I blue the engine up 
 
way over-reved, wrong downshift, y'all know the story.... 


I guess the high rpms made too much pressure in the pump?   I'm gonna try this one o-ring first, but will prolly end up resealing it.   
Can I use a thin (very thin)  line of RTV sealer for the pump lid? 

[8v-of-fury]

Can I use a thin (very thin)  line of RTV sealer for the pump lid? 

I'd use a diesel rated sealant. I have done it and would recommend it in a pinch. It works, so why not.

[JDiesel]

Cool, I will go this route. Thanks 8v.  As a side note for my Research and Development class (last year uw-stout)   I am reverse-engineering one of these pumps.   When I'm done dismantling it and filling out some silly worksheet I will reseal and have a spare pump. 

[8v-of-fury]

Cool, I will go this route. Thanks 8v.  As a side note for my Research and Development class (last year uw-stout)   I am reverse-engineering one of these pumps.   When I'm done dismantling it and filling out some silly worksheet I will reseal and have a spare pump. 

Keep it clean, it is paramount.

[theman53]

I would not try the silicone sealant. I think a Bosch dealer would get you the top gasket for $5 or buy the entire kit for $25, silicone inside this pump would be a disaster.

[8v-of-fury]

I have done it several times on my personal pumps when a gasket was not to be had immediately, and it sealed fine.

Even if a chunk made its way in to the pump, chances are it is not going to do anything but sit at the bottom or whirl around inside. The pickup for the distributor head (high pressure injection side of the pump) is at the very top, and it has a screen as well. Don't go over board and you won't have a problem. I'd say 1/16" bead or less directly on the seal, and let it cure almost completely before installing the lid.

[JDiesel]

Yes, I was thinking along those lines.   I am also ordering the full kit, I will use the rtv temporarily. (Like a week)  and then when the real gasket comes, switch it over.   Really would like the rabbit drive-able soon. Driveshaft is about to fall off the S10.

Oh, I picked up a small tube of RTV type sealant at NAPA. It says its resistant to Gasoline, Kerosine, and mild Acids.   All the other ones advised against using near gas completely.  I'm on my way to O'riely for the O-ring, maybe they will have some RTV that says Diesel on it.

[JDiesel]

Oh, while I'm here....

Does anyone here replace the nut on the tensioner with a stainless steel nut that has that nylon ring in it?  to prevent loosening due to vibration?  My bently refers to it as a "locknut"  but the nuts on  both heads I have are just normal lookin' nutz. 

J.D.

[Blocksmith]

I don't think there's really much of an issue with them vibrating loose. Myself, I wouldn't bother getting a nylon lock nut for it, but to each his own.

[damac]

i have never had a lid seal leak myself, maybe it was luck that in that area the rubber still seemed to be pliable and protruding a bit ready to be tightened and smashed down again.  i have had old pumps that were working, sprung a big leak like the high distribution end and replaced just that seal only to have another seal start leaking on the other side shortly after.

i personally completely break down, clean and reseal every pump i come across that has a tight mainshaft.  then i throw them on a car to test out.  i have had such bad luck in my short vw history with used parts going into daily service and then having old parts break down.  especially cars that sat.  injection pumps, wheel cylinders, etc.

there is a guy on ebay that will special order you whatever bosch stuff you need for cheaper if you buy directly.  last time i got a kit it was less than $20 to the door. 

[JDiesel]

Yes, I am ordering a bosch kit, and a dial indicator.   (I borrowed one for measuring piston height when I got my headgasket. Now if I'm going to be resealing the pump I bet I will have to set the timing on it.)


For the time being I went to Napa and found an o-ring that looked to be the right size for the throttle shaft.  I put the little guy on, tightened the lid down, and it works great. no leak, for now...   

didn't use the RTV like I thought I was going to, thought maybe the original lid gasket would hold- and it seems to be.   

Thanks for the help, cant wait to post a video of my 1.6 running.   (as soon as I figure out the strange battery drain thats going on. it never ends.)
J.D.

[hillfolk'r]

My dad had the pump redone in sootyvag like 12 yrs ago when he swapped in a 1.9......he seems to think he had it rebuilt by schied...they did a cool mod,they cut an extra groove in the throttle shaft,so it can be double o ringed.
cool idea fer sure...must be kinda tricky to do tho,chucking the shaft in a lathe without damaging it...maybe they put it in a bridgeport with a turntable?
anyone else heard of this mod?

[JDiesel]

That's a great mod. We have lathes in the machine shop here at school.  We have 3-jaw chucks and the kind of chuck that slowly tightens down with a Collet and a sleeve.  Lightly tightening the collet would allow you to widen that groove just fine without deforming the shaft where it was tightened.   Is the throttle shaft a common leak?   

b.t.w  My little rabbit is running great.   I just put 80 miles the rebuilt engine.  The fuel pump is not leaking at all.  I think I saw one puff of smoke out the exhaust when I was accelerating onto the highway during the whole 80 miles.  When I disconnect the pcv hose there is no oil spitting out. There is a slight hazy smoke coming out, not anything at all like it was before the rebuild though.   No oil leaks, no coolant leaks, no fuel leaks.  I did the retourqe on my a.r.p studs to 80 ft-lbs after the first time it reached full temp.  No cracked engine block. (11 mm threads,  whew.)    Also changed the oil, used diesel rated Rotella-T 10w30, new filter.    Constantly changed speeds and rpms on the highway. Never went above 65mph.   Super happy    but I need a new starter, it gave up the ghost after the first couple of times it had to start my new engine hah.

Thanks for the help, Im sure I will need it again. Pictures/video to follow   
J.D.
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