Fuel pump replacement mystery hose

[patrickpawsey]

Hello,
This is my first post and also the recent proud family owner of a 1990 Autohomes Komet, with a 1.9 DG.
It's been having some trouble with starting after hot running, and it always comes down to fuel supply - as in there is not enough fuel coming through the pump.
I took it to Bromyard Vw who diagnosed a blockage in the fuel tank, and rebuilt the carb and put in a new fuel pump push rod.
This fixed it for a while but the same thing happened again recently: the van had a long run, hot, I went shopping and then came back and it ran then cut out after 5 secs. Looking at the carb and fuel lines they were dry. I put a temporary inline filter on and could see the pump wasn't pulling enough to re-prime the lines. The recovery guy used a manual priming bulb to re-prime the lines and then it fired and ran fine. (I've bought one of those priming bulbs now).
I got a garage to look at it and they said the push rod was worn down (about 4mm already when I compared it later to a new one from brickwerks) so they put a new one in and the pump is pulling better now.
However, so that I could compare how much the rod had worn down, and to get sone spares, I got some new ones and a new OE Pierburg pump from brickwerks
The pump on it at the moment is the cheapest one from brickwerks, so I'm inclined to replace it with the nice one and keep the cheap as an emergency spare.
What I'm not sure about is how to replace the pump - I know there are two bolts to undo, and I've got new gaskets and even a new plastic stand, and I've found some info that says to pack the lower chamber (presumably the bit with the arm the rod pushes on) with grease, but I didn't want to take it off without a good idea of the correct process to put a new one on - is it straightforward?
The other question I had is there is what I think is a vacuum tube that has come loose - it looks like one end goes on the top of the air filter and the other maybe goes on the carb. I've attached a picture of it hopefully it's clear enough to see.

Thanks
Patrick

PS I've added a picture of the van too

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[itchyfeet]

Pump is easy to change, just unbolts as you say, the plastic spacer may well be stuck in so it it is and unbroken just leave it.
I'd use some sealant on the gaskets as they tend to leak.

Seems unlikely the pump if changing the rod fixed it. Maybe just a low quality rod? buy from Brickwerks or VW Heratige.

[Mocki]

that vac ipe connects to the second spigot on the carb ( behind the car as you look at it ) without it the running will be bad .... if the pipe is damaged replace it , the system must be airtight to work

[patrickpawsey]

Thanks itchyfeet and Mocki, I will reattach the vac pipe having checked it's condition first.
I also suspect a soft push rod and have got the new ones from brickwerks (my first point of call now) and they seem more hardened.
I was inclined to change the pump anyway as I've bought the fancy one now and it keeps looking expensive in its box!
What sealant would you use on the pump gaskets? I've had some blue stuff I can't remember the name of before which I used on a gearbox to bell housing on a boat which seemed to do the trick!
Thanks again

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