I'm preparing to pull my TPI 305 from my '91 Camaro. The hard plastic vacume lines are breaking at the slightest touch in many cases. Before I continued:
1 - Is there a trick I'm missing (vs. "be careful"). They are breaking under the slightest pressure that I want to replace them all at this point.

2 - Can they be replaced by just the softer rubber lines?

3 - If not, is there a cheap solution? I'm assuming since they are hard plastic already shaped to route as they do, I'm assuming they are expensive. A flexible line option seems better.

Thanks for your help!

 

No trick. The plastic just goes brittle after years of heating/cooling etc. Take a piece to your nearest car shop and get the same stuff long enough to replace what you've got now. Don't need to be formed but allow extra length for longer bends.

 

Yup; even AZ has the plastic line, and all the fittings for it, hanging on cards back by the fuel filters and such. No need for the pre-bent; the factory just did it that way for manufacturing convenience.

But I'll let you in on a little trick: you can "pre-bend" the plastic stuff yourself, with a bit of GENTLY applied heat. A propane torch works great.

Or, you can go with rubber, no reason it won't work except in cases where the nipples are too far different sizes at the 2 ends for one size of rubber line to fit to both sizes of nipples.

 

Ive seen steel lines bent to replace the fragile plastic lines. Alot more time consuming, but itll never wear out

 

Before they invented plastic, even up through the 70s, that's what the factory used in ALOT of places. Vac adv in particular was almost always steel with just a short junction of rubber hose at each end.