Servo

[Andy Moltu]

Anyone know what the thread size used on the inlet manifold to PCV tapping is on a 4A.

 

Fitting a servo and ditching the PCV or open crank breathing via a catch tank, however the hose tail is way too big for usual vacuum hose.

 

Before anyone says don't fit one I prefer not to boot the brake pedal that hard since I ruptured my achilles last year.

[mikeh]

Hi Andy,

 

I've actually just removed the servo on my 4 and had quite a game trying to sort a blanking plug for the manifold tapping. In the end, I found a reference to it in the workshop manual as being 1/8" NPTF. As far as I can ascertain, this is effectively the same as NPT and the 1/8" NPT plug I bought certainly does the job.

 

Hope this helps

 

Regards

Mike

[TR NIALL]

Andy you can buy inline Hose Tails that are stepped as in 14mm one end 10mm the other,there are a lot of different variations.

[peejay4A]

I warmed the vacuum hose with a heat gun and it fits the takeoff just fine.

[Andy Moltu]

Hi Andy,

 

I've actually just removed the servo on my 4 and had quite a game trying to sort a blanking plug for the manifold tapping. In the end, I found a reference to it in the workshop manual as being 1/8" NPTF. As far as I can ascertain, this is effectively the same as NPT and the 1/8" NPT plug I bought certainly does the job.

 

Hope this helps

 

Regards

Mike

1/8 npt seems a bit small - I was referring to the tapping in the manifold that's used for the crankcase breather there is another tapped thread which may be 1/8th.

I could blank off the the tapping to the crank case breather and use the other tapped port on the inlet (which is blanked off)

 

Andy you can buy inline Hose Tails that are stepped as in 14mm one end 10mm the other,there are a lot of different variations.

I was aiming for a more elegant solution without the need for adaptors.

 

I warmed the vacuum hose with a heat gun and it fits the takeoff just fine.

 

The remote servo I've got uses a much smaller bore than the crank breather valve so stretching would not be an option -it's approx 1/2 inch on the manifold connection and perhaps 6-8mm on the vacuum pipe to the servo.

[peejay4A]

I just checked and my servo connection is 3/8 inch or 10mm so 8mm to 1/2 inch would be a bit much of a stretch.

[RobH]

Perhaps you need one of these:

 

https://www.amazon.co.uk/12mm-8mm-PLASTIC-REDUCER-ADAPTER-CONNECTOR/dp/B00JINIWMS

[Z320]

UNF 5/8-18