Excessive vacuum in valve cover - **RESOLVED**

[ROH ECHT]

Right...the hose comes connected to an assembly: https://www.ecstuning.com/b-kayser-parts/brake-booster-hose/1k0612041gm~kay/?gclid=Cj0KCQjwhb36BRCfARIsAKcXh6GjJdZjQezAgWLUL6IGuo0syaFZviswWrY2f6g53bsx_JovU8T_PFgaAsWeEALw_wcB

[lloydy123]

Thanks, I was hoping to get a small length of that pipe or equivalent as opposed to having to buy the whole unit! But it may be my only option

[titchy]

I tried a repair then it split in a different place a few days latter bite the bullet renew it all

[ROH ECHT]

LOL, this ↓ always throws me off when I see it.
"There are no leaks remaining."
Sometimes I suggest checking it again...but I didn't.

[lloydy123]

LOL, this ↓ always throws me off when I see it.
"There are no leaks remaining."
Sometimes I suggest checking it again...but I didn't.

LOL! Sorry! It was leak free, but just for a heat cycle or two! I’m surprised I can’t find any loose hose to the correct vacuum standard, I’ll have to go to the stealer!

[LC5F]

All vacuum hoses that I can see online specifically say not to be used for the brake booster line!

They are covering themselves in case their part fails and you end up with no brakes

[lloydy123]

All vacuum hoses that I can see online specifically say not to be used for the brake booster line!

They are covering themselves in case their part fails and you end up with no brakes

Understood! So would any 8mm vacuum hose with good wall thickness do the trick? I think some folks use fuel line too

[Deano45]

The brake vacuum pipe or pipes come as one unit ...I had to buy one myself last month the good news it’s only £29 complete from vw.

[ROH ECHT]

Understood! So would any 8mm vacuum hose with good wall thickness do the trick? I think some folks use fuel line too

It has to be a non-collapsable tube. It will still have brakes, but it will take a heavy foot for them to work. And they fear this will catch someone off guard as we are used to the help of the brake booster.

[LC5F]

If one part of the hose has split, it is pretty certain the adjacent parts won't be far away from failure.

If it's a "get you home, road side repair" - yes chuck something in that wont crush under vacuum- as ROH ECHT said - and ideally resistant to heat and oil.

But for a permanent fix, that you don't need to worry about, replace the whole assembly...

[lloydy123]

You’ll be relived to hear I ordered the part from the stealer. £38!

[pudding]

Looks like your vacuum pump could do with a reseal judging by all the oil residue on it.  You can get an O ring kit from ebay to do that.  Simple job.

[lloydy123]

Looks like your vacuum pump could do with a reseal judging by all the oil residue on it.  You can get an O ring kit from ebay to do that.  Simple job.

I presume I just unscrew the end plate and apply the new seal?

[lloydy123]

Understood! So would any 8mm vacuum hose with good wall thickness do the trick? I think some folks use fuel line too

It has to be a non-collapsable tube. It will still have brakes, but it will take a heavy foot for them to work. And they fear this will catch someone off guard as we are used to the help of the brake booster.

I have replaced the brake booster hose with the official part from skoda and blocked off the extra vacuum port from the check valve. The vacuum is reading 13inHG from the dipstick which seems high. I understand that intake manifold vacuum should be 18-22inHG but should the crankcase vacuum not be much lower?


IMG_0945 by L Pat, on Flickr

[ROH ECHT]

My guess is there is a small crankcase leak somewhere. This could be a leaking seal where anything is connected to the head or block. I have seen a leaky rocker cover seal cause less vacuum at the dipstick. Could be a leaky oil filter housing seal.

Can you replace the dip-stick, remove the IAT sensor, and test intake manifold vacuum?

If the vacuum is more...then it likely has a small leak with something attached to the crankcase (high or low).
 
If you see the same vacuum...then you may need to disconnect the PCV tube from the intake manifold and plug both openings with the gauge toward the manifold. If vacuum stays where it was at the dipstick...then it may be a leak in the manifold itself or in something attached to it.