17prospective buyer

Do they include the tiny 1mm I.D hose that is used by the vacuum actuated HVAC system and FPR's? The pics i see of them seem to indicate that the smallest diameter hose in them is for those lines i mentioned.

Hilton

I've been removing the silicone vacuum hoses from my 928's (except the one from the flappy diaphragm to the solenoid - as that requires removal of the intake to get at, and doesn't have the risk of carrying fuel).

I originally put silicone on when doing intake refresh - however silicone doesn't fare well in gasoline, and if the FPR or Dampeners spring a leak in their diaphragm (which is their mode of age-related failure), then your vacuum hoses will fail pretty rapidly, letting gasoline into the engine bay.

The factory setup of plastic lines and rubber elbows at least resists fuel enough that you'll get longer to notice rough-running due to fuel pressure issues.

As to kits and the HVAC stuff - I haven't seen any kits which include the additional colours/lengths needed to do the HVAC lines. They usually focus on the bits to reach the pressure regulator, dampeners, flappy, charcoal canister, air pump valve etc. (which all takes about 8 feet from memory)

Ethre

If I recall correctly I used closer to 10 feet on mine (bought hose by the foot, not in a kit). Probably varies by year though. Don't forget the two hoses to the distributor on early cars.

I found that I only really needed two diameters of hose though (3 mm fit tightly on all the small stuff, 10 (?) mm on the larger lines).

17prospective buyer

Guess there's no point in replacing those tiny diameter lines, they don't really degrade (i think they are PVC maybe?).

danglerb

I bought the kit from Roger, hard small lines that are easy to route with rubber elbows and T etc.

Over time the hard lines get brittle, but regardless, go in do it right, do it once, and don't assume any of the lines are routed correctly.

Speedtoys

Watch the silicone lines where california or states that follow CARB standards might peek.

Silicone hoses seep hydrocarbons at a really amazing rate..so they dont like them.

AFAIK, they dont care about intake routing, but vacuum is iffy I think, crank venting..right now.


Besides..as they seep/leak, they get dirty too.

Just for people in insanely crazy inspection areas...

17prospective buyer

Luckily no need to worry about that in Canada. 87 is the last year that you don't need an E-test, and the car is in a rural area, so even for newer cars i don't need to E-test. As a redundancy, i work in a shop and could just buy some beer for the engine/emissions tech and he'll write me up a "fake E-test".

I'll do all this at least before the motor goes back inside.

dcrasta

If you insist on using silicone hoses (I dont recommend them) get the thick wall type that wont collapse under vacuum.
Dont forget the modulator vacuum line that goes to the transmission (auto-only).
You may want to replace the '7 way spider' (Not sure if you have one) .. I rigged one up using a bunch of vacuum 'T's or you can get a 7 port manifold (Ebay).