brake boost vacuum hose

[Targa Me]

Hello Everyone,
Can anyone tell me what size (I.D.) and length is the vacuum hose for the brake booster on a 84 Carrera.

Thanks in advance.

[KTL]

At what location do you need to replace it? It's not all one piece from the booster all the way back to the engine.

The parts diagrams say it's 12mm OD and 4mm ID. 4mm seems rather small to me, based on memory. But the hose has to be thick enough to prevent collapse due to suction. So 4mm would make sense even though I don't recall fittings that small connecting to the hoses

[Targa Me]

This is the hose that is in the engine bay next to the cruise control. the hose runs from there, through the firewall and connects underneath the engine where the tunnel begins. 4mm seems small, i would have guessed 12mm i.d.

[proffighter]

ID 12mm or 15/32" for sure, use only fuel hose with textil inlay

[KTL]

Must have misread the parts diagram. It shows 11,8 x 4 for that hose. 4 must be the hose wall thickness.

[Gunter]

12 mm I.D. sounds about right.

It can be bought by the foot off a roll; 1/2" will work. Look at the existing hose and follow it undrneath the engine to the tunnel. Estimate the length and add a foot to be sure.

You MUST specify that it is for vacuum; fuel hoses are different.

Vacuum hose is designed to prevent collapse.
Fuel hose is designed for pressure and to resist deterioration from gasoline.

[Jdub]

Smart fix - a leaking hose here has all sorts of bad implications. A simple test for our vaccum-assisted cars: Car off, pump brake pedal three times, apply easy, slight pressure to brake pedal and start car. If you feel the pedal pull in, away from your foot chances are the vaccum is still good.

Let me know how this goes - a solid piece of maintainence for sure!