Finding generic parts like vacuum lines and clamps

[FireFox31]

Certain parts on our cars are generic such as vacuum lines, hose clamps, nuts, and bolts. Yet, each one has so many specific attributes that it's difficult to find generic replacements of the exact part. Fine, determine the Volvo part number and pay more for that. But what do we do when the part number isn't available? How do you find generic parts to the correct specs?

I'm trying to find the intake manifold absolute pressure (MAP) vacuum line. VolvoPartsWebStore doesn't show it on its intake diagram. I roughly know the specs of the hose (13" long, 1/2" OD, 5/16" ID, yellow stripe), but I don't know its wall thickness, pressure specs, etc. I have similar doubts about finding any vacuum line, thus haven't replaced any.

The clamps I'm looking for are single-use ear (pinch) style. I know the oil trap inlet pipe was Oetiker 346. FCP and VPWS say the oil trap clamp is 976584 but it is a screw style which was a little too small. No, I can't easily use worm gear clamps because their band width is too wide, not sitting correctly on the barb or hitting other components. Trying to find these clamps has revealed there are multiple band thicknesses, metals (probably stainless), and more attributes. I can't easily find where to get them.

Don't get me started on nuts and bolts. I visited a warehouse specifically for fasteners and couldn't find the special wide spaced threaded screws for the radiator fan, ultimately paying Volvo a lot for them. Even for simple stuff like metric bolts, I suspect the official Volvo part uses a specific metal, coating, and other attributes. I paid $4 per bolt for my bumper brackets, then overtorqued one, stripping the hole, now must tap it larger, but would like a larger bolt with the same specs.

Trying to find the correct parts for this car takes a lot of time. Then I must find the right install procedures, torque specs, and tips not in the manual. Then I must do the actual work, find an unexpected problem, and do the work a second time. Wow, I spend a lot of time on this car.

[850oldschool]

I've found manufacturer catalogs to be very helpful in finding the generic parts.

Oetiker is here:

https://www.oetiker.com/-/media/Files/O ... og_EN.ashx

Gates is here:

https://www.gates.com/content/dam/gates ... atalog.pdf

[volvolugnut]

In the cases where semi generic hose parts are no longer available, you may be able to get the advice of a knowledgeable auto parts counter guy. A good one with gray hair may be able to advise what will be a good replacement. You will have to shop around to find a counter guy who knows more than how to look up parts on the computer listing. My experience with NAPA stores has been better than with OReilly or Auto Zone.
For fasteners, I have some success with the larger hardware stores that have trays of specialty fasteners for self service selection. Online is not so useful, because you can't measure and examine the fine details of the offerings.
Ultimately, you or someone will need to decide if the part meets the specifications of the application. As a mechanical engineer by training and long practice, I feel I can do this well for mechanical parts. For electrical parts, I am less sure of what is a suitable replacement parts.

volvolugnut