Bosch VE 10mm pump for ALH

[RetiringColt]

Hello everyone here goes my fird post! I have a early build 99 MKIV golf manual trans that has a leaking injection pump. It's coming from the 26mm triangular bolt. It's the one in the middle of the cast iron body in between the injector lines. The leak is about a drip every 3-4 seconds. Only dose it when the engine is cold. My parts diagram shows a ln O-ring that seals this part. If I remove this large triangular bolt to reseal will I change the piston calibration or damage anything? Doesn't look really complicated in there just haven't cracked one of these open yet. I have the special socket set and complete gasket kit coming and already have a VCDS. Just looking for some insight before I tackle this job. Thanks in advance everyone! Love this forum.

 

[Oledirtypearl86]

Are you sure it's that bolt and not the whole cast head there is a o ring on that and they are prone to leaking on my wife's 01 tdi I re sealed the head. Few times an the quantity adjuster gaskets on top. But every time I did it I had to re adjust my iq and if I rember that nut in the center of all the lines has a pretty stuff spring and shims behind it

 

[RetiringColt]

I've checked and rechecked. Cleaned and dried with break clean/compressed air. As far as I can tell its seeping out of the threads of that large triangular bolt. I only have a few minutes before it warms up and seals itself. Thanks for the warning about the spring and shims. I'm gonna try to repair in while on the car. It'll be about a week before I get those socks and seal kit.

 

[Oledirtypearl86]

There is a way to keep some tension on the spring and shims how far out does that nut have to come out ?

 

[Oledirtypearl86]

There is a way to keep some tension on the spring and shims how far out does that nut have to come out ?

 

[RetiringColt]

Ok got my socket set and seal kit. Had to remove the injector hard lines. Removed the 26mm triangular bolt. The old O-ring was hard as glass. Reinstalled with new O-ring. Had to crack injector lined to bleed air. No more leaks! I didn't have any shims or spring behind that bolt either but thanks for the warning. However I now have air intrusion at the fule filter return fitting. Replaced the O-rings there and it sealed it. I did notice if I tap on the top of the filter with the butt end of a screwdriver there is a small amount of air bubbles that get introduced into the fule. I pulled the fule sender at the tank because they are known to create restriction. I was right that thing was having to suck way too hard to draw fule. So I have an updated fule sender on its way. Apparently there was a check valve in the old sender fule supply side. The new ones have been updated and no longer have said check valve.

 

[RetiringColt]

Hello. I felt I should update my last little rant about the tank sender. Apparently not all of the new senders out there have an updated check valve. I purchased a new one and it was even more restrictive than my old one. Practically blocked completely. I did some more digging online and found that a lot of folks just remove the valve in the pickup side of the sump. I opted to go this rout. It is a delicate procedure but got it done. I immediately noticed a smoother idle. After a couple days of work commuting I can say the butt dyno feels a bit more mid to high range power. I was worried about engine start up without the check valve. It hasn't been a problem so far. Always starts right up and so far a great mod. Hope this helps someone.

 

[Oledirtypearl86]

Glad to hear you got it goin againe also on the fuel filters when I change filters I replace the o rings and lube with heavy grease and use a mighty vac on the return on the pump to prime the system it's a bit easier on the IP ask Wes my last ip had seen a bit of dry cranking trying to prime