vacuum lines

[vortecfiero]

I have always used brake line for vacuum lines because I think it may make the
vacuum signal more accurate. If the usual rubbe stuff or silicone stuff collapses
slightly or expands to a certain point... it could slow down the full reading till it hits
that point.

also the carefully bent and painted brake line looks nice if done carefully...

i have noticed that GM uses black rigid plastic lines.

am i thinking too much into this ?

 

[vortecfiero]

Re: vacuum lines

nudge

 

[bezerk]

Re: vacuum lines

good question. i wondered this myself for some time now. having weird boostcontroll issues with my ext. gate and controller.altough i can't imagine it will expend that much with such low vacuum/boost.

 

[Don W.]

Re: vacuum lines

Well logic would say that hard lines are not going to expand/collapse at all. As a test maybe you could replace the lines with semi rigid nylon (which would still give you some flexibility), using very short hose connectors at the ends. Wouldn't be that expensive. :2cents:

 

[SCWolverine]

Re: vacuum lines

i have noticed that GM uses black rigid plastic lines.

Cheaper, easier to route w/o having to tie them up along the run. With the total volume of (all) vacuum lines being so small, I wouldn't even consider the small variation as the source of any problems. I wouldn't use really cheap/thin-walled hose, for fear of it collapsing, but as far as swelling, it's have to be some real low end stuff if you could get it to swell with <30psi, even at a decent temp.

 

[dgoodhue]

Re: vacuum lines

I have pressurized my silicon vacuum lines and they didn't swell at all, maybe the cheap autozone ones that melt might swell, but otherwise I think you will be fine with a quality set of silicon vacuum hoses.

 

[hatrik8]

Re: vacuum lines

I would think even if they did swell or shrink, the volume change would be very tiny. :2cents:

 

[vortecfiero]

Re: vacuum lines

here is a pic of the first time i did fuel and hard vacuum lines.



yesterday i bent up new ones and will post pics soon. I will be painting them semi gloss black

 

[BoostedSUV]

Re: vacuum lines

I used a set of cheap auto zone silicone hoses on my truck and had all kinds of problems. Truck ran fine cold but once the engine warmed up it ran like crap. I lifted the hood one day with the engine running and noticed the silicone hoses got hot and sucked closed to the map sensor and to the AFPR. They also melted and closed shut to the cruise control unit. Definitely have to be careful with cheap vac hoses. They could cause potential issues. I battled mine for months before I realized what was going on... I switched back to standard rubber hoses and never had an issue. I also had the vac hose to brake booster suck closed and I lost power brakes at one point. Would only happen when under hood temps got warm enough to soften the silicone. Lesson learned!