ESP Sealant: New Application & Repair | Posts 16+

Now I finally found the time to re-seal my ESP.
So, the time between Christmas and New Year's Eve can actually be used in a meaningful way...

'A couple of good guides on ESP cleaning and sealing from our forum were helpful. With some prior knowledge and the necessary tools, there's nothing standing in the way of a repair.'

After approximately 6 years of using biodiesel (initially alternating with regular diesel, then only biodiesel), the ESP (Exhaust Gas Recirculation) system was completely clean and free of deposits.
I replaced all the seals except for the oval side seal with the MSW (motor-starter unit). To my surprise, half of the original seals were already green, meaning they were made of Viton. These Viton seals were still completely intact and elastic. The other three normal black seals (between the cover and the MSW, between the MSW and the housing, and between the housing and the HD - hydraulic drive) were shrunken and brittle.
Replacing the seals was not difficult, provided you exercise caution and patience (see technical manuals), but the 20mm shaft seal presented a small challenge. I made a few small holes and then pulled the ring out. It is crucial to prevent any metal shavings from entering the pump, as this would likely cause it to fail quickly.

Once the ESP was reinstalled and we were working on the new ZR, we noticed that there was some shaft play, approximately 1-1.5mm, along the pump shaft. However, we didn't remove any spacers or shims, I'm certain of that. Now that I think about it, I didn't check the pump for this before disassembling it.
What do the experts say, is it normal to have a 'small' game?

Otherwise, if the impeller and bearing housing are not properly seated, there will be no noticeable play. For the past few days and over several hundred kilometers, the pump has been absolutely leak-proof, but this slight impeller play is still bothering me...

Has anyone else had similar experiences?

Best regards, Georg.

Supplement to my post from October 9, 2005 (At that time, the mileage was 210,000 km, now it's 390,000 km).

Bosch VP37 fuel injection pump gasket set.
Bosch 2 467 010 003

After more than 8 years and 180,000 km, I had to have the fuel injection pump resealed again.

Over the period from 2005 to 2009, I pumped approximately 3000 liters of vegetable oil through the pump.
I used a Schur mixture.
It was now leaking at the shaft seal and the O-ring on the rear injection control valve.

I also immediately replaced the O-ring from the high-pressure part/head and the solenoid valve/2 pieces.

The shaft seal and the O-ring of the splash guard were hard and brittle, which is why there is a leak.
On the other hand, the O-ring from the high-pressure part/head and the solenoid valve/2 pieces (not replaced in 2005).
To my surprise, they were still quite soft and good.

The pump inside is very clean, with no deposits. I haven't used PÖL for 5 years.
There is approximately 1mm of axial play, and supposedly the tolerance limit is 0.3mm.
Who can confirm this for me?
Radial play of approximately 0.1-0.2 mm is present.
Clean surface, no scratches.

I plan to drive my Golf 3 TDI with a 1Z engine for another 6 months (it has a valid technical inspection until October 2015).
With heavy hearts, we will part ways.

Hello.
Jarek

Hi.

Thank you for sharing your experience. I've also had leaks on my cars from time to time - usually it's the flow meter or the cap on my VP37.
"The previous owner of my main car, which I bought 11 years ago, used RME. There was an immediate and significant leak issue, likely because I only used diesel fuel. However, I also understand that this can happen with RME."

What I don't quite understand is why vegetable oil is supposedly so harmful to the seals. I often use it in the summer without any modifications. Is there an explanation for this?
Okay, the gasket isn't that expensive, but the job isn't exactly fun - especially when it comes to adjusting the flow meter and then readjusting it.

Best regards,