7 replies to this topic

[coyttl]

Model: 1992 Rover SPi
Year: 1992
Description of problem (please be as in depth as possible):

While removing my intake manifold, I had to cut the brake servo vacuum hose. The existing one had been on there far far too long, and would not come undone from any of the fittings. (Even after I brought the intake nut in, I had to use a blade and cut it from the fitting!)

Now I have a bit of hose that I need to get off of the servo itself, without damaging the right-angle fitting that connects to the hose and to the servo. It'd be easy if I could get the fitting out of the servo to cut the hose off, but am afraid to try until I know that it can be removed.

How does that vacuum hose connect to the servo? Can it come out of the servo without damage? Any tips on the best way to get it out?

Cheers,
Mike.

[pikey7]

you can prise the 90deg fitting straight from the servo housing. It's just a plastic clip with an o-ring to seal it. Once thats off, then use a sharp scalpel to slowly cut through the pipe to remove. Make sure you replace the pipe with proper non-collapsible stuff.

[coyttl]

you can prise the 90deg fitting straight from the servo housing. It's just a plastic clip with an o-ring to seal it. Once thats off, then use a sharp scalpel to slowly cut through the pipe to remove. Make sure you replace the pipe with proper non-collapsible stuff.

'K, thanks for the quick reply. I noticed mine was loose, but after finding that the hose is no longer available, wanted to prevent breaking something that would give me trouble in the future.

Cheers,
Mike.

[pikey7]

you can buy universal servo hose. just make sure you keep the fittings and the one way valve. And remember to cut it too long... the funny shape in the hose is to allow it to flex slightly as the engine moves.

[coyttl]

Cool, thanks.
Just tgot the adapter out - whew, that needed some force! Gonna get the hose tomorrow morning, and - pray tell the head'll be back on before the weekend.

Thanks,
Mike.

[dklawson]

If you use "generic" hose that is not rated for vacuum service (like heater hose) you run the risk of the hose collapsing under vacuum. You can still do this but you need to take one more step.

Take your new hose to a hardware store where extension springs are sold. Look for a spring that will just fit inside the hose. The spring should be at least 1/3 to 1/2 the length the hose will be when installed (including curves). When you get home, stretch the spring out to be almost as long as the hose will be when installed. Slip the spring inside the hose prior to connecting it to the servo and manifold.

The spring does two things: 1) it will allow you to bend the hose to the needed shape without kinking the hose and 2) the spring will prevent the hose from collapsing under vacuum.

[coyttl]

That's a good tip.

What about the issue of running oil/fuel in a hose that isn't meant to carry that? Won't the hose decay faster?

[dklawson]

Which hose are you concerned about?

If you are talking about the servo vacuum hose and replacing it with say... heater hose, you will not have any problems if you prevent it from kinking or collapsing. Most automotive hoses are made of Buna-N (Nitrile) rubber. Nitrile is compatible with fuel and oil. It is also the material used for the most common o-rings.

The servo vacuum hose will be exposed to some fuel vapors, but they will not harm the hose. Also remember that the engine will always be sucking air and pulling "stuff" down the servo hose.

The only area I know where extreme caution must be observed is with the brake hoses (to the wheels). Brake hose rubber is either a form of natural rubber (old components) or EPDM rubber. EPDM rubber is excellent at resisting brake fluid, heat, and steam. However, EPDM will fail VERY quickly if exposed to grease and oil. Likewise, Nitrile rubber (heater hoses, fuel line, and o-rings) will fail quickly when exposed to brake fluid.