vacuum lines ?

[Artie in Miami]

Each time I touch anything in the engine compartment of my 1986 suburban C20 5.7L 4bbl carb, one of the vacuum hoses breaks...they are very brittle. What I need to know is...if I wanted to replace all the vacuum hoses, what sizes would I need ? I plan on replacing them one at a time so I do not lose track of where they go.

[ACS]

I won’t comment on the size of the hoses for your 1986. My truck is a decade older and only has a couple of vac lines - which I replaced with black silicone vacuum hose. I got mine here, as they sell by the foot:
http://www.boostcontroller.com/Turbo...ose-s/2128.htm

[Wgesnerjr]

My buddy Brian got a hold of an 86 Nissan truck a few years ago. It had sat for 5 years and needed to be gone through. One of things was vacuum lines were junk and turned your finger black if you touched them. If they weren't spongy and oily, they were cracked and disintegrating.

Knowing he wanted to replace all the lines and that would entail many trips to the auto parts store, we decided to cut out the trip.

We went into the store and talked to the manager about our plans. He started a "tab" and we replaced all the hoses right in the parking lot! They would let us bring in a hose and help us size it correctly. Even sold us all the plastics tees and caps we needed. Took us almost 2 hours, but by the end; they would just wave us back behind the counter and record what we cut off on the "tab".

In all I think he spent about $50 bucks but the time savings was worth every penny.

[Gregski]

what I learned about vacuum hoses, they come in different sizes, so buy a couple different sizes by the foot and cut them to size, get yourself a proper sharp hose cutting tool, it's a game changer and don't cut them with a knife or a razor, it turns a hated task to one you can enjoy

not all the hoses are mandatory, I am not saying ditch them all, but know that some only come into play for that particular function of the carb and the carb has multiple functions ie systems in it, so slowly learn the essential hoses from the ancillary that will really help you with troubleshooting issues later on

get yourself some rubber plugs made to block off the ports for troubleshooting, if you already have some of these black nipple plug offs replace them with brand new ones as well, just cause they look OK doesn't mean they are not cracked

just because a hose looks good doesn't mean it is good, take one off and bend it over your finger and look for cracks

don't be afraid to sacrifice old hoses when you take them off, cut them on the nipples the long way so they split and come off easy, don't try to twist them off if they been on there for 37 years

avoid T connectors

remember a carb is just a controlled fuel leak, ha ha